industrial applications of computational mechanics …katz_10/ computational dynamics 2 basic...
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Industrial Applications of Computational Mechanics
Dynamics
Prof. Dr.-Ing. Casimir Katz
SOFiSTiK AG
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Katz_10/ Computational Dynamics
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Basic Possibilities
• We may select a solution either
• in the time domain
• in the frequency domain
• The transformation between those methods is done with Fourier Analysis
• The Solution in the Time domain is
• easier to understand,
• more flexible
• Needs more computer power
• A complete solution in the frequency domain needs complex functional analysis,
but for small damping effects most can be handled in real analysis as well.
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Basic Equation in Time
• u = Displacement (Verschiebung)
• u· = Velocity (Geschwindigkeit)
• u · · = Acceleration (Beschleunigung)
• k = Stiffness => elastic/non linear support force
• m = Mass => Inertia force (Trägheitskraft)
• c = viscous Damping => Damping force
• p(t) = Loading
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( )m u c u k u p t + + =
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Discrete Equations in Time
• Discrete equations are the result of an weighted integration process
• Stiffness matrix kij is Sparse matrix
• Mass matrix mij is either
• Lumped diagonal matrix (ASE)
• Consistent sparse matrix (DYNA)
• Damping matrix cij is either
• A linear combination of m and k-matrix
• A consistent sparse matrix
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( )ij i ij i ij i jm u c u k u p t + + =
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Stiffness matrix
• Same as for static analysis
• Important part is the geometric stiffness (initial stress)
for many types of structures ! (e.g. string of guitar)
• If not defined / available:
• Free falling of object
• Suppressing degrees is therefore not allowed in general
• Fluids with K >0 and G ~ 0
• only possible for dynamic analysis.
• Special treatments for „incompressible elements“
• Stiffness of free surface in fluids !
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Mass matrix
• Care for correct units (tons, resp. kNsec2/m)
• Do not forget the permanent part of live loads (y2 = quasi permanent combination)
• Translatoric Masses are in general the same in all directions = uniform tensor.
• Rotational masses have an axis of rotation, thus are tensors with possible off
diagonal terms
• Especially if only translatoric masses are used, a sufficient small mesh size is
required.
= subdivide beams / cables
• Degrees of freedom without masses may lead to instabilities in the Eigenvalues.
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Damping
• Damping similar to mass:
• Moving part in oil / air / water
• Velocity dependant damping constants: f = c vx
• Damping similar to Stiffness:
• Material damping, cracking, yielding etc.
• Damping by friction
• If the displacement is known, an equivalent viscous damper may be used,
otherwise a non linear loading has to be analysed
• There is a negative damping possible!
• Aero-elastic instabilities, Galloping, Flutter
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Damping
• Modal Damping d or x
Estimates elastic plastic
• Concrete 1 – 2 % 7 %
• Prestr. Concrete 0.8 % 5 %
• Steel, bolted 1 % 7 %
• Steel, welded 0.4 % 4 %
• Timber 1 – 3 %
• Brickwork 1 – 2 %
• Cables 0.1 %
• logarithmic decrement d = ln(A1/A2)
• Rayleigh factors A / B
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Modal Damping => A,B
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Nonlinear Damping
• Hysteresis caused by yielding
• Friction
• Non linear Damping
(e.g. Jarret Shock Absorber)
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Frictional Damping
• Frictional force is not a real force but an upper limit
• We need (high) transverse spring constant to get such a force
• Equivalent viscous damping (Flesch equ. 5.24)
max
4equ
Nc
u
=
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Frictional Damping
SPRI 1 PRE -1000. CP 1. CT
1000000. MUE 0.5
spring shear component X 11001
Time
[sec] 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8
spring shear component X [kN]
-500.0
-400.0
-300.0
-200.0
-100.0
0.0
100.0spring shear component X 10001
Time
[sec] 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8
spring shear component X [kN]
-2.5
-2.0
-1.5
-1.0
-0.5
0.0
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7
13
6-5
00
Frictional damping Hysteresis
u
P
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Nonlinear damping
• For all damping effects holds:
decreasing the time step size does not decrease the damping force !
• Now we have the problem that the given parameters are valid only for some restricted
range of data
• V = 0.01 m/sec
• F = 0.631 * C for a = 0.1
• F = 0.158 * C for a = 0.4
• V = 2.5 m/sec
• F = 1.096 * C for a = 0.1
• F = 1.443 * C for a = 0.4
• Small values of a may become very difficult
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Non linear damping a = 1.5normal force 14001
Time
[sec] 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8
normal force [kN]
-2000.0
-1500.0
-1000.0
-500.0
0.0
500.0
1000.0
1500.0
-2 2
18
18
-19
37
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Non linear damping a = 0.5normal force 13001
Time
[sec] 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8
normal force [kN]
-1500.0
-1000.0
-500.0
0.0
500.0
-1 1
87
2-1
55
9
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Non linear damping a = 0.2
-1 1
86
8-1
57
8
normal force 12001
Time
[sec] 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8
normal force [kN]
-1500.0
-1000.0
-500.0
0.0
500.0
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Excessive damping a = 0.2
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normal force 12001
Time
[sec] 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8
normal force [kN]
-1000.0
-800.0
-600.0
-400.0
-200.0
0.0
200.0
400.0
600.0
Displacement uX 1
Time
[sec] 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8
Displacement uX [mm]
0.000
0.020
0.040
0.060
0.080
0.100
0.120
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Apply damping only for v>vmin
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SOFiSTiK AG * Bruckmannring 38 * 85764 OberschleissheimDYNR (V 10.53-33) 09.03.2016
Seite 5
Einmassenschwinger
Zeitverlauf
Zeitverlauf
Beschleunigung a-X 12
Zeit
[sec]5.0 10.0 15.0 20.0 25.0
Beschleunigung a-X [m/sec2]
-1.50
-1.00
-0.50
0.50
1.00
1.50
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Loading
• Constant or variant short time loading - e.g. Impact, discrete
earthquakes
p(t) = discrete short time function
• Harmonic loading - e.g. Machinery
p(t) = P · sin (W · t - j)
• Spectral loading - e.g. Wind, Standard Earthquakes
S() = defined Spectra
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How to solve dynamic problems
• Direct explicit Integration of the equations
• Very fast (no matrices are assembled)
• Allows any type of damping and non linearity
• Requires very small time step
• Direct implicit Integration of the equations
• Rather expensive (solving large sparse matrices)
• Allows any type of damping and non linearity
• Allows larger time steps
• Modal solution
• Evaluation of Eigenvalues (costly)
• Highly efficient and correct solution of equations
• Harmonic Response very easy (Frequency domain)
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Direct Integration
• An assumption about the acceleration within time
eg. as above, but other methods possible
• Solve system equations for a given time t
• Solving for t = to = explicit
• Solving for t > to = implicit
• Stability of implicit integration schemes ensures that numerical errors
are reduced (damped) within the integration
• Time step should be smaller than 1/4th of highest frequency
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( )( ) ( ( ) ( ))o
o o o
t tu u t u t t u t
t
−= + + −
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Implicit Integration
• Solve equations for a time in the future
• at t + t = classical Newmark scheme
• at t + • t = Wilson Theta scheme
• at t + (1-a)• t = Hughes alfa scheme
u••
t
t t+t
t+ (1-a)•t t+ •t
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Explicit Integration
• LS-DYNA / PAM-Crash etc.
Standard method for large short time dynamics
• Using a diagonal mass matrix allows fast solution
• Constraints however
• Time step has to be smaller than a stability limit
• Every node needs a mass
• Many time steps needed, so in general simplified one point
integrated elements are used
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FEX - Benchmark
Int. Dealer
Meeting 2012
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Newmark Scheme
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( )
( )
t t t t t t
2
t t t t t t t
u u t 1 u u
tu u t u 1 2 u 2 u
2
+ +
+ +
= + − +
= + + − +
( )
( ) ( )
2
t t t t t t t2
2
t t t t t t t t t
1 tu u u t u 1 2 u
t 2
tu u t 1 u u u t u 1 2 u
t 2
+ +
+ +
= − − − −
= + − + − − − −
A
U
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Displacement based Integration
• Establish equation for u at t+t
• Right-Hand Side with M,C-Matrix only
• Thus numerical effort is favourable
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t t t t t t2
t t t t t
t t t t t2
1K C M u F Cu Mu
t t
u u 1 u t 1 ut 2
1 1 1u u u 1 u
t t 2
+ +
+
+
+ + = − −
= + − + −
= + + −
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Acceleration based Integration
• Predictor values of velocity and displacements
• Establish equation for acceleration at t+t
• Right-Hand Side with C- and K-Matrix
• Thus, numerical effort is higher
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( )
( )
2
t t t t t t
t t t t
2
t t t t t
M tC t K u F Cu Ku
u u t 1 u
tu u t u 1 2 u
2
+ +
+
+
+ + = − −
= + −
= + + −
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Discrete Maximum Principle
• The off diagonal terms of the stiffness matrix have a negative sign
• The off diagonal terms of the mass matrix have a positive sign
• When combining both matrices to a system of equations:
• For a certain value of t the off diagonal terms change sign, giving rise to
oscillations in the solution
• Remedy: use lumped matrices
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2 2
EA EA A l A l
1 1l l 3 6S K M
EA EA A l A lt t
l l 6 3
+ −
= + = + − +
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Discrete Maximum Principle
u(x)
Aij < 0
Aij > 0 N(x)
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Non linear dynamics
• Most stability criteria are only valid for linear dynamics
• There are examples (pendulum) showing that Newmark
schemes may fail for non linear analysis
• Main Problem:
It is very difficult to establish a nonlinear implicit method
• Thus use explicit methods or very small time steps
• Use Iterations during each time step
• Extrapolate non linear effects for the implicit methods with simple
functions.
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Example Yielding of a Spring
• SPRI CP 1000000. DP 1000. YIEL 1500
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normal force 15001
Time
[sec] 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8
normal force [kN]
-1500.0
-1000.0
-500.0
0.0
500.0
1000.0
P
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Contact of a Spring (GAP)
• General Problem: Choose initial stiffness
• Stiffening is not always stable
• Softening may need a large number of iterations
• Good convergence only with Iteration / Line Search
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P
u
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Rather Soft Impact
SPRI 1 CP 1000000.
DP 10000.
SPRI 2 CP 1E7
GAP 0.001
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Soft Impact
SPRI 1 CP 1000000.
DP 10000.
SPRI 2 CP 1E8
GAP 0.001
YIEL 2000
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Hard Impact
SPRI 1 CP 1000000.
DP 10000.
SPRI 2 CP 1E10
GAP 0.001
YIEL 9999
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Train Bridge Interaction
• Dynamic effects caused by a train passing a bridge
• Resonance of Bridge (short bridges)
• Fatigue of bridge
• Comfort of passengers
• Derailment / Stability of Train
• Somehow a matter of mode
• Nobody knows the problem in detail
• So we have to do measurements
• And analysis ?!
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Train Bridge Interaction
• Which train ?
• HSLM A1 to A 10
• UIC
• ICE2, ICE3, Thalys etc.
• DIN Fachbericht / Eurocode: Fatigue relevant Trains
• How fast ?
• Bogie, spring and damper properties ?
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Task description
TrainPrescribed Movement
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• Bridge with moving loads
=> classical FE-Dynamics
• Train with prescribed track or pavement
=> classical Multi body dynamics
• Coupling of an elastic FE - Structure with a
Multi-Body-Dynamic-Program
• Simulation of two FE-Systems for the train
and the bridge with a classical FE-Program
Classification of
possible solutions
ADAMS
DADS
SIMPACK
RecurDyn
....
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The moving load
• For each node and each load there is a function describing which part of the
load is acting on which node along the time axis.
• Many nodes times many loads => many time functions
• Automatic realisation possible along a sequence of nodes
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node i -1 node i node i+1
F(i-1)
F(i)
Time
Time
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Contakt node / Contact point
• Deformation in contact point => Prescribed displacement for wheel contact node
• Force in contact spring => Loading for next time step
• Problem: different time values = integration is not consistent
principal problem also for Multi-Body-Dynamics
TrainPrescribed Movement
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Special Problems
• Wheel-Rail-contact
Hertz Pressure and much more
• Spring and damper properties for primary and secondary spring
• Non linear damper and spring behaviour
• Tilting and Transverse forces
• Bogie as separate body or subdivide it for each axle ?
• Track irregularities / Roughness of pavement easy to include but not available
easily.
• Impact if a load enters a predeformed structure
• Centrifugal forces
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And what’s that ?
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Solutions possible
• Change the integration parameters for the Newmark-Method
(delt>0.5)
• Wilson – Theta method
• Hilber-Hughes-Taylor-Alpha-Method
Should work without numerical damping and is specially suited
for non linear dynamics. However there is an higher effort
compared with the two methods above
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Comparison
Integration scheme a - wheel a - coach
Newmark d = 0.5 4612.47 0.66
Newmark d = 0.6 27.17 0.54
Newmark d = 0.7 10.96 0.52
Newmark d = 0.8 6.41 0.44
Hilber-Hughes Taylor a = -0.05 54.31 0.64
Hilber-Hughes Taylor a = -0.1 28.07 0.52
Hilber-Hughes Taylor a = -0.2 11.78 0.48
Hilber-Hughes Taylor a = -0.3 7.96 0.51
Wilson Theta Q = 1.4 3.59 0.43
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Example
3 spans of 88 / 160 / 88 m Height of pylons 18 / 46 m
Boxed girder sections with heights between 4.5 and 10.5 m
vertical Eigen-frequencies 0.88, 1.67, 2.22 Hertz, transverse from 0.30 Hertz
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Train
• Two coaches with 25.50 m length with two
bogies and four axis.
• Damping properties provided for two velocities
=> damping with exponential law
• For the safety against derailment one additional
torsional spring+damper was sufficient, to get
the forces for the individual wheel.
• Speed was 200 km/h.
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Moving Loads
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Moving Loads - Acceleration of bridge
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Moving Loads
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Train + Bridge - Acceleration of Bridge
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Displacements for the train
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Accelerations for the train
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Variation of contact force
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Derailment coefficient
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Eigenvalues and Modal analysis
• Eigen frequency or frequency of maximum response (resonance) ?
• Real or complex Eigenvalues ?
• What are Eigen forms ?
• What are Buckling Eigenvalues
• General mathematical property of a matrix
• Generalized Eigenvalue-Problem
A·X + l · B · X = 0
Eigenvalue Eigenform
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General Dynamic Eigenvalue problem
• There exist non vanishing solutions for this homogeneous equation leading to a
general complex eigenvalue problem.
• Damping c may be neglected in a first step or to be accounted for via a complex
eigenvalue solver.
• There exist as many Eigenvalues as the rank of the matrices
(but some may be zero)
• Each solution has an Eigenvalue li
(but there might be duplicate Eigenvalues)
• Each Eigenvalue has an associated Eigenform Fi
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0i rm u c u k ul l + + =
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Solution strategies
•
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Eigenvalue Solvers for Ax = l·Bx
• General Assumption: A,B positive definite (not always true)
• Classical complete methods (Cyclic Jacobi-Method / Householder)
• Vector-Iteration (gives the lowest eigenvalue): Ax(k) = l·Bx(k-1)
• Simultaneous Vector iteration in subspaces
• Solves for positive and negative eigenvalues
• Lanczos method (a direct solution)
• Generally the fastest, fails for negative Eigenvalues
• Bisection methods
• If only a certain range of values is required (not in SOFiSTiK)
• Rayleigh-Quotient-Method
• Makes best use of iterative Solver, positive eigenvalues only
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Transformations
• Any rotated coordinate system may be used to describe a physical or
mathematical behaviour:
• For a set of n variables the matrix T needs rank n
• Useful properties are:
• The determinant has the value 1
• Each row/column has a norm of 1
• Each row is orthogonal to each other
• Otherwise the transposed is not the inverse!
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local global
T
global local
u T u
u T u
=
=
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Usefull transformation:
Eigenvalues of an Area
• Principal axes of inertia of a cross section
• The axes are orthogonal
• The inertias have the lowest and largest value
• The off diagonal terms are zero
• The mathematical treatment is simplified by using the bending for the
principal axes.
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Usefull transformation:
Eigenvalues of a 3D Tensor
• Principal Stresses
• The stresses P1,P2,P3 have the extreme values
• Off diagonal terms (shear) vanishes in principal directions
• The directions of the P-stresses are orthogonal
but the direction is not of an absolute order.
P1 P2 P3
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Transformation to the base of Eigenvectors
• The Eigenforms are a good base of an vector space, as they are
orthogonal to each other
• So it is possible to transform the system of equations into that space by
two transformations
• As the scaling of the Eigenforms is arbitrary, it is very useful to scale
them properly
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global eigen
global global eigen
T T
eigen global eigen
u u
f A u A u
f f A u
= F
= = F
= F = F F
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A special kind of transformations
• A transformation may reduce the number of unknowns:
(e.g. a kind of a 2D shadow instead of a 4D solid)
• Some Information will be lost by this transformation
• However it is possible to transform in such a way that the most important
information is kept. (e.g. 2D drawings of 3D buildings)
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1311 12 14
2321 22 24
local global
T
global local
tt t tu u
tt t t
u T u
=
=
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Transformed Equations
in the Eigenform Space
2
( )
( ) ( )
(1)
( )
?
eigen eigen eigen eigen
T
eigen
T
T
T
M u C u K u f t
f t p t
M m Diag
K k Diag
C c
+ + =
= F
= F F =
= F F =
= F F =
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Modal Space or Sub-Space
• Mass and Stiffness matrix are pure diagonal matrices
• It is very often sufficient to use only a few (the lowest
eigenvalues) The modal loads may be used for a constant
acceleration to show the effectiveness of the subspace
• The C-Matrix is only diagonal for a complex Eigenvalue
analysis, or if the damping is a linear combination of the mass
and stiffness matrix (Rayleigh-Damping Coefficients)
• The damping is not very well known for most practical problems!
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Modal damping example
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Special Remarks
• Every Eigenvalue has its associated Eigenform.
• As the Eigenforms are displacements, any derived information
(velocities, accelerations, stresses, sum of reactions may be
calculated from those basic values)
• If we have the modal contribution (i.e. the modal response to the
modal load) we have a scaling factor for all other results.
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Zero Eigenvalues
• It happens (input error) or is intended (airplane) to have zero Eigenvalues
(= rigid body modes)
• This is a problem for many Eigenvalue solver strategies
• It can be overcome with an Eigenvalue shift
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( )
0
0
0
A x B x
A B x B x
l l
l l
l l l
= +
− =
= +
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SDOF-Response
• Eigenfrequency
• Forced vibration with a sine of
frequency W
(The response has the frequency of the
loading W !)
• Jump / Transition of phases from high
tuning ( > W, Loading and response
have similar directions) to low tuning (
< W, Loading and response have
opposite directions)
• In case of a resonance we have an
phase of T/4.
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Impedances / Impedance Functions
• Dynamic response in complex notation
• Dynamic stiffness with real and imaginary part (
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( )
; ( ) ( )( )
P tK P t K 1 2 i u t
u tx= = +
( )( ) Re( ) Im( )i tu t A e u i ujW −= = +
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Harmonic response of a MDOF
• Enforced Vibration with a Frequency W
• All Eigenforms have an amplitude A, a phase angle j, but the same frequency W
• The total response is the sum of all eigenforms
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A
j
1W2 3
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Impedance Functions
• A function giving the response as a function of the
frequency W
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Verschiebung uZ 244 Verschiebung uZ 250 Verschiebung uZ 284 Verschiebung uZ 290 Verschiebung uZ 244
Frequenz (Hertz) 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0
Verschiebung uZ
[mm]
-0.3000
-0.2000
-0.1000
0.0000
0.1000
0.2000
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Zeit [sec] 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8
Verschiebung zu 284 [mm]
-0.0500
0.0000
0.0500
0.1000
Transient explicit loading
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Verschiebung uX 1
Zeit
[sec] 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8
Verschiebung uX [mm]
-4.000
-3.000
-2.000
-1.000
0.000
1.000
2.000
3.000
4.000
5.000
Critical Damping z = 1.0
Verschiebung uX 1
Zeit
[sec] 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8
Verschiebung uX [mm]
0.000
0.500
1.000
1.500
2.000
Verschiebung uX 1
Zeit
[sec] 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8
Verschiebung uX [mm]
0.000
0.200
0.400
0.600
0.800
1.000
1.200
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2 DOF System
• Eigenforms have the same external Frequency W but different modal factors an
especially different phases
• Simple phases 0 / 180 degree introduced by sign of modal factors
• Maximum Response may be obtained by a time window of the steady state
response
• Maximum Response may be obtained by some mathematics (derivative = zero)
P = 10*sin(Wt)
m = 1000 kg
m = 1000 kg
k = 107 N/m kg
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Frequency response for the two storeys
• Response based on simplified phases
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Antiresonance
Zero values in Response ?
• It is considerably more effort to
account for the correct phases.
• Simulation of Phases with a sign
is appropriate for small damping.
• Reference solution available (no
Damping):
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Exact Response
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Comparison
u-2 u-3
Simplified Phase 7.456 mm 11.344 mm
Exact Phase 7.226 mm 11.491 mm
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Antiresonance
• Minimal movements of the first floor accelerate the second floor in resonance relative
to the first floor. Thus we know the frequency of that as the Eigenfrequency of the
topmost part of the structure alone.
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Multiple Periodic Lodings
• Independent “Out of balance” forces
f = 8.55 Hertz f = 33.11 Hertz
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Loading with same Phase
Frequency u-r = u-l
7 Hz 247
14 Hz 198
21 Hz 148
28 Hz 138
35 Hz 133
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Loading in opposite phase
Frequency u-r = -u-l
7 Hz 6
14 Hz 27
21 Hz 83
28 Hz 301
35 Hz 883
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Loading with arbitrary phase (SRSS)
u-r u-l
7 Hz 174 176
14 Hz 144 139
21 Hz 128 112
28 Hz 261 204
35 Hz 568 689
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Pitfalls for modal analysis
• The representative eigen
value has an ordinal number
much higher than expected
• A lot of low frequency
eigenvalues of cables with
low prestress
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Nonlinear modal Analysis
• Transient Solution in the modal space
• All spring elements may act in a nonlinear way and create residual
forces
• Very old, very fast method, introduced by Wilson
• Drawback:
• Does not work if the used Eigenforms have no contribution for the
nonlinear effects.
• This occurs if the linear stiffness is significantly higher than the
nonlinear behavior.
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Example Friction Pendulum
• Analysis time for 10000 time steps
• Non linear direct 21 sec 88 mm
• Non linear modal 2 sec 66 mm (30 EV)
72 mm (50 EV)
85 mm (100 EV)
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Man induced vibrations
• Exciting forces of 40 to 80 kg Mass with frequencies between 1.6 and
2.4 Hertz
• Rule of thumb to avoid frequencies below 5 Hertz is not sufficient
• Rule of thumb to avoid frequencies below 8 Hertz is to expensive
• Criteria for acceptance of accelerations 0.4 m/sec2
• Criteria for velocities
• KSB-values according to many national and international design codes
• Literature: Prof. Hugo Bachmann
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Traffic densities
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Traffic densities (HIVOSS)
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Problem: Acting Robots
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Problem: Acting Robot
• Large accelerations allow faster production cycles
• Fast movements will create acceleration forces
• There is very sensitive equipment in the same room
• If the fixing of a robot is moving itself the movements of the tip
are larger by an amplification function
• Special Circumstances
• Placement in the 2nd flour !
• A composite slab is very light
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Problem: Acting Robot
• Forces are unknown
But values in manufactures specifications were three times
higher than last model
• Movements and Synchronisation of robots is unknown
• Seeing a robot moving reveals considerably amplitudes
• Pushing at a robots arm reveals a rather soft construction of the
robot itself
• Technical descriptions are not available in detail
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Estimate the accelerations
• We have 84°/sec as speed with a load for the axis A2 and A3
• Accelerations for these axis may then reach 90 to 270 °/sec²
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t
t1
v
v-peak
v-mean 1
1
( 1)
(2 1) /
mean
v
a t
s v t
x x
x
= −
= −
=
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Frequencies
a = 90°/sec² t1 = 0.933 sec s1 = 78.4°
a = 180°/sec² t1 = 0.622 sec s1 = 52.2°
a = 270°/sec² t1 = 0.311 sec s1 = 26.1°
• The higher the accelerations, the shorter the period
• Highest frequency at 1/0.311 = 3.21 Hertz
• Expected Eigenfrequency of slab 6 - 10 Hertz
• So we have a high tuning
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Impact function
0.622 sec 1.0 P
Frequenz (Hertz) 2.0 4.0 6.0 8.0 10.0 12.0 14.0
Kraft [kN]
0.0
0.5
1.0
1.5
2.0
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Estimate the real forces
Acceleration referenced on Axis A2 Force Moment
Angle Radius vertical Mass vertical Axis A2
[°/sec²] [m] [m/sec²] [kg] [kN] [kNm]
Carousell 0 0 0 511 0 0,00
Lever 180 0,625 1,96 252 0,49 0,31
Arm 360 1,800 7,38 157 1,16 2,09
Hand 360 2,465 11,56 109 1,26 3,10
Pay load 0 3,050 15,23 210 3,20 9,75
Sum 1239 6,11 15,25
Lever a1=0.625*3.14=1.96 m/sec²
Arm a2=1.25*3.14+0.55*3.14*2=7.38 m/sec²
Hand a3=1.25*3.14+(1.1+0.23/2)*3.14*2=11.56 m/sec²
700
A2 A3
1100 1250 470 230
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Estimate the real forces
• Dynamic Loading varies between 2.8 and 6.1 kN
• The static loading would be a vertical sum of 12.4 kN
and a Moment of 12.76 kNm.
Do we have to expect 50 % dynamic loading ?
• For the design of the fixing the manufacturer has
specified vertical forces of 24 kN and a tilting moment
of 49 kNm. These loads include however extreme
events like an emergency stop.
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Uncertainties
• How often will we have extreme forces
• Empirical hope: only rare ?
• Repetition frequency of movements
• Empirical: slower movements on a more regular base
• Intermissions of movement
• Synchronisation
• Energetic Criteria: Square root of N
• Pedestrian Bridges: up to 25 % of people may act in phase
(lock in effect should not occur for robots)
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Assumptions
• One single robot acting unfavourably with a maximum impact
force and an empirical Synchronisation factor of 2.0
• Periodic movements with a mean acceleration of a single robot
with a factor of 10 (based on 100 robots) and an efficiency factor
of 50 % to account for the distributed loading and a factor of 0.25
for true synchronisation over a longer period
=> yielding a factor of 1.25
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Measurements
• The robots have provisions to avoid overloading of the gears,
reducing accelerations for large loadings or levers
• Although the existence of such a software was not denied, any
values about the quantity effect were not available.
• Measurements have been made.
• With some tricks it was possible to measure the effects.
• Measured forces emergency stop: 23.8 kN
Values from manufacturer: 24.0 kN
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Observations
• The arm of the robot is not very stiff. If one pushes with the hand
or simulates an emergency stop, large amplitudes may be
observed.
• For the standard case the electronic tries to avoid any sudden
acceleration. There are only rather smooth movements.
• The estimated forces are larger than the real forces. Further it
was observed, that the Axis A2 and A3 never worked in the
same sense. Accelerations / movements were always in
opposite rotational directions.
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Scaled Measurements
Acceleration referenced on Axis A2 Force Moment
Angle Radius vertical Mass vertical Axis A2
[°/sec²] [m] [m/sec²] [kg] [kN] [kNm]
Carousell 0 0 0 511 0 0,00
Lever 158 0,625 1,73 252 0,43 0,27
Arm 316 1,800 6,49 157 1,02 1,83
Hand 316 2,465 10,16 109 1,11 2,73
payload 0 3,050 13,39 100 1,34 4,08
Sum 1129 3,90 8,92
Lever a1=0.625*2,76=1.73 m/sec²
Arm a2=1.25*2,76+0.55*2,76*2=6.49 m/sec²
Hand a3=1.25*2,76+(1.1+0.23/2)*2,76*2=10.16 m/sec²
• Maximum Acceleration at arm 12 m/sec2
• Emergency stop with 35 m/sec2
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Analysis
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Eigen-Frequencies
EIGENFREQUENCIES [Hertz]
1 10.819
2 10.920
3 11.018
4 11.186
5 11.294
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Frequency dependant steady state loading
Verschiebung uZ 244 Verschiebung uZ 250 Verschiebung uZ 284 Verschiebung uZ 290 Verschiebung uZ 244
Frequenz (Hertz) 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0
Verschiebung uZ
[mm]
-0.3000
-0.2000
-0.1000
0.0000
0.1000
0.2000
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Impact loading at centre
Zeit [sec] 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8
Verschiebung zu 284 [mm]
-0.0500
0.0000
0.0500
0.1000
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Impact loading in neighbouring span
Zeit [sec] 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8
Verschiebung zu 290 [mm]
-0.0200
-0.0150
-0.0100
-0.0050
0.0000
0.0050
0.0100
0.0150
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Assessment
• For a one time loading we have an impact factor of
1.8 in the same span and values by a factor of 7
smaller from neighboured spans.
• As may be seen from the response, the slabs will
move within their own eigen frequencies. So we have
to select the impact factors for the robots for these
frequencies between 10 and 12 Hertz. Those values
are between 2 and 5, for some rare cases up to 9.
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Assessment
• Loading by a single robot enlarged with a resonance factor of 2.0
Moving at robot base 0.12 mm
• Loading from a steady state robot movement with a factor of 4 from the frequency
response
Moving at robot base 1.00 mm
• Assessed displacement from robot movements
at any point in the slab 0.24 mm
• Expected Movement of the robots hand with an amplification factor of 6
1.44 mm
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Damage within a sewage decanter
• 550 kg mass
• Speed is only 2m/min, but stop is always sudden
• => Impulse 18.3 [kgm/sec] = 0.183[kNsec]
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The damaged part
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Beam Analysis
• Eigenfrequencies 27.6 / 35.1 Hertz
• Static moment self weight 3.10 kNm
• Max. static moment 4.12 kNm
• Dynamic Displacements estimate 1.9 mm
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Calculated Displacements
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RESPONSE
Verschiebung u-X 4
Zeit
[sec]0.05 0.10 0.15 0.20 0.25
Verschiebung u-X [mm]
-2.000
-1.500
-1.000
-0.500
0.000
0.500
1.000
1.500
2.000
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Moments and Stresses
• Maximum in horizontal pipe 45 Mpa
• Maximum in junction 103 MPa
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FEM Analysis
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Static Analysis
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Dynamic Analysis (s = 230 MPa)
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Nonlinear modal Analysis
• Transient Solution in the modal space
• All spring elements may act in a nonlinear way and create
residual forces
• Very old, very fast method, introduced by Wilson
• Drawback:
• Does not work if the used Eigenforms have no contribution for the
nonlinear effects.
• This occurs if the linear stiffness is significantly higher than the
nonlinear behavior.
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Earthquakes
caused by plate tectonics
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Magnitudes
Richter
Magnitude
TNT
Energy
Example
-1.5 6 ounces Breaking a rock on a lab table
1 30 pounds Large Blast at a Construction Site
2 1 t Large Quarry or Mine Blast
4 1000 t Small Nuclear Weapon
5 80 000 t Little Skull Mtn., NV Quake, 1992
6 1 million t Double Spring Flat, NV Quake, 1994
7 32 million t Hyogo-Ken Nanbu, Japan Quake, 1995;
Largest Thermonuclear Weapon
8 1 billion t San Francisco, CA Quake, 1906
9 32 billion t Chilean Quake, 1960
10 1 trillion t San-Andreas type fault circling Earth
12 160 trillion t Fault Earth in half through center
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Seismic waves
• Compressive P
• Shear S
• Rayleigh R
• Love L
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Something happens between
• The waves are refracted and changed by all soils between the
epicentre and the site of our building
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Primary effects
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Secondary effects
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Loading by an earthquake
• Acceleration as a
function of time
• Measured
• Artificially generated
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Zeit
1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0
-0.40
-0.30
-0.20
-0.10
-0.00
0.10
0.20
0.30
0.40
[sec]
[sec]
Zeit
2.0 4.0 6.0 8.0 10.0
-0.80
-0.60
-0.40
-0.20
-0.00
0.20
0.40
0.60
0.80
1.00
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Earthquake Analysis
• There are a lot of measurements of earthquake accelerations
• You may generate artificial accelerations from a given spectra
• Problem is the check/conversion to a displacement history
• The standard analysis method is to switch to a moving coordinate system and
apply the loads as mass times acceleration
• This gives sometimes raise to understanding the meaning of the resulting
acceleration
• Problem of coherence for different base accelerations
• To be solved with different displacement histories
• To be solved with different influence functions for the accelerations
• Problem of eccentricity (given in design codes)
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Earthquake Analysis
• Methods to do the analysis
• Lateral Force Method
• Very crude, only for preliminary analysis
• Multimodal Spectral Analysis
• Most widely used
• Application to nonlinear systems limited
• Non-linear Static Method (PUSHOVER)
• Takes into consideration performance of the structure
• Transition between Linear Static and Direct Dynamic
• Direct Dynamic Analysis (linear and nonlinear)
• Correct, computationally extensive, only for structures of high importance
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The moving coordinate system
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( ) ( ) ( )
( ) ( ) ( ) ( ) 0
t t t
g t t
m u t c u t k u t
m u t u t c u t k u t
+ + =
+ + + =
൯𝑢𝑔(𝑡) + 𝑢(𝑡
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Dynamic Equation of SDOF
WCCM 2010 132
We are not interested in entire time-history, mostly in maximum
values (displacements, forces) => SPECTRUM.
Analytical solution – only for a certain type of loading.
For a general loading – integration of Duhamel‘s integral:
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How to obtain Response Spectrum?
UNSW 2010 133
New Accelelogram ag(t)
Sp
ec
tr. D
isp
l.
Sd
(t)
V. Alender (2004)
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Elastic Response Spectra (a) Pseudo
acceleration (b) Displacement
UNSW 2010 134
V. Alender (2004)
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Response Spectra
• A response spectra gives the maximum answer of a
SDOF (single degree of Freedom) system to a given
loading like an earthquake acceleration.
• The answer may be any value, but in general it is the
acceleration
• However two things got lost:
• The phase respective the time of the maximum
• The sign of the maximum value
Katz_10/ Computational Dynamics
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Response Spectra
• The design codes provide response spectra which
are an envelope to many observed or generated
events
Katz_10/ Computational Dynamics
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D= 2.00% D= 5.00% D= 10.00%
[sec]
4.003.002.001.000.00.0
8.00
6.00
4.00
2.00
0.0
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General Response Spectra (EC)
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Energetic Superposition
• We have the individual response of n Eigenforms but
we do not know how to combine them
• SRSS – (Square Root of Sum of Squares) Method
• The target result is always positive
(alternating load cases!)
• But what about the
corresponding forces ?
Katz_10/ Computational Dynamics
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Sign of Results
• Value of target for the case of absolute addition:
• Alternate Solution:
j ij
i
sum s=
1 0;
1 0
ij
i i i
iji
für sSUM f S f
für s
+ = =
− <
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Katz_10/ Computational Dynamics
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Sign of Results
• Value of target for the case of SRSS:
• Alternate Solution:
2
j ij
i
sum s=
2;
j
i i i
i ij
i
sSUM f S f
s= =
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CQC - Method
F1
F2
Method Loaddirection Transverse
History 100.2 4.9
SRSS 78.8 71.4
SUM ABS 127 116
SUM 127 6.1
CQC 100.8 6.0
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Directional superposition
• EN 1998-1 4.3.3.5.1
(1) In general the horizontal components of the
seismic action shall be taken as acting simultaneously.
(7) When using non-linear time-history analysis and
employing a spatial model of the structure,
simultaneously acting accelerograms shall be taken
as acting in both horizontal directions.
• An error in assumption ?
• Adding a second (even reduced) acceleration in a transverse direction is
equivalent to a one directional earthquake of larger magnitude in that other
direction !
Katz_10/ Computational Dynamics
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Katz_10/ Computational Dynamics
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Directional superposition (old style)
• Classical:
PROG MAXIMAKOPF EXTREMA FOR EARTHQUAKE USING RESPONSE SPECTRAKOMB 3 STAN301 A4 1.3 $ earthquake X301 A4 −1.3304 A4 1.3 $ earthquake Y304 A4 −1.3307 A4 1.3 $ earthquake Z307 A4 −1.3301 A4 1.3*0.7 ; 304 F 1.3*0.7301 A4 −1.3*0.7 ; 304 F 1.3*0.7301 A4 −1.3*0.7 ; 304 F −1.3*0.7301 A4 1.3*0.7 ; 304 F −1.3*0.7
etc…
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Directional with SRSS (EN 1998-1 4.3.3.5)
a. The structural response to each component shall be evaluated separately, using
the combination rules for modal responses given in 4.3.3.3.2.
b. The maximum value of each action effect on the structure due to the two
horizontal components of the seismic action may then be estimated by the
square root of the sum of the squared values of the action effect due to each
horizontal component. More accurate models may be used for the estimation of
the probable simultaneous values of more than one action effect due to the two
horizontal components of the seismic action.
c. As an simplified alternative with combination of effects:
EEdx “+” 0.30 EEdy and EEdy “+” 0.30 EEdx
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Example for a better SRSS solution
• Column with diagonal (multiple) Eigenvalues
Eigenform 1
MY = -1633
MZ = +2412
Eigenform 2
MY = -2412
MZ = -1633
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Acceleration in Diagonal Directions of
Eigenvalues• Acceleration
in two load cases for +45° and -45°
• Result are maximum moments:
Load case 11: My 33.32 MZ - 33.32
Load case 12: My 33.32 MZ 33.32
• Perfect Symmetry has been achieved only by CQC-Method !
• Combination of both directions with signed SRSS:
Load case 21: My 47.12 MZ 0.00
Load case 22: My 0.00 MZ 47.12
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Intermission
• We did not request for the maximum corner stress but for the
maximum moment My.
• This is obtained by an acceleration in the local z-axis. But then
the acceleration and the forces in the transverse direction are
zero!
Thus directional load cases identical to 21 and 22
• So if we add the two diagonal directions by the SRSS-Method
we have to provide for the correct sign of the superposition
according to the superposition of the Eigenvalues!
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Other results possible?
• Combining the maximum absolute values (?):
load case 33 My 47.12 Mz 47.12
load case 34 My 47.12 Mz 47.12
• Combining the Ex 0.3Ey on LC 11 and 12:
load case 33 My 43.32 Mz 23.32
load case 34 Mz 43.32 My 23.32
• Combining the Ex 0.3Ey on LC 21 and 22:
load case 33 My 47.12 My 10.00
load case 34 Mz 47.12 My 10.00
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Direct integration with Time Histories
• Generate artificial earthquakes from design code
response spectra
Katz_10/ Computational Dynamics
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How many Histories?
• design code EN 1998: at least 3, recommended 5
• Newer recommendations of the ASCE require 11
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Comparison for given Example
Katz_10/ Computational Dynamics
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max My zug. Mz min My zug. Mz max Mz zug. My min Mz zug. My
Transient 1 58,53 15,30 -66,77 -18,65 57,42 -19,29 -53,82 -17,57
Transient 2 62,36 -21,17 -49,95 22,20 59,06 6,66 -53,26 -6,11
Transient 3 46,06 7,07 -42,61 -3,50 41,78 8,29 -44,60 -11,81
Mean(1-11) 55,14 -0,16 -57,03 3,47 55,75 4,66 -56,56 -10,81
SRSS 47,52 0,00 -47,52 0,00 47,52 0,00 -47,52 0,00
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Alternate approaches
• Drawbacks
• Statistical Results are quite better now but still not perfect
• No non linear effects so far
• Phase differences may become important for larger
structures
• Possible Extensions
• Direct Time Integration with many artificially generated
earthquakes
• Push-Over-Analysis
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Why go NONLINEAR?
WCCM 2010 153
• Earthquake is a displacement, not a force!
• Earthquake is a probabilistic event – Should we invest into
something that might not even happen (Tp=475 years)?
• Earthquake is a powerful force of nature (ag=1.0g)
• Price to be paid for nonlinearity – Ductility!
Nonlinear
response
Elastic
response
Damage
PARADOX?
Smaller force –
Higher
damage
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Nonlinear (Design) Response Spectrum
WCCM 2010 154
q ≈ μd
V. Alender (2004)
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Behaviour factor q
WCCM 2010 155
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Concept of calculation of the structures
using Nonlinear Response Spectrum
UNSW 2010 156
V. Alender (2004)
Design seismic
forceCross section
design
estimat
e
μd trough
design of
details
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PUSHOVER Analysis
WCCM 2010 157
• Static nonlinear procedure
• Comprises of two steps
1) Determination of the capacity of the structure under a
specified loading patern
2) Determination of the performance of the structure under a
chosen demand (Earthquake) and a given capacity
• In earthquake (and dynamic in general) analysis demand
depends also on the capacity of the structure (stiffnes,
ductility, etc.).
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ADRS - Spectra
• Converting the Time-
Scale into a spectral
displacement
(based on the harmonic
relation)
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Performance Analysis
Katz_10/ Computational Dynamics
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Katz_10/ Computational Dynamics
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Push-Over-Loading
• Apply a representative horizontal acceleration
From Static to „Dynamic“
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Push-Over-Curve
• Base Shear Force as a function of a characteristic
roof displacement
• Convert to the ADRS-Format
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Conversion
• Simplification
mi fi2 = 1.0
Total
Sa g
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Capacity curve (Spectrum)
WCCM 2010 163
[mm]
1002.000989.000976.000963.000950.000937.000924.000911.000898.000885.000872.000859.000846.000833.000820.000807.000794.000781.000768.000755.000742.000729.000716.000703.000690.000677.000664.000651.000638.000625.000612.000599.000586.000573.000560.000547.000534.000521.000508.000495.000482.000469.000456.000443.000430.000417.000404.000391.000378.000365.000352.000339.000326.000313.000300.000287.000274.000261.000248.000235.000222.000209.000196.000183.000170.000157.000144.000131.000118.000105.000
92.00079.00066.00053.00040.00027.00014.0001.000
-10.000
1.30
1.20
1.10
1.00
0.900
0.800
0.700
0.600
0.500
0.400
0.300
0.200
0.100
0.0
M 1 : 162XY
Z
0.585 0.585
0.5540.554
0.507 0.507
0.442 0.442
0.3600.360
0.293 0.293
0.2770.277
0.267 0.267
0.2530.253
0.221 0.221
0.1800.180
0.165 0.165
0.1330.133
0.083 0.083
0.067 0.067 0.0340.034
Nodal load (f orce) v ector, Loadcase 911 , 1 cm 3D = 0.418 kN (Max=0.585) (total: 8.84)
m-10.00 -5.00 0.00 5.00 10.00 15.00 20.00 25.000.00
-5.00
-10.00
-15.00
-20.00Load pattern
according to
first Eigen
mode
IO LSC
P
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Structural Performance Levels and Damage
WCCM 2010 164
FEMA
Investor (owner)
choses a performance
level for a given
Earthquake (50-50,20-
50,5-50)
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Element Perfomance Levels
WCCM 2010 165
Generalized force-deformation relation for
steel elements or components
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Capacity and Demand Spectra (ADRS)
WCCM 2010 166
Capacity Spectrum
Demand Spectrum
T=0.5
T=1.0
T=1.5
T=2.0
[mm]
1002.000987.000972.000957.000942.000927.000912.000897.000882.000867.000852.000837.000822.000807.000792.000777.000762.000747.000732.000717.000702.000687.000672.000657.000642.000627.000612.000597.000582.000567.000552.000537.000522.000507.000492.000477.000462.000447.000432.000417.000402.000387.000372.000357.000342.000327.000312.000297.000282.000267.000252.000237.000222.000207.000192.000177.000162.000147.000132.000117.000102.000
87.00072.00057.00042.00027.00012.0000.000-10.000
1.30
1.20
1.10
1.00
0.900
0.800
0.700
0.600
0.500
0.400
0.300
0.200
0.100
0.0
SRa = 0.760
SRv = 0.816
2.5Ca 2.5Ca*SRa
Cv/T
SRv*Cv/
TPerformance
point
IO LSC
P
Sd(T)
Sa(T)
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Two-Dimensional 8-Storey Frame
WCCM 2010 167
H=8x3m
L=3x4m
S 235 Column HEA 240
Beam IPE 240
ag=4.5m/s²
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Plastic Hinges
WCCM 2010 168
• Properties according to FEMA (Table 5-6)
My
u [mrad]
30.00028.00026.00024.00022.00020.00018.00016.00014.00012.00010.0008.0006.0004.0002.0000.000
-30.000-28.000-26.000-24.000-22.000-20.000-18.000-16.000-14.000-12.000-10.000-8.000-6.000-4.000-2.0000.000
[kNm]
160.00
140.00
120.00
100.00
80.00
60.00
40.00
20.00
0.00
-160.00
-140.00
-120.00
-100.00
-80.00
-60.00
-40.00
-20.00
0.00
My
u [mrad]
56.00054.00052.00050.00048.00046.00044.00042.00040.00038.00036.00034.00032.00030.00028.00026.00024.00022.00020.00018.00016.00014.00012.00010.0008.0006.0004.0002.0000.000
-56.000-54.000-52.000-50.000-48.000-46.000-44.000-42.000-40.000-38.000-36.000-34.000-32.000-30.000-28.000-26.000-24.000-22.000-20.000-18.000-16.000-14.000-12.000-10.000-8.000-6.000-4.000-2.000
[kNm]
80.00
70.00
60.00
50.00
40.00
30.00
20.00
10.00
0.00
-80.00
-70.00
-60.00
-50.00
-40.00
-30.00
-20.00
-10.00
0.00
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Force-Controlled Pushover
WCCM 2010 169
T1=1.8 Hz, modal mass=81%M 1 : 162
XY
Z
0.585 0.585
0.5540.554
0.507 0.507
0.442 0.442
0.3600.360
0.293 0.293
0.2770.277
0.267 0.267
0.2530.253
0.221 0.221
0.1800.180
0.165 0.165
0.1330.133
0.083 0.083
0.067 0.067 0.0340.034
Nodal load (f orce) v ector, Loadcase 911 , 1 cm 3D = 0.418 kN (Max=0.585) (total: 8.84)
m-10.00 -5.00 0.00 5.00 10.00 15.00 20.00 25.000.00
-5.00
-10.00
-15.00
-20.00Load patern
according
to the first natural
mode
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Capacity and demand spectra
WCCM 2010 170
Capacity Spectrum
Demand Spectrum
T=0.5
T=1.0
T=1.5
T=2.0
[mm]
1002.000987.000972.000957.000942.000927.000912.000897.000882.000867.000852.000837.000822.000807.000792.000777.000762.000747.000732.000717.000702.000687.000672.000657.000642.000627.000612.000597.000582.000567.000552.000537.000522.000507.000492.000477.000462.000447.000432.000417.000402.000387.000372.000357.000342.000327.000312.000297.000282.000267.000252.000237.000222.000207.000192.000177.000162.000147.000132.000117.000102.000
87.00072.00057.00042.00027.00012.0000.000-10.000
1.30
1.20
1.10
1.00
0.900
0.800
0.700
0.600
0.500
0.400
0.300
0.200
0.100
0.0
SRa = 0.760
SRv = 0.8162.5Ca 2.5Ca*SRa
Cv/T
SRv*Cv/
TPerformance
point
IO LSC
P
![Page 171: Industrial Applications of Computational Mechanics …Katz_10/ Computational Dynamics 2 Basic Possibilities • We may select a solution either • in the time domain • in the frequency](https://reader034.vdocuments.us/reader034/viewer/2022050307/5f6feb806d68146732114160/html5/thumbnails/171.jpg)
171Wissensforum
2011
M 1 : 159XY
Z
Structure
m-10.00 -5.00 0.00 5.00 10.00 15.00 20.000.00
-5.00
-10.00
-15.00
-20.00
M 1 : 165XY
Z
0.115 0.115 0.1150.115
0.107 0.1070.107 0.107
0.09790.0976 0.0976 0.0973
0.0917 0.09160.0875 0.0874
0.08500.0848 0.0846 0.0843
0.06890.0687 0.0684 0.0682
0.04940.0492 0.0489 0.0487
0.02640.0264 0.0260 0.0259
0.0017 0.0015 0.00140.0012
Beam Elements , Implicit hinge reaction Bending moment My Total rotation in mrad, nonlinear Loadcase 100 Modal acceleration
0.00 (Min=-0.115) (Max=0.115)
m-10.00 -5.00 0.00 5.00 10.00 15.00 20.00 25.000.00
-5.00
-10.00
-15.00
-20.00
LC 01
Capacity Spectrum
Demand Spectrum
T=0.5
T=1.0
T=1.5
T=2.0
[mm]
1002.000987.000972.000957.000942.000927.000912.000897.000882.000867.000852.000837.000822.000807.000792.000777.000762.000747.000732.000717.000702.000687.000672.000657.000642.000627.000612.000597.000582.000567.000552.000537.000522.000507.000492.000477.000462.000447.000432.000417.000402.000387.000372.000357.000342.000327.000312.000297.000282.000267.000252.000237.000222.000207.000192.000177.000162.000147.000132.000117.000102.000
87.00072.00057.00042.00027.00012.0000.000-10.000
1.30
1.20
1.10
1.00
0.900
0.800
0.700
0.600
0.500
0.400
0.300
0.200
0.100
0.0
My
u [mrad]
30.00028.00026.00024.00022.00020.00018.00016.00014.00012.00010.0008.0006.0004.0002.0000.000
-30.000-28.000-26.000-24.000-22.000-20.000-18.000-16.000-14.000-12.000-10.000-8.000-6.000-4.000-2.0000.000
[kNm]
160.00
140.00
120.00
100.00
80.00
60.00
40.00
20.00
0.00
-160.00
-140.00
-120.00
-100.00
-80.00
-60.00
-40.00
-20.00
0.00
column
My
u [mrad]
56.00054.00052.00050.00048.00046.00044.00042.00040.00038.00036.00034.00032.00030.00028.00026.00024.00022.00020.00018.00016.00014.00012.00010.0008.0006.0004.0002.0000.000
-56.000-54.000-52.000-50.000-48.000-46.000-44.000-42.000-40.000-38.000-36.000-34.000-32.000-30.000-28.000-26.000-24.000-22.000-20.000-18.000-16.000-14.000-12.000-10.000-8.000-6.000-4.000-2.000
[kNm]
80.00
70.00
60.00
50.00
40.00
30.00
20.00
10.00
0.00
-80.00
-70.00
-60.00
-50.00
-40.00
-30.00
-20.00
-10.00
0.00
beam
![Page 172: Industrial Applications of Computational Mechanics …Katz_10/ Computational Dynamics 2 Basic Possibilities • We may select a solution either • in the time domain • in the frequency](https://reader034.vdocuments.us/reader034/viewer/2022050307/5f6feb806d68146732114160/html5/thumbnails/172.jpg)
172Wissensforum
2011
M 1 : 159XY
Z
Structure
m-10.00 -5.00 0.00 5.00 10.00 15.00 20.000.00
-5.00
-10.00
-15.00
-20.00
M 1 : 165XY
Z
4.81 4.71
4.65
4.57
4.52
4.47
4.41 4.33
4.23 4.18
4.16 3.99
3.97
3.94
3.92
3.87
3.46 3.28 3.273.23
3.21 3.212.99 2.99
2.64 2.51 2.48 2.43
1.81 1.72 1.71 1.58
0.984 0.844 0.842 0.809
Beam Elements , Implicit hinge reaction Bending moment My Total rotation in mrad, nonlinear Loadcase 119 Modal acceleration
-2.15 (Min=-4.81) (Max=4.71)
m-10.00 -5.00 0.00 5.00 10.00 15.00 20.00 25.000.00
-5.00
-10.00
-15.00
-20.00
LC 19
Capacity Spectrum
Demand Spectrum
T=0.5
T=1.0
T=1.5
T=2.0
[mm]
1002.000987.000972.000957.000942.000927.000912.000897.000882.000867.000852.000837.000822.000807.000792.000777.000762.000747.000732.000717.000702.000687.000672.000657.000642.000627.000612.000597.000582.000567.000552.000537.000522.000507.000492.000477.000462.000447.000432.000417.000402.000387.000372.000357.000342.000327.000312.000297.000282.000267.000252.000237.000222.000207.000192.000177.000162.000147.000132.000117.000102.000
87.00072.00057.00042.00027.00012.0000.000-10.000
1.30
1.20
1.10
1.00
0.900
0.800
0.700
0.600
0.500
0.400
0.300
0.200
0.100
0.0
My
u [mrad]
30.00028.00026.00024.00022.00020.00018.00016.00014.00012.00010.0008.0006.0004.0002.0000.000
-30.000-28.000-26.000-24.000-22.000-20.000-18.000-16.000-14.000-12.000-10.000-8.000-6.000-4.000-2.0000.000
[kNm]
160.00
140.00
120.00
100.00
80.00
60.00
40.00
20.00
0.00
-160.00
-140.00
-120.00
-100.00
-80.00
-60.00
-40.00
-20.00
0.00
column
My
u [mrad]
56.00054.00052.00050.00048.00046.00044.00042.00040.00038.00036.00034.00032.00030.00028.00026.00024.00022.00020.00018.00016.00014.00012.00010.0008.0006.0004.0002.0000.000
-56.000-54.000-52.000-50.000-48.000-46.000-44.000-42.000-40.000-38.000-36.000-34.000-32.000-30.000-28.000-26.000-24.000-22.000-20.000-18.000-16.000-14.000-12.000-10.000-8.000-6.000-4.000-2.000
[kNm]
80.00
70.00
60.00
50.00
40.00
30.00
20.00
10.00
0.00
-80.00
-70.00
-60.00
-50.00
-40.00
-30.00
-20.00
-10.00
0.00
beam
![Page 173: Industrial Applications of Computational Mechanics …Katz_10/ Computational Dynamics 2 Basic Possibilities • We may select a solution either • in the time domain • in the frequency](https://reader034.vdocuments.us/reader034/viewer/2022050307/5f6feb806d68146732114160/html5/thumbnails/173.jpg)
M 1 : 165XY
Z
5.23 4.97
4.90
4.79
4.76
4.71
4.65 4.56
4.45 4.40
4.37 4.20
4.18
4.15
4.13
4.08
3.64 3.45 3.443.40
3.38 3.383.15 3.15
2.78 2.64 2.61 2.56
1.90 1.81 1.80 1.67
1.03 0.8860.883 0.856
Beam Elements , Implicit hinge reaction Bending moment My Total rotation in mrad, nonlinear Loadcase 120 Modal acceleration
-2.26 (Min=-5.23) (Max=4.97)
m-10.00 -5.00 0.00 5.00 10.00 15.00 20.00 25.000.00
-5.00
-10.00
-15.00
-20.00
M 1 : 159XY
Z
80.1
Beam Elements , Implicit hinge reaction Bending moment My nonlinear in kNm, nonlinear Loadcase 120 Modal acceleration -2.26
(Min=-80.1) (Max=-80.1)
m-10.00 -5.00 0.00 5.00 10.00 15.00 20.000.00
-5.00
-10.00
-15.00
-20.00
173Wissensforum
2011
LC 20
Capacity Spectrum
Demand Spectrum
T=0.5
T=1.0
T=1.5
T=2.0
[mm]
1002.000987.000972.000957.000942.000927.000912.000897.000882.000867.000852.000837.000822.000807.000792.000777.000762.000747.000732.000717.000702.000687.000672.000657.000642.000627.000612.000597.000582.000567.000552.000537.000522.000507.000492.000477.000462.000447.000432.000417.000402.000387.000372.000357.000342.000327.000312.000297.000282.000267.000252.000237.000222.000207.000192.000177.000162.000147.000132.000117.000102.000
87.00072.00057.00042.00027.00012.0000.000-10.000
1.30
1.20
1.10
1.00
0.900
0.800
0.700
0.600
0.500
0.400
0.300
0.200
0.100
0.0
My
u [mrad]
30.00028.00026.00024.00022.00020.00018.00016.00014.00012.00010.0008.0006.0004.0002.0000.000
-30.000-28.000-26.000-24.000-22.000-20.000-18.000-16.000-14.000-12.000-10.000-8.000-6.000-4.000-2.0000.000
[kNm]
160.00
140.00
120.00
100.00
80.00
60.00
40.00
20.00
0.00
-160.00
-140.00
-120.00
-100.00
-80.00
-60.00
-40.00
-20.00
0.00
column
My
u [mrad]
56.00054.00052.00050.00048.00046.00044.00042.00040.00038.00036.00034.00032.00030.00028.00026.00024.00022.00020.00018.00016.00014.00012.00010.0008.0006.0004.0002.0000.000
-56.000-54.000-52.000-50.000-48.000-46.000-44.000-42.000-40.000-38.000-36.000-34.000-32.000-30.000-28.000-26.000-24.000-22.000-20.000-18.000-16.000-14.000-12.000-10.000-8.000-6.000-4.000-2.000
[kNm]
80.00
70.00
60.00
50.00
40.00
30.00
20.00
10.00
0.00
-80.00
-70.00
-60.00
-50.00
-40.00
-30.00
-20.00
-10.00
0.00
beam
![Page 174: Industrial Applications of Computational Mechanics …Katz_10/ Computational Dynamics 2 Basic Possibilities • We may select a solution either • in the time domain • in the frequency](https://reader034.vdocuments.us/reader034/viewer/2022050307/5f6feb806d68146732114160/html5/thumbnails/174.jpg)
M 1 : 159XY
Z
80.6 80.5
80.3 80.1
80.080.0
Beam Elements , Implicit hinge reaction Bending moment My nonlinear in kNm, nonlinear Loadcase 121 Modal acceleration -2.38
(Min=-80.6) (Max=80.5)
m-10.00 -5.00 0.00 5.00 10.00 15.00 20.00 25.000.00
-5.00
-10.00
-15.00
-20.00
M 1 : 165XY
Z
6.29 5.96
5.61 5.15
5.035.02
4.87 4.83
4.70 4.65
4.60 4.43
4.42
4.37
4.36
4.30
3.82 3.62 3.623.58
3.56 3.553.32 3.31
2.91 2.76 2.74 2.70
1.99 1.89 1.89 1.76
1.08 0.9280.924 0.904
Beam Elements , Implicit hinge reaction Bending moment My Total rotation in mrad, nonlinear Loadcase 121 Modal acceleration
-2.38 (Min=-6.29) (Max=5.96)
m-10.00 -5.00 0.00 5.00 10.00 15.00 20.00 25.000.00
-5.00
-10.00
-15.00
-20.00
174Wissensforum
2011
Capacity Spectrum
Demand Spectrum
T=0.5
T=1.0
T=1.5
T=2.0
[mm]
1002.000987.000972.000957.000942.000927.000912.000897.000882.000867.000852.000837.000822.000807.000792.000777.000762.000747.000732.000717.000702.000687.000672.000657.000642.000627.000612.000597.000582.000567.000552.000537.000522.000507.000492.000477.000462.000447.000432.000417.000402.000387.000372.000357.000342.000327.000312.000297.000282.000267.000252.000237.000222.000207.000192.000177.000162.000147.000132.000117.000102.000
87.00072.00057.00042.00027.00012.0000.000-10.000
1.30
1.20
1.10
1.00
0.900
0.800
0.700
0.600
0.500
0.400
0.300
0.200
0.100
0.0
LC 21
My
u [mrad]
30.00028.00026.00024.00022.00020.00018.00016.00014.00012.00010.0008.0006.0004.0002.0000.000
-30.000-28.000-26.000-24.000-22.000-20.000-18.000-16.000-14.000-12.000-10.000-8.000-6.000-4.000-2.0000.000
[kNm]
160.00
140.00
120.00
100.00
80.00
60.00
40.00
20.00
0.00
-160.00
-140.00
-120.00
-100.00
-80.00
-60.00
-40.00
-20.00
0.00
column
My
u [mrad]
56.00054.00052.00050.00048.00046.00044.00042.00040.00038.00036.00034.00032.00030.00028.00026.00024.00022.00020.00018.00016.00014.00012.00010.0008.0006.0004.0002.0000.000
-56.000-54.000-52.000-50.000-48.000-46.000-44.000-42.000-40.000-38.000-36.000-34.000-32.000-30.000-28.000-26.000-24.000-22.000-20.000-18.000-16.000-14.000-12.000-10.000-8.000-6.000-4.000-2.000
[kNm]
80.00
70.00
60.00
50.00
40.00
30.00
20.00
10.00
0.00
-80.00
-70.00
-60.00
-50.00
-40.00
-30.00
-20.00
-10.00
0.00
beam
![Page 175: Industrial Applications of Computational Mechanics …Katz_10/ Computational Dynamics 2 Basic Possibilities • We may select a solution either • in the time domain • in the frequency](https://reader034.vdocuments.us/reader034/viewer/2022050307/5f6feb806d68146732114160/html5/thumbnails/175.jpg)
M 1 : 165XY
Z
7.71 7.46
7.08 6.71
6.486.48
5.81 5.80
5.11 4.98
4.90 4.74
4.72 4.68
4.66 4.58
4.02 3.833.82 3.77
3.77 3.763.51 3.51
3.06 2.90 2.88 2.84
2.08 1.981.98 1.85
1.13 0.9710.965 0.952
Beam Elements , Implicit hinge reaction Bending moment My Total rotation in mrad, nonlinear Loadcase 122 Modal acceleration
-2.49 (Min=-7.71) (Max=7.46)
m-10.00 -5.00 0.00 5.00 10.00 15.00 20.00 25.000.00
-5.00
-10.00
-15.00
-20.00
M 1 : 159XY
Z
81.3 81.2
81.0 80.8
80.780.7
80.4 80.4
80.1
Beam Elements , Implicit hinge reaction Bending moment My nonlinear in kNm, nonlinear Loadcase 122 Modal acceleration -2.49
(Min=-81.3) (Max=81.2)
m-10.00 -5.00 0.00 5.00 10.00 15.00 20.00 25.000.00
-5.00
-10.00
-15.00
-20.00
175Wissensforum
2011
LC 22
Capacity Spectrum
Demand Spectrum
T=0.5
T=1.0
T=1.5
T=2.0
[mm]
1002.000987.000972.000957.000942.000927.000912.000897.000882.000867.000852.000837.000822.000807.000792.000777.000762.000747.000732.000717.000702.000687.000672.000657.000642.000627.000612.000597.000582.000567.000552.000537.000522.000507.000492.000477.000462.000447.000432.000417.000402.000387.000372.000357.000342.000327.000312.000297.000282.000267.000252.000237.000222.000207.000192.000177.000162.000147.000132.000117.000102.000
87.00072.00057.00042.00027.00012.0000.000-10.000
1.30
1.20
1.10
1.00
0.900
0.800
0.700
0.600
0.500
0.400
0.300
0.200
0.100
0.0
My
u [mrad]
30.00028.00026.00024.00022.00020.00018.00016.00014.00012.00010.0008.0006.0004.0002.0000.000
-30.000-28.000-26.000-24.000-22.000-20.000-18.000-16.000-14.000-12.000-10.000-8.000-6.000-4.000-2.0000.000
[kNm]
160.00
140.00
120.00
100.00
80.00
60.00
40.00
20.00
0.00
-160.00
-140.00
-120.00
-100.00
-80.00
-60.00
-40.00
-20.00
0.00
column
My
u [mrad]
56.00054.00052.00050.00048.00046.00044.00042.00040.00038.00036.00034.00032.00030.00028.00026.00024.00022.00020.00018.00016.00014.00012.00010.0008.0006.0004.0002.0000.000
-56.000-54.000-52.000-50.000-48.000-46.000-44.000-42.000-40.000-38.000-36.000-34.000-32.000-30.000-28.000-26.000-24.000-22.000-20.000-18.000-16.000-14.000-12.000-10.000-8.000-6.000-4.000-2.000
[kNm]
80.00
70.00
60.00
50.00
40.00
30.00
20.00
10.00
0.00
-80.00
-70.00
-60.00
-50.00
-40.00
-30.00
-20.00
-10.00
0.00
beam
![Page 176: Industrial Applications of Computational Mechanics …Katz_10/ Computational Dynamics 2 Basic Possibilities • We may select a solution either • in the time domain • in the frequency](https://reader034.vdocuments.us/reader034/viewer/2022050307/5f6feb806d68146732114160/html5/thumbnails/176.jpg)
M 1 : 165XY
Z
9.62 9.37
8.91 8.56
8.428.42
7.67 7.67
6.66 6.50
6.12 5.55
5.05 5.04
4.984.97
4.26 4.074.05
4.05 4.05
4.00
3.74 3.74
3.21 3.04 3.02 2.99
2.18 2.082.07 1.95
1.18 1.011.01 1.00
Beam Elements , Implicit hinge reaction Bending moment My Total rotation in mrad, nonlinear Loadcase 123 Modal acceleration
-2.60 (Min=-9.62) (Max=9.37)
m-10.00 -5.00 0.00 5.00 10.00 15.00 20.00 25.000.00
-5.00
-10.00
-15.00
-20.00
M 1 : 159XY
Z
82.2 82.1
81.9 81.7
81.681.6
81.3 81.3
80.8 80.7
80.5 80.3
80.0 80.0
Beam Elements , Implicit hinge reaction Bending moment My nonlinear in kNm, nonlinear Loadcase 123 Modal acceleration -2.60
(Min=-82.2) (Max=82.1)
m-10.00 -5.00 0.00 5.00 10.00 15.00 20.00 25.000.00
-5.00
-10.00
-15.00
-20.00
176Wissensforum
2011
LC 23
Capacity Spectrum
Demand Spectrum
T=0.5
T=1.0
T=1.5
T=2.0
[mm]
1002.000987.000972.000957.000942.000927.000912.000897.000882.000867.000852.000837.000822.000807.000792.000777.000762.000747.000732.000717.000702.000687.000672.000657.000642.000627.000612.000597.000582.000567.000552.000537.000522.000507.000492.000477.000462.000447.000432.000417.000402.000387.000372.000357.000342.000327.000312.000297.000282.000267.000252.000237.000222.000207.000192.000177.000162.000147.000132.000117.000102.000
87.00072.00057.00042.00027.00012.0000.000-10.000
1.30
1.20
1.10
1.00
0.900
0.800
0.700
0.600
0.500
0.400
0.300
0.200
0.100
0.0
My
u [mrad]
30.00028.00026.00024.00022.00020.00018.00016.00014.00012.00010.0008.0006.0004.0002.0000.000
-30.000-28.000-26.000-24.000-22.000-20.000-18.000-16.000-14.000-12.000-10.000-8.000-6.000-4.000-2.0000.000
[kNm]
160.00
140.00
120.00
100.00
80.00
60.00
40.00
20.00
0.00
-160.00
-140.00
-120.00
-100.00
-80.00
-60.00
-40.00
-20.00
0.00
column
My
u [mrad]
56.00054.00052.00050.00048.00046.00044.00042.00040.00038.00036.00034.00032.00030.00028.00026.00024.00022.00020.00018.00016.00014.00012.00010.0008.0006.0004.0002.0000.000
-56.000-54.000-52.000-50.000-48.000-46.000-44.000-42.000-40.000-38.000-36.000-34.000-32.000-30.000-28.000-26.000-24.000-22.000-20.000-18.000-16.000-14.000-12.000-10.000-8.000-6.000-4.000-2.000
[kNm]
80.00
70.00
60.00
50.00
40.00
30.00
20.00
10.00
0.00
-80.00
-70.00
-60.00
-50.00
-40.00
-30.00
-20.00
-10.00
0.00
beam
![Page 177: Industrial Applications of Computational Mechanics …Katz_10/ Computational Dynamics 2 Basic Possibilities • We may select a solution either • in the time domain • in the frequency](https://reader034.vdocuments.us/reader034/viewer/2022050307/5f6feb806d68146732114160/html5/thumbnails/177.jpg)
M 1 : 165XY
Z
12.4 12.1
11.6 11.3
11.211.2
10.410.4
8.68 8.54
8.20 7.75
7.05 7.04
6.95 6.94
4.64 4.44
4.44 4.44
4.40 4.35
4.13 4.13
3.40 3.22 3.20 3.18
2.28 2.182.17 2.05
1.23 1.06 1.051.05
Beam Elements , Implicit hinge reaction Bending moment My Total rotation in mrad, nonlinear Loadcase 124 Modal acceleration
-2.72 (Min=-12.4) (Max=12.1)
m-10.00 -5.00 0.00 5.00 10.00 15.00 20.00 25.000.00
-5.00
-10.00
-15.00
-20.00
M 1 : 159XY
Z
83.5 83.4
83.2 83.0
83.083.0
82.682.6
81.8 81.7
81.5 81.3
81.0 81.0
80.9 80.9
Beam Elements , Implicit hinge reaction Bending moment My nonlinear in kNm, nonlinear Loadcase 124 Modal acceleration -2.72
(Min=-83.5) (Max=83.4)
m-10.00 -5.00 0.00 5.00 10.00 15.00 20.00 25.000.00
-5.00
-10.00
-15.00
-20.00
177Wissensforum
2011
LC 24
Capacity Spectrum
Demand Spectrum
T=0.5
T=1.0
T=1.5
T=2.0
[mm]
1002.000987.000972.000957.000942.000927.000912.000897.000882.000867.000852.000837.000822.000807.000792.000777.000762.000747.000732.000717.000702.000687.000672.000657.000642.000627.000612.000597.000582.000567.000552.000537.000522.000507.000492.000477.000462.000447.000432.000417.000402.000387.000372.000357.000342.000327.000312.000297.000282.000267.000252.000237.000222.000207.000192.000177.000162.000147.000132.000117.000102.000
87.00072.00057.00042.00027.00012.0000.000-10.000
1.30
1.20
1.10
1.00
0.900
0.800
0.700
0.600
0.500
0.400
0.300
0.200
0.100
0.0
My
u [mrad]
30.00028.00026.00024.00022.00020.00018.00016.00014.00012.00010.0008.0006.0004.0002.0000.000
-30.000-28.000-26.000-24.000-22.000-20.000-18.000-16.000-14.000-12.000-10.000-8.000-6.000-4.000-2.0000.000
[kNm]
160.00
140.00
120.00
100.00
80.00
60.00
40.00
20.00
0.00
-160.00
-140.00
-120.00
-100.00
-80.00
-60.00
-40.00
-20.00
0.00
column
My
u [mrad]
56.00054.00052.00050.00048.00046.00044.00042.00040.00038.00036.00034.00032.00030.00028.00026.00024.00022.00020.00018.00016.00014.00012.00010.0008.0006.0004.0002.0000.000
-56.000-54.000-52.000-50.000-48.000-46.000-44.000-42.000-40.000-38.000-36.000-34.000-32.000-30.000-28.000-26.000-24.000-22.000-20.000-18.000-16.000-14.000-12.000-10.000-8.000-6.000-4.000-2.000
[kNm]
80.00
70.00
60.00
50.00
40.00
30.00
20.00
10.00
0.00
-80.00
-70.00
-60.00
-50.00
-40.00
-30.00
-20.00
-10.00
0.00
beam
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M 1 : 165XY
Z
15.2 14.9
14.5 14.1
14.014.0
13.213.2
10.7 10.6
10.4 9.919.13 9.12
9.09 9.08
5.12
4.84 4.84
4.844.76 4.71
4.53 4.53
3.59 3.41 3.39 3.37
2.39 2.292.28 2.16
1.28 1.11 1.111.10
Beam Elements , Implicit hinge reaction Bending moment My Total rotation in mrad, nonlinear Loadcase 125 Modal acceleration
-2.83 (Min=-15.2) (Max=14.9)
m-10.00 -5.00 0.00 5.00 10.00 15.00 20.00 25.000.00
-5.00
-10.00
-15.00
-20.00
M 1 : 159XY
Z
84.9 84.8
84.5 84.4
84.384.3
83.983.9
82.8 82.7
82.6 82.482.0 82.0
82.0 82.0
80.1
Beam Elements , Implicit hinge reaction Bending moment My nonlinear in kNm, nonlinear Loadcase 125 Modal acceleration -2.83
(Min=-84.9) (Max=84.8)
m-10.00 -5.00 0.00 5.00 10.00 15.00 20.00 25.000.00
-5.00
-10.00
-15.00
-20.00
178Wissensforum
2011
LC 25
Capacity Spectrum
Demand Spectrum
T=0.5
T=1.0
T=1.5
T=2.0
[mm]
1002.000987.000972.000957.000942.000927.000912.000897.000882.000867.000852.000837.000822.000807.000792.000777.000762.000747.000732.000717.000702.000687.000672.000657.000642.000627.000612.000597.000582.000567.000552.000537.000522.000507.000492.000477.000462.000447.000432.000417.000402.000387.000372.000357.000342.000327.000312.000297.000282.000267.000252.000237.000222.000207.000192.000177.000162.000147.000132.000117.000102.000
87.00072.00057.00042.00027.00012.0000.000-10.000
1.30
1.20
1.10
1.00
0.900
0.800
0.700
0.600
0.500
0.400
0.300
0.200
0.100
0.0
My
u [mrad]
30.00028.00026.00024.00022.00020.00018.00016.00014.00012.00010.0008.0006.0004.0002.0000.000
-30.000-28.000-26.000-24.000-22.000-20.000-18.000-16.000-14.000-12.000-10.000-8.000-6.000-4.000-2.0000.000
[kNm]
160.00
140.00
120.00
100.00
80.00
60.00
40.00
20.00
0.00
-160.00
-140.00
-120.00
-100.00
-80.00
-60.00
-40.00
-20.00
0.00
column
My
u [mrad]
56.00054.00052.00050.00048.00046.00044.00042.00040.00038.00036.00034.00032.00030.00028.00026.00024.00022.00020.00018.00016.00014.00012.00010.0008.0006.0004.0002.0000.000
-56.000-54.000-52.000-50.000-48.000-46.000-44.000-42.000-40.000-38.000-36.000-34.000-32.000-30.000-28.000-26.000-24.000-22.000-20.000-18.000-16.000-14.000-12.000-10.000-8.000-6.000-4.000-2.000
[kNm]
80.00
70.00
60.00
50.00
40.00
30.00
20.00
10.00
0.00
-80.00
-70.00
-60.00
-50.00
-40.00
-30.00
-20.00
-10.00
0.00
beam
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M 1 : 165XY
Z
18.6 18.4
17.9 17.5
17.417.4
16.616.6
13.6 13.5
13.0 12.6
11.9 11.8
11.811.8
6.97
6.63 6.63
6.44
5.76 5.76
5.70 5.69
3.86 3.66 3.65 3.64
2.52 2.412.40 2.29
1.35 1.171.161.15
Beam Elements , Implicit hinge reaction Bending moment My Total rotation in mrad, nonlinear Loadcase 126 Modal acceleration
-2.94 (Min=-18.6) (Max=18.4)
m-10.00 -5.00 0.00 5.00 10.00 15.00 20.00 25.000.00
-5.00
-10.00
-15.00
-20.00
M 1 : 159XY
Z
161.6
86.5
161.6160.7 160.7
86.4
86.2 86.0
86.086.0
85.585.5
84.1 84.1
83.9 83.6
83.3 83.3
83.383.3
80.9 80.780.3 80.3
Beam Elements , Implicit hinge reaction Bending moment My nonlinear in kNm, nonlinear Loadcase 126 Modal acceleration -2.94
(Min=-86.5) (Max=161.6)
m-10.00 -5.00 0.00 5.00 10.00 15.00 20.00 25.000.00
-5.00
-10.00
-15.00
-20.00
179Wissensforum
2011
LC 26
Capacity Spectrum
Demand Spectrum
T=0.5
T=1.0
T=1.5
T=2.0
[mm]
1002.000987.000972.000957.000942.000927.000912.000897.000882.000867.000852.000837.000822.000807.000792.000777.000762.000747.000732.000717.000702.000687.000672.000657.000642.000627.000612.000597.000582.000567.000552.000537.000522.000507.000492.000477.000462.000447.000432.000417.000402.000387.000372.000357.000342.000327.000312.000297.000282.000267.000252.000237.000222.000207.000192.000177.000162.000147.000132.000117.000102.000
87.00072.00057.00042.00027.00012.0000.000-10.000
1.30
1.20
1.10
1.00
0.900
0.800
0.700
0.600
0.500
0.400
0.300
0.200
0.100
0.0
My
u [mrad]
30.00028.00026.00024.00022.00020.00018.00016.00014.00012.00010.0008.0006.0004.0002.0000.000
-30.000-28.000-26.000-24.000-22.000-20.000-18.000-16.000-14.000-12.000-10.000-8.000-6.000-4.000-2.0000.000
[kNm]
160.00
140.00
120.00
100.00
80.00
60.00
40.00
20.00
0.00
-160.00
-140.00
-120.00
-100.00
-80.00
-60.00
-40.00
-20.00
0.00
column
My
u [mrad]
56.00054.00052.00050.00048.00046.00044.00042.00040.00038.00036.00034.00032.00030.00028.00026.00024.00022.00020.00018.00016.00014.00012.00010.0008.0006.0004.0002.0000.000
-56.000-54.000-52.000-50.000-48.000-46.000-44.000-42.000-40.000-38.000-36.000-34.000-32.000-30.000-28.000-26.000-24.000-22.000-20.000-18.000-16.000-14.000-12.000-10.000-8.000-6.000-4.000-2.000
[kNm]
80.00
70.00
60.00
50.00
40.00
30.00
20.00
10.00
0.00
-80.00
-70.00
-60.00
-50.00
-40.00
-30.00
-20.00
-10.00
0.00
beam
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M 1 : 165XY
Z
24.1 23.922.922.9
22.8 22.521.521.5
19.3 19.117.4 17.4
17.0 16.615.815.8
12.1 12.111.2 11.2
9.64 9.118.40 8.39
4.28 4.074.06 4.04
2.69 2.582.57 2.46
1.42 1.241.231.21
Beam Elements , Implicit hinge reaction Bending moment My Total rotation in mrad, nonlinear Loadcase 127 Modal acceleration
-3.05 (Min=-24.1) (Max=23.9)
m-10.00 -5.00 0.00 5.00 10.00 15.00 20.00 25.000.00
-5.00
-10.00
-15.00
-20.00
M 1 : 159XY
Z
166.8
89.2
166.8166.0 166.0
89.188.688.6
88.5 88.487.987.9
86.8 86.886.0 86.0
85.8 85.685.285.2
82.2 82.081.6 81.6
Beam Elements , Implicit hinge reaction Bending moment My nonlinear in kNm, nonlinear Loadcase 127 Modal acceleration -3.05
(Min=-89.2) (Max=166.8)
m-10.00 -5.00 0.00 5.00 10.00 15.00 20.00 25.000.00
-5.00
-10.00
-15.00
-20.00
180Wissensforum
2011
LC 27
Capacity Spectrum
Demand Spectrum
T=0.5
T=1.0
T=1.5
T=2.0
[mm]
1002.000987.000972.000957.000942.000927.000912.000897.000882.000867.000852.000837.000822.000807.000792.000777.000762.000747.000732.000717.000702.000687.000672.000657.000642.000627.000612.000597.000582.000567.000552.000537.000522.000507.000492.000477.000462.000447.000432.000417.000402.000387.000372.000357.000342.000327.000312.000297.000282.000267.000252.000237.000222.000207.000192.000177.000162.000147.000132.000117.000102.000
87.00072.00057.00042.00027.00012.0000.000-10.000
1.30
1.20
1.10
1.00
0.900
0.800
0.700
0.600
0.500
0.400
0.300
0.200
0.100
0.0
My
u [mrad]
30.00028.00026.00024.00022.00020.00018.00016.00014.00012.00010.0008.0006.0004.0002.0000.000
-30.000-28.000-26.000-24.000-22.000-20.000-18.000-16.000-14.000-12.000-10.000-8.000-6.000-4.000-2.0000.000
[kNm]
160.00
140.00
120.00
100.00
80.00
60.00
40.00
20.00
0.00
-160.00
-140.00
-120.00
-100.00
-80.00
-60.00
-40.00
-20.00
0.00
column
My
u [mrad]
56.00054.00052.00050.00048.00046.00044.00042.00040.00038.00036.00034.00032.00030.00028.00026.00024.00022.00020.00018.00016.00014.00012.00010.0008.0006.0004.0002.0000.000
-56.000-54.000-52.000-50.000-48.000-46.000-44.000-42.000-40.000-38.000-36.000-34.000-32.000-30.000-28.000-26.000-24.000-22.000-20.000-18.000-16.000-14.000-12.000-10.000-8.000-6.000-4.000-2.000
[kNm]
80.00
70.00
60.00
50.00
40.00
30.00
20.00
10.00
0.00
-80.00
-70.00
-60.00
-50.00
-40.00
-30.00
-20.00
-10.00
0.00
beam
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M 1 : 165XY
Z
29.6 29.328.328.3
27.7 27.426.426.4
24.9 24.723.0 22.9
21.1 20.619.819.8
17.6 17.616.6 16.6
12.3 11.811.1 11.1
4.71 4.504.46 4.44
2.87 2.762.75 2.63
1.50 1.321.301.28
Beam Elements , Implicit hinge reaction Bending moment My Total rotation in mrad, nonlinear Loadcase 128 Modal acceleration
-3.17 (Min=-29.6) (Max=29.3)
m-10.00 -5.00 0.00 5.00 10.00 15.00 20.00 25.000.00
-5.00
-10.00
-15.00
-20.00
M 1 : 159XY
Z
172.1
91.8
172.1171.2 171.2
91.791.291.2
90.9 90.790.390.3
89.5 89.588.6 88.6
87.7 87.587.187.1
83.5 83.282.9 82.9
Beam Elements , Implicit hinge reaction Bending moment My nonlinear in kNm, nonlinear Loadcase 128 Modal acceleration -3.17
(Min=-91.8) (Max=172.1)
m-10.00 -5.00 0.00 5.00 10.00 15.00 20.00 25.000.00
-5.00
-10.00
-15.00
-20.00
181Wissensforum
2011
LC 28
Capacity Spectrum
Demand Spectrum
T=0.5
T=1.0
T=1.5
T=2.0
[mm]
1002.000987.000972.000957.000942.000927.000912.000897.000882.000867.000852.000837.000822.000807.000792.000777.000762.000747.000732.000717.000702.000687.000672.000657.000642.000627.000612.000597.000582.000567.000552.000537.000522.000507.000492.000477.000462.000447.000432.000417.000402.000387.000372.000357.000342.000327.000312.000297.000282.000267.000252.000237.000222.000207.000192.000177.000162.000147.000132.000117.000102.000
87.00072.00057.00042.00027.00012.0000.000-10.000
1.30
1.20
1.10
1.00
0.900
0.800
0.700
0.600
0.500
0.400
0.300
0.200
0.100
0.0
My
u [mrad]
30.00028.00026.00024.00022.00020.00018.00016.00014.00012.00010.0008.0006.0004.0002.0000.000
-30.000-28.000-26.000-24.000-22.000-20.000-18.000-16.000-14.000-12.000-10.000-8.000-6.000-4.000-2.0000.000
[kNm]
160.00
140.00
120.00
100.00
80.00
60.00
40.00
20.00
0.00
-160.00
-140.00
-120.00
-100.00
-80.00
-60.00
-40.00
-20.00
0.00
column
My
u [mrad]
56.00054.00052.00050.00048.00046.00044.00042.00040.00038.00036.00034.00032.00030.00028.00026.00024.00022.00020.00018.00016.00014.00012.00010.0008.0006.0004.0002.0000.000
-56.000-54.000-52.000-50.000-48.000-46.000-44.000-42.000-40.000-38.000-36.000-34.000-32.000-30.000-28.000-26.000-24.000-22.000-20.000-18.000-16.000-14.000-12.000-10.000-8.000-6.000-4.000-2.000
[kNm]
80.00
70.00
60.00
50.00
40.00
30.00
20.00
10.00
0.00
-80.00
-70.00
-60.00
-50.00
-40.00
-30.00
-20.00
-10.00
0.00
beam
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Katz_10/ Computational Dynamics
182
Transient Analysis
• Many (!) artificial or measured earthquake response
• Non linear time integration
• Averaging the results ?
Zeit
[sec] 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0
Beschleunigung AX [m/sec2]
-0.30
-0.20
-0.10
-0.00
0.10
0.20
0.30
0.40
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Katz_10/ Computational Dynamics
183
Floor response spectra
(Deckenantwortspektrum)• If we have the accelerations at a given point in the structure we may then create from
those values a response spectra for that point, to be applied for other components
• This is a replacement of the Transfer-Function of an Analysis in the Frequency
domain
Frequenz
(Hertz) 0.5 1. 2. 5. 10. 20.
Verschiebung [mm]
0.000
20.000
40.000
60.000
80.000
100.000
120.000
140.000
![Page 184: Industrial Applications of Computational Mechanics …Katz_10/ Computational Dynamics 2 Basic Possibilities • We may select a solution either • in the time domain • in the frequency](https://reader034.vdocuments.us/reader034/viewer/2022050307/5f6feb806d68146732114160/html5/thumbnails/184.jpg)
Static Soil Structure Interaction
WCCM 2010 184
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Soil-Structure-Interaction
Katz_10/ Computational Dynamics
185
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Why do we need SSI ?
• Elastic stiffness of soil has an impact on the structure
• Dynamic stiffness (mass + damping) of soil has an
impact on the structure
• Favorable effects (e.g. damping)
• Unfavorable effects (e.g. change of frequency)
• Main applications
• Earthquake
• Dynamic loading (e.g. wind energy systems)
• All kinds of base vibrationsSSI /
186
SOFiSTiK Seminar 2010
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Damping of Foundation
SSI / SOFiSTiK Seminar 2010
187
Frequency [Hz]
Ph
as
e a
ng
le ≈
Da
mp
ing
in
%
*H. Sadegh-Azar et al., Bautechnik, 86, 2009
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Hanshin Expressway in Kobe
WCCM 2010 188
μcapacity = 2 - 3
Without SSI*
Tfixed = 0.84s
ξfixed = 5 %
μfixed = 3
With SSI*
TSSI = 1.04s
ξSSI = 9.8 %
μSSI = 4.7
* G. Mylonakis et al. (2006), EESD
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The range of possible methods for SSI
WCCM 2010 189
External
loads
Non-reflecting
(transmitting)
boundary conditions
simplified direct method substructure
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Non reflective Boundary Conditions
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t
P(t)/P0
1.0
0.0125
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Effect of Boundary Conditions
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t
P(t)/P0
1.0
0.0125
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Substructure Methods
• Boundary Elements (most general solution)
• Thin Layer Elements
• SBFEM = Scaled Boundary Finite Elements
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192
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0
( ) ( ) ( )
t
t t t d = −b br M u
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Why SBFEM (J.P. Wolf / Song 1996)
• Best compromise between numerical effort and modelling
possibilities
• Sound coupling to existing FEM code
• Solution in 2D and in 3D possible
• Drawbacks
• Fully populated matrices of interface
• Convolution Integral
• Numerical instabilities
• Total effort may become quite large
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Example 1
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194
E = 200 GPa
ν = 0.30
γ = 0.0
A BOP(t)
scaled boundary finite-elements
P(t)/P0
cs = 100 m/s
ν = 0.25
ρ = 2.0 t/m3
viscous
boundary
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Results for Example 1
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Example 2
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196
t
p(t) [kN/m/m’]
1.0
0.02
- tunnel: E= 30 GPa, ν=0.33, ρ=2.0 t/m3
- building: E= 3 GPa, ν=0.30, ρ=2.0 t/m3
- soil: E=266 MPa, ν=0.33, ρ=2.0 t/m3
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Results Example 2
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Example 3
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Results of Example 3
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Influence of Soil Stiffness
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Comparison with a spring system
• Qualitatively similar
• Amplitudes higher, frequency lower
• Expected, as on the surface, not imbedded
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SOIL STRUCTURE INTERACTION WITH SIMPLE SPRINGS
Displacement u-X 101
Time
[sec]0.5 1.0 1.5 2.0 2.5
Displacement u-X [mm]
-20.000
-15.000
-10.000
-5.000
0.000
5.000
10.000
15.000
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SBFEM - Solution in the time domain
202WCCM 2010
( ) ( ) ( )0
t
b bt t t d = −r M u
( ) ( ) ( )
( ) ( ) ( )
( )
( ) ( )
ss sb s ss sb s ss sb s
bs bb b bs bb b bs bb b
s
b b
t t t
t t t
t
t t
+ +
= −
M M u C C u K K u
M M u C C u K K u
p 0
p r
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Convolution Integral
• For“ larger“ values of t, the unit impulse matrix grows unlimited
• Thus the noisy influence of early times becomes numerically
dominant
• Computers with limited precision can not handle that
203WCCM 2010
( ) ( ) ( )0
t
b bt t t d = −r M u
( )b tM
t
bC
bK
, ( )b f tM
C
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Discretized “Integration by parts”
• Based on the classical discretization scheme for a
constant value of M within one time step.
• We can drop the last term, and we can split the sum
numerically for a given limiting step number n
204WCCM 2010
( ) ( )1
1 1 1 1 0
1 2
i i
i i j j j i j i j i j i
j j
− − + − − + −
= =
= − = + − − r M u u u M u M M u M
( ) ( )1 1 1
1 1
2 2
i n i
j i j i j j i j i j n j
j j j n
− − − − + − − + −
= = =
− − + u M M u M M M u
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Integration by parts
• As we start with velocity zero the first part will vanish
• As the derivative of the unit impulse matrix M
converges to a constant value we may simplify the
last remaining integral term
205WCCM 2010
( ) ( )
( ) ( ) ( ) ( )( )
( )
0
0
0 0
t
b
tb
b b
t t d
d tt t t d
dt
− =
− − −
M u
MM u M u u
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Simplified Representation of the M-Matrix
• The Unit Impulse Matrix can be decomposed into three parts
constant, linear and a part which tends to zero for late times:
206WCCM 2010
( )b tM
tMt1Mt −
1mt −
mt1t0
M
M
1 m M
1M
−M
m
M
1m
−M
1
M
0
M
... ...
( ) ( ),( ) ( )b b b b ft H t tH t t = + +M C K M
( )b tM
t
bC
bK
, ( )b f tM
C
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Stabilisation of the Integration Scheme
• Classical integration with a constant value of M is only
unconditional stable. The time step has to be selected below a
certain stability criteria.
• There are well known techniques for time dependant problems
using a linear variation of the acceleration and stabilizing the
solution with an extrapolation parameter (0.5 < < 2.0).
• More formulas in the paper!
WCCM 2010 207
( ) 1 111m m m − −
−= − +m m m
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Stabilisation of the Integration Scheme
208WCCM 2010
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Stabilisation of the Integration Scheme
209WCCM 2010
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CPU Time
210WCCM 2010
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Example:
rigid embedded foundation
211WCCM 2010
0( ) /P t P
/stc b
0 1.5 3
1
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Required CPU Time
212WCCM 2010
t‘ = N·t
M = Number of
intervals of size t‘ for Unit
Impulse Matrix
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Vertical displacement
213WCCM 2010
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Non linear Analysis for a Frame
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Conclusion I
• Improved evaluation of the acceleration unit-impulse response
matrix by a new integration scheme based on the piece-wise
linear approximation within time step size and an extrapolation
parameter
• truncation time after which the acceleration unit-impulse
response matrix is linearized.
• Soil-structure interaction force vector represented by the
convolution integral is evaluated using a new and very efficient
scheme based on the integration by parts.
WCCM 2010 215
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Conclusion II
• The combination of these enhancements leads to a
very significant reduction of computational effort and
linear dependency with respect to the number of time
steps.
• No instabilities have been observed
• So we call it a high performance SBFEM method.
WCCM 2010 216