engineering mechanics statics - meriam and kraige (5th ed)engineering mechanics statics - meriam and...
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Engineering Mechanics StaticsTRANSCRIPT
ADDIS ABABA UNIVERSITYFaculty of Technology
Department ofCivil EngineeringStrength of Materials
Strength of Materials(ceng 1002) Semester II 2008
Introduction
specimen in tensile test (ultimate strength), imwf Stuttgart
ADDIS ABABA UNIVERSITYFaculty of Technology
Department ofCivil EngineeringStrength of Materials
Strength of MaterialsMechanics of MaterialsMechanics of Solids
from rigid to deformable bodies �
ADDIS ABABA UNIVERSITYFaculty of Technology
Department ofCivil EngineeringStrength of Materials
stress
Cutting plane � inner actionequilibrium at particle
stress
ADDIS ABABA UNIVERSITYFaculty of Technology
Department ofCivil EngineeringStrength of Materials
Stress
F F
F F
F
stress σ = F / A [kN/cm²]
example: suspended rod
- cross section area A [cm²]
- Force F [kN]
cutting planeinner actionequilibrium at particle
σ
F
A
ADDIS ABABA UNIVERSITYFaculty of Technology
Department ofCivil EngineeringStrength of Materials
Strain
F
2F
2F
example: suspended rod
-Length L-Elongation ∆L
L L
∆L2=2∆L1
strain ε = ∆L / L
F
F
L
∆L1
strain εproportional to stress σ
ADDIS ABABA UNIVERSITYFaculty of Technology
Department ofCivil EngineeringStrength of Materials
Hooke’s Law
linear equation : σ = Eε
E = Young�s Modulus
strain ε
stress σ[kN/m²]
gradient E [kN/m²]
ADDIS ABABA UNIVERSITYFaculty of Technology
Department ofCivil EngineeringStrength of Materials
Hooke’s Law
Example: Bungee Cable
- Stress Analysis
- Serviceability
ADDIS ABABA UNIVERSITYFaculty of Technology
Department ofCivil EngineeringStrength of Materials
Material Properties
stress-strain diagram of mild steelaxial loadingtensile test
determination oftensile strengthand Young�s Modulus
area of plasticity
ADDIS ABABA UNIVERSITYFaculty of Technology
Department ofCivil EngineeringStrength of Materials
Material Properties
ε
σductile material brittle material
ε
σ
tensile test
image of failure, compression test
ADDIS ABABA UNIVERSITYFaculty of Technology
Department ofCivil EngineeringStrength of Materials
deflection due to loading
strain
stre
ss
specimen in tensile test (ultimate strength), imwf Stuttgart
Material Properties
ADDIS ABABA UNIVERSITYFaculty of Technology
Department ofCivil EngineeringStrength of Materials
Material Properties
Concrete specimen in compression test
free blocked
ADDIS ABABA UNIVERSITYFaculty of Technology
Department ofCivil EngineeringStrength of Materials
Deflection due to condition of loading
tension compression bending torque shear
ADDIS ABABA UNIVERSITYFaculty of Technology
Department ofCivil EngineeringStrength of Materials
Material Properties
Timber
perpendiculartensile stress due to shrinkage
ADDIS ABABA UNIVERSITYFaculty of Technology
Department ofCivil EngineeringStrength of Materials
Material Properties
Timber
orthotropic material behaviour
ADDIS ABABA UNIVERSITYFaculty of Technology
Department ofCivil EngineeringStrength of Materials
Material Properties
cycling curves for material creepe.g. synthetics, textiles Danzer, S.18
time
time
time
time
ADDIS ABABA UNIVERSITYFaculty of Technology
Department ofCivil EngineeringStrength of Materials
Material Properties
Steeltime
time
time
time
deflection due to temperature (fire exposure) Brandschutzatlas
ADDIS ABABA UNIVERSITYFaculty of Technology
Department ofCivil EngineeringStrength of Materials
Material Properties
Steel deflection due to temperature (fire exposure) Brandschutzatlas
ADDIS ABABA UNIVERSITYFaculty of Technology
Department ofCivil EngineeringStrength of Materials
Stability
Buckling of columnsEuler Formula
ADDIS ABABA UNIVERSITYFaculty of Technology
Department ofCivil EngineeringStrength of Materials
Stability
Buckling of columns
ADDIS ABABA UNIVERSITYFaculty of Technology
Department ofCivil EngineeringStrength of Materials
Stability
Buckling of columns
ADDIS ABABA UNIVERSITYFaculty of Technology
Department ofCivil EngineeringStrength of Materials
Concept of Design
load assumption : safety factor
material strength : reduction factor
stress analysis : design stress < allowable stress (stability)
serviceability : design deflection < limit deflection
ADDIS ABABA UNIVERSITYFaculty of Technology
Department ofCivil EngineeringStrength of Materials
Unexpected loads
ADDIS ABABA UNIVERSITYFaculty of Technology
Department ofCivil EngineeringStrength of Materials
Design Project “Bottle Bubble” Example: from an unknown material to construction
University of Karlsruhe, 2005
ADDIS ABABA UNIVERSITYFaculty of Technology
Department ofCivil EngineeringStrength of Materials
Material Behaviour - determining the Elastic Modulus
ADDIS ABABA UNIVERSITYFaculty of Technology
Department ofCivil EngineeringStrength of Materials
ADDIS ABABA UNIVERSITYFaculty of Technology
Department ofCivil EngineeringStrength of Materials
Calculation
ADDIS ABABA UNIVERSITYFaculty of Technology
Department ofCivil EngineeringStrength of Materials
ADDIS ABABA UNIVERSITYFaculty of Technology
Department ofCivil EngineeringStrength of Materials
Lectures: Monday 8:15 � 10:00 a.m. Room No4
Karsten Schlesier
Tutorials: Friday 8:15 � 11:40 a.m. Room No4
Mesgana Seyoum
Consultation: Thursday 4:00 � 6:00 p.m. Room 211
Karsten Schlesier
ADDIS ABABA UNIVERSITYFaculty of Technology
Department ofCivil EngineeringStrength of Materials
Final Exam14.07.2008mo16
07.07.2008mo15
Workshop30.06.2008mo14
Lab Session 223.06.2008mo13
Buckling Analysis616.06.2008mo12
Stability of Compression Members609.06.2008mo11
Compound Stresses 502.06.2008mo10
Torsion426.05.2008mo9
Mid-Semester Exam19.05.2008mo8
Lab Session 112.05.2008mo7
Deflection of Beams305.05.2008mo6
Bending of Beams328.04.2008mo5
Strain - Axial Load221.04.2008mo4
Stress - Axial Load114.04.2008mo3
Introduction to SOM07.04.2008mo2
Course Information04.04.2008fr1
ContentChapterDatedayweek
Calender Semester II 2008
ADDIS ABABA UNIVERSITYFaculty of Technology
Department ofCivil EngineeringStrength of Materials
Course Outline
1 Stress – Axial LoadsNormal Stress, Shearing Stress, Transformation of Stress, Concept of Design
2 Strain – Axial LoadsStrain, Stress-Strain Diagram, Hooke�s Law, Deflection under Axial Load, Material Properties
3 Bending of BeamsStress due to pure Bending, Shearing Stress in Beams, Moment of Inertia, Stress Distribution, Deflection of Beams, Design of Beams
4 TorsionMoment of Torsion, Shearing Stresses and Deformations of Circular Shafts
5 Analysis of plane StressCompound Stresses, Combined Stresses, Transformation of Stress, Mohr�s Circle
6 Stability of Compression MembersEuler Formula, Buckling Load, Buckling Analysis
ADDIS ABABA UNIVERSITYFaculty of Technology
Department ofCivil EngineeringStrength of Materials
Assessment / Requirements
Minimum of 75% attendance during lecture hours and tutorials, 100% attendance during practical work sessions (except for unpredicted mishaps) � watch notice for further details.
Quota of Total Course Credit: 40% mid-semester examination40% final-semester examination20% assignments, practical workshop
Literature
Popov, E.P., Mechanics of Materials Beer and Johnson, Mechanics of Materials, 2001Gere and Timoshenko, Mechanics of Materials, 1990
E-learning Platform
www.elboon.net (elearning board online) � under construction!www.ocw.mit.edu MIT open courseware � Solid Mechanics
ADDIS ABABA UNIVERSITYFaculty of Technology
Department ofCivil EngineeringStrength of Materials
ADDIS ABABA UNIVERSITYFaculty of Technology
Department ofCivil Engineering
G. Galileo