hollow section joints in trusses
DESCRIPTION
Hollow Section Joints in Trusses - Joints & BehaviourTRANSCRIPT
![Page 1: Hollow Section Joints in Trusses](https://reader031.vdocuments.us/reader031/viewer/2022013105/552e4f815503462c158b48ca/html5/thumbnails/1.jpg)
Wardenier RHS Joints - Oslo Course 2009
Hollow Section Joints in Trusses
Intro Joints & Behaviour
![Page 2: Hollow Section Joints in Trusses](https://reader031.vdocuments.us/reader031/viewer/2022013105/552e4f815503462c158b48ca/html5/thumbnails/2.jpg)
Wardenier RHS Joints - Oslo Course 2009
Trusses
![Page 3: Hollow Section Joints in Trusses](https://reader031.vdocuments.us/reader031/viewer/2022013105/552e4f815503462c158b48ca/html5/thumbnails/3.jpg)
Wardenier RHS Joints - Oslo Course 2009
Most common Combinations of sections
for trusses
Brace Chord Joint
CC
RR
CR
RI
CI
![Page 4: Hollow Section Joints in Trusses](https://reader031.vdocuments.us/reader031/viewer/2022013105/552e4f815503462c158b48ca/html5/thumbnails/4.jpg)
Wardenier RHS Joints - Oslo Course 2009
Hollow Section Trusses
a. Warren truss
b. Pratt truss
c. Vierendeel truss
d. truss with cross braces
Warren Type : K-joints
Pratt Type : N-joints
Vierendeel Type : T-joints
Cross brace Type : KT - joints
X - joints
![Page 5: Hollow Section Joints in Trusses](https://reader031.vdocuments.us/reader031/viewer/2022013105/552e4f815503462c158b48ca/html5/thumbnails/5.jpg)
Wardenier RHS Joints - Oslo Course 2009
Basic Types of Joints
![Page 6: Hollow Section Joints in Trusses](https://reader031.vdocuments.us/reader031/viewer/2022013105/552e4f815503462c158b48ca/html5/thumbnails/6.jpg)
Wardenier RHS Joints - Oslo Course 2009
Definition of eccentricity (joint design)
![Page 7: Hollow Section Joints in Trusses](https://reader031.vdocuments.us/reader031/viewer/2022013105/552e4f815503462c158b48ca/html5/thumbnails/7.jpg)
Wardenier RHS Joints - Oslo Course 2009
Definition of Gap and Overlap
![Page 8: Hollow Section Joints in Trusses](https://reader031.vdocuments.us/reader031/viewer/2022013105/552e4f815503462c158b48ca/html5/thumbnails/8.jpg)
Wardenier RHS Joints - Oslo Course 2009
Definition of Load capacity ultimate load)
Maximum
or load at a
3%d0 or 3%b0
deformation
![Page 9: Hollow Section Joints in Trusses](https://reader031.vdocuments.us/reader031/viewer/2022013105/552e4f815503462c158b48ca/html5/thumbnails/9.jpg)
Wardenier RHS Joints - Oslo Course 2009
Further: Service ability criteria
•• Deformation < 1% chord width or chord diameterDeformation < 1% chord width or chord diameter
•• crack initiationcrack initiation
![Page 10: Hollow Section Joints in Trusses](https://reader031.vdocuments.us/reader031/viewer/2022013105/552e4f815503462c158b48ca/html5/thumbnails/10.jpg)
Wardenier RHS Joints - Oslo Course 2009
A : chord face plastification
B : chord punching shear
C : brace effective width
D : chord shear failure
E : local buckling brace
F : local buckling chord
Failure Modes
e.g. for
RHS K gap joints
![Page 11: Hollow Section Joints in Trusses](https://reader031.vdocuments.us/reader031/viewer/2022013105/552e4f815503462c158b48ca/html5/thumbnails/11.jpg)
Wardenier RHS Joints - Oslo Course 2009
Symbols used (e.g. for K-Joints) d
b
h
t
e
g
0
1
2
β γ θ τ
b0
h0
t0 θ2
b2 d2
h2 h1
b1 d1
θ1
t2 t1
g
+e
N1 N2
N0
1 2
0
![Page 12: Hollow Section Joints in Trusses](https://reader031.vdocuments.us/reader031/viewer/2022013105/552e4f815503462c158b48ca/html5/thumbnails/12.jpg)
Wardenier RHS Joints - Oslo Course 2009
For Square Hollow Sections:
T and X-joints:
K gap joints:
KT joints:
For Rectangular Hollow Sections, include rectangularity,
e.g. for K gap joints:
0
1
b
b=β
0
21
2 b
bb +=β
0
321
3b
bbb ++=β
0
2211
4b
hbhb +++=β
Joint parameters
b0
h0
t0 θ2
b2 d2
h2 h1
b1 d1
θ1
t2 t1
g
+e
N1 N2
N0
1 2
0
![Page 13: Hollow Section Joints in Trusses](https://reader031.vdocuments.us/reader031/viewer/2022013105/552e4f815503462c158b48ca/html5/thumbnails/13.jpg)
Wardenier RHS Joints - Oslo Course 2009
0
0
0
0
t
bor
t
d2 =γ
0b
hi=η
00
0
yfA
Nn
⋅=
0t
ti=τ
Joint parameters
b0
h0
t0 θ2
b2 d2
h2 h1
b1 d1
θ1
t2 t1
g
+e
N1 N2
N0
1 2
0
![Page 14: Hollow Section Joints in Trusses](https://reader031.vdocuments.us/reader031/viewer/2022013105/552e4f815503462c158b48ca/html5/thumbnails/14.jpg)
Wardenier RHS Joints - Oslo Course 2009
Truss Behaviour
• Assume pin ended Joints but only if :
- the governing elements (joints or members) have
sufficient deformation/rotation capacity
If loads between the joints: assume continuous chords
![Page 15: Hollow Section Joints in Trusses](https://reader031.vdocuments.us/reader031/viewer/2022013105/552e4f815503462c158b48ca/html5/thumbnails/15.jpg)
Wardenier RHS Joints - Oslo Course 2009
Truss Behaviour
For Vierendeel trusses: use moment joints
(stiffness is important)
![Page 16: Hollow Section Joints in Trusses](https://reader031.vdocuments.us/reader031/viewer/2022013105/552e4f815503462c158b48ca/html5/thumbnails/16.jpg)
Wardenier RHS Joints - Oslo Course 2009
General Design Aspects for Trusses
• Depth h ≅ 1/10 to 1/16 L; generally 1/15 L
• pin jointed members if critical parts (members or joints)
have sufficient rotation capacity → secondary moments can
be neglected for static design
• if possible: center lines noding
• gap joints preferred above overlap joints (tolerances)
• optimize chords, however considering joint strength
• consider the joint strength always in the conceptual design
![Page 17: Hollow Section Joints in Trusses](https://reader031.vdocuments.us/reader031/viewer/2022013105/552e4f815503462c158b48ca/html5/thumbnails/17.jpg)
Wardenier RHS Joints - Oslo Course 2009
- end preparation
- fitting (tolerances)
- welding
Gap joints vs Overlap joints
ggapoverlap
![Page 18: Hollow Section Joints in Trusses](https://reader031.vdocuments.us/reader031/viewer/2022013105/552e4f815503462c158b48ca/html5/thumbnails/18.jpg)
Wardenier RHS Joints - Oslo Course 2009
Multiplanar trusses
![Page 19: Hollow Section Joints in Trusses](https://reader031.vdocuments.us/reader031/viewer/2022013105/552e4f815503462c158b48ca/html5/thumbnails/19.jpg)
Wardenier RHS Joints - Oslo Course 2009
Joint strength related to that for uniplanar jointsbut additional:
- Geometrical effect
- Loading effect
(see left)
Multiplanar Truss Behaviour
![Page 20: Hollow Section Joints in Trusses](https://reader031.vdocuments.us/reader031/viewer/2022013105/552e4f815503462c158b48ca/html5/thumbnails/20.jpg)
Wardenier RHS Joints - Oslo Course 2009
Hollow Section Joints in Frames
Types of Joints
![Page 21: Hollow Section Joints in Trusses](https://reader031.vdocuments.us/reader031/viewer/2022013105/552e4f815503462c158b48ca/html5/thumbnails/21.jpg)
Wardenier RHS Joints - Oslo Course 2009
Bolted joint to a fin plate
![Page 22: Hollow Section Joints in Trusses](https://reader031.vdocuments.us/reader031/viewer/2022013105/552e4f815503462c158b48ca/html5/thumbnails/22.jpg)
Wardenier RHS Joints - Oslo Course 2009
Bolted joint to a T stub
![Page 23: Hollow Section Joints in Trusses](https://reader031.vdocuments.us/reader031/viewer/2022013105/552e4f815503462c158b48ca/html5/thumbnails/23.jpg)
Wardenier RHS Joints - Oslo Course 2009
Bolted joint to a welded I section stub
![Page 24: Hollow Section Joints in Trusses](https://reader031.vdocuments.us/reader031/viewer/2022013105/552e4f815503462c158b48ca/html5/thumbnails/24.jpg)
Wardenier RHS Joints - Oslo Course 2009
Single sided bolted joint
![Page 25: Hollow Section Joints in Trusses](https://reader031.vdocuments.us/reader031/viewer/2022013105/552e4f815503462c158b48ca/html5/thumbnails/25.jpg)
Wardenier RHS Joints - Oslo Course 2009
Welded RHS beam to column joints
![Page 26: Hollow Section Joints in Trusses](https://reader031.vdocuments.us/reader031/viewer/2022013105/552e4f815503462c158b48ca/html5/thumbnails/26.jpg)
Wardenier RHS Joints - Oslo Course 2009
Stiffened beam to column joints
![Page 27: Hollow Section Joints in Trusses](https://reader031.vdocuments.us/reader031/viewer/2022013105/552e4f815503462c158b48ca/html5/thumbnails/27.jpg)
Wardenier RHS Joints - Oslo Course 2009
Basic behaviour of Hollow Section Joints
![Page 28: Hollow Section Joints in Trusses](https://reader031.vdocuments.us/reader031/viewer/2022013105/552e4f815503462c158b48ca/html5/thumbnails/28.jpg)
Wardenier RHS Joints - Oslo Course 2009
• follow the forces
• identify potential failure locations
• deform the structure under the acting loads
• consider the local stiffness and the material behaviour
• identify the possible failure modes
General approach
![Page 29: Hollow Section Joints in Trusses](https://reader031.vdocuments.us/reader031/viewer/2022013105/552e4f815503462c158b48ca/html5/thumbnails/29.jpg)
Wardenier RHS Joints - Oslo Course 2009
Example: Plate to RHS joint
![Page 30: Hollow Section Joints in Trusses](https://reader031.vdocuments.us/reader031/viewer/2022013105/552e4f815503462c158b48ca/html5/thumbnails/30.jpg)
Wardenier RHS Joints - Oslo Course 2009
Example
• plate
• weld
• chord (lamellar tearing)
• chord (face plastification)
• chord (punching shear)
• chord (side wall failure) (yielding, crippling)
Possible failure locations
![Page 31: Hollow Section Joints in Trusses](https://reader031.vdocuments.us/reader031/viewer/2022013105/552e4f815503462c158b48ca/html5/thumbnails/31.jpg)
Wardenier RHS Joints - Oslo Course 2009
Example
Plate to RHS chord joint - plate failure
![Page 32: Hollow Section Joints in Trusses](https://reader031.vdocuments.us/reader031/viewer/2022013105/552e4f815503462c158b48ca/html5/thumbnails/32.jpg)
Wardenier RHS Joints - Oslo Course 2009
Example
Plate to RHS chord joint - weld failure
Weld failure should be
avoided
(yielding only possible
over a small distance)
![Page 33: Hollow Section Joints in Trusses](https://reader031.vdocuments.us/reader031/viewer/2022013105/552e4f815503462c158b48ca/html5/thumbnails/33.jpg)
Wardenier RHS Joints - Oslo Course 2009
Example
Plate to RHS chord joint - chord lamellar tearing
No photo for this failure mode
![Page 34: Hollow Section Joints in Trusses](https://reader031.vdocuments.us/reader031/viewer/2022013105/552e4f815503462c158b48ca/html5/thumbnails/34.jpg)
Wardenier RHS Joints - Oslo Course 2009
Example
Plate to RHS chord joint - other chord failure modes
chord
punching shear
side wall yielding
chord face plastification
![Page 35: Hollow Section Joints in Trusses](https://reader031.vdocuments.us/reader031/viewer/2022013105/552e4f815503462c158b48ca/html5/thumbnails/35.jpg)
Wardenier RHS Joints - Oslo Course 2009
Plate to RHS joint (plate failure)
Different stiffness for q1 and q2
![Page 36: Hollow Section Joints in Trusses](https://reader031.vdocuments.us/reader031/viewer/2022013105/552e4f815503462c158b48ca/html5/thumbnails/36.jpg)
Wardenier RHS Joints - Oslo Course 2009
Plate to RHS joint(plate failure)
Stress and resulting deformation
1. Method:
Consider the
deformations under a
uniform stress
![Page 37: Hollow Section Joints in Trusses](https://reader031.vdocuments.us/reader031/viewer/2022013105/552e4f815503462c158b48ca/html5/thumbnails/37.jpg)
Wardenier RHS Joints - Oslo Course 2009
Plate to RHS joint (plate failure)
Compatibility
Resulting stress
pattern in plate
![Page 38: Hollow Section Joints in Trusses](https://reader031.vdocuments.us/reader031/viewer/2022013105/552e4f815503462c158b48ca/html5/thumbnails/38.jpg)
Wardenier RHS Joints - Oslo Course 2009
Stress and resulting deformation for a rigid plate
2. Method:
Plate stiffness >>
stiffness RHS face
Plate to RHS joint (plate failure)
![Page 39: Hollow Section Joints in Trusses](https://reader031.vdocuments.us/reader031/viewer/2022013105/552e4f815503462c158b48ca/html5/thumbnails/39.jpg)
Wardenier RHS Joints - Oslo Course 2009
a: ductile →redistribution of stresses
b: brittle →failure at reaching in one
point the ultimate stress
Effect of material
![Page 40: Hollow Section Joints in Trusses](https://reader031.vdocuments.us/reader031/viewer/2022013105/552e4f815503462c158b48ca/html5/thumbnails/40.jpg)
Wardenier RHS Joints - Oslo Course 2009
Stress pattern at failure (material a)
![Page 41: Hollow Section Joints in Trusses](https://reader031.vdocuments.us/reader031/viewer/2022013105/552e4f815503462c158b48ca/html5/thumbnails/41.jpg)
Wardenier RHS Joints - Oslo Course 2009
Chord side
wall failure
Other failure modes e.g. side wall failure
![Page 42: Hollow Section Joints in Trusses](https://reader031.vdocuments.us/reader031/viewer/2022013105/552e4f815503462c158b48ca/html5/thumbnails/42.jpg)
Wardenier RHS Joints - Oslo Course 2009
The end of the
lectures on:
introduction into
the joint behaviour
![Page 43: Hollow Section Joints in Trusses](https://reader031.vdocuments.us/reader031/viewer/2022013105/552e4f815503462c158b48ca/html5/thumbnails/43.jpg)
Wardenier RHS Joints - Oslo Course 2009
IIW (2008) Relation to the Basic Types of Joints
0.5N sinθ
0.5N sinθ
θ
N
N cosθ
=
0.5N sinθ
θ
0.5N
0.5N cosθ
0.5N sinθ
θ
+
0.5N
0.5N cosθ
Example: Checking of a K joint with imbalanced brace loads