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Comprehensive
Examination
ประธานกรรมการ
ผศ.ดร. ธรพงศ จนทรเพง
กรรมการรวม
อ.ดร. รงสรรค วงศจรภทร
ผแทนบณฑตวยาลย
อ.ดร. ปารเมศ กาแหงฤทธรงค
Coursework Outline
Advanced Solid Mechanics
Mathematics Methods in Structural
Engineering
Advanced Reinforced Concrete
Matrix Methods in Structural Analysis
Bridge Design
Advanced Steel Structures
Advanced Concrete Technology
วชาเอกบงคบ
วชาเอกเลอก
Advanced
Solid Mechanics
Basic of Analysis
Equilibriam
Constitutive Law
Kinematics
Basic of Analysis
Displacement
External Forces
and Moments Strains
Internal Forces
And Moment Stress
Static Equivalency
ε =∆LL
σ = Eε
σ =Mc
I
Stress-strain relationship
Stress Tensor
𝑇 =𝜎𝑥𝑥 𝜎𝑥𝑥 𝜎𝑥𝑥𝜎𝑥𝑥 𝜎𝑥𝑥 𝜎𝑥𝑥𝜎𝑥𝑥 𝜎𝑥𝑥 𝜎𝑥𝑥
Shear stress
Normal stress
𝜎𝑥𝑥
Plane-x Direction-y
Strain Tensor
𝑇 =𝜀𝑥𝑥 𝜀𝑥𝑥 𝜀𝑥𝑥𝜀𝑥𝑥 𝜀𝑥𝑥 𝜀𝑥𝑥𝜀𝑥𝑥 𝜀𝑥𝑥 𝜀𝑥𝑥
Failure Criteria
Mode of failure
1. By excessive deflection
2. By general yielding
3. By fracture
4. By instability (Bucking)
- Yielding of Brittle Metals
- Yielding of Ductile Metals
- Alternative Yield Criteria
1. Maximum Principal Stress Theory 𝜎𝑒 = max 𝜎1 , 𝜎2 , 𝜎3
𝑓 = 𝜎𝑒 − 𝑌
Yielding
of Brittle
Metals
3. Strain Energy Density Criterion
𝜎𝑒 = 𝜎12 + 𝜎22 + 𝜎23 − 2𝜈(𝜎1𝜎2 + 𝜎2𝜎3 + 𝜎1𝜎3)
𝑓 = 𝜎𝑒2 − 𝑌2
2. Maximum Principal Stain Theory 𝜎𝑒 = max
𝑖>𝑗>𝑘𝜎𝑖 − 𝜈𝜎𝑗 − 𝜈𝜎𝑘
𝑓 = 𝜎𝑒 − 𝑌
Yielding
of Ductile
Metals
1. Maximum Shear-Stress Theory
𝜎𝑒 = max (𝜏1, 𝜏2, 𝜏3) ,𝑓 = 𝜎𝑒2 − 𝑌2
2. Distortional Energy Density Criterion (Von mises)
𝜎𝑒 = 12
[ 𝜎1 − 𝜎2 2 + 𝜎2 − 𝜎3 2 + 𝜎3 − 𝜎1 2] ,
𝑓 = 𝜎𝑒2 − 𝑌2
1. Mohr-Coulomb Yield Criterion 𝑓 = 𝜎1 − 𝜎3 + 𝜎1 + 𝜎3 sin𝜙 − 2𝑐 cos𝜙
2. Drucker-Prager Yield Criterion
𝑓 = 𝛼𝐼1 + 𝐽2 − 𝐾 𝛼 = 2 sin 𝜙3(3−sin 𝜙)
𝐾 = 6𝑐 cos 𝜙3(3−sin 𝜙)
Alternative
Yield
Criteria
Shear center
𝐹𝑙 = � 𝑞 𝑑𝑙𝑏
0 𝑞 =
𝑉𝑥𝑄𝐼𝑥
𝑒 =𝐹𝑙ℎ𝑉′
Linear Elastic
1. Symmetrical Bending : 𝜎𝑥𝑥 = 𝑀𝑥𝑌𝐼𝑥
, 𝜎𝑥𝑥 = 𝑀𝑦𝑋𝐼𝑦
2. Unsymmetrical Bending
– Load : 𝜎𝑥𝑥 = 𝑀𝑥𝑌𝐼𝑥
− 𝑀𝑦𝑋𝐼𝑦
– Geometry : 𝜎𝑥𝑥 = 𝑀𝑥(𝑥−𝑥 tan 𝛼)𝐼𝑥−𝐼𝑥𝑦 tan 𝛼
, tan𝛼 = 𝐼𝑥𝑦−𝐼𝑥 cot 𝜃𝐼𝑦−𝐼𝑥𝑦 cot 𝜃
Fully Plastic
𝑀𝑝 =𝑌𝑏ℎ2
4
Bending
Torsion
Linear Elastic
•Circular Cross Section
•Noncircular cross section
Inelastic
• Elastic-Plastic
• Fully Plastic
Matrix Methods in Structural
Analysis
Stiffness Method
Flexibility Method
1. Equilibrium of force
2. Compatibility of deformations
3. Hooke’s low
1. Equilibrium of force
2. Displacement continuity
3. Linear force-displacement
relationship
Stiffness Method
𝛿 = 𝐾 −1 𝐹
𝐹� = 𝐾� 𝛿
𝐹 = 𝐾 𝛿
𝑆 = 𝜎 𝛿
หา 𝐾� ใน Local coordinate System
Transform 𝐾� เปน global coordinate
System รวมเปน 𝐾
หา Nodal Displacement
หา Internal force จาก Stress matrix
Flexibility Method
𝑆 = 𝐵0 𝐹 + 𝐵1 𝑋
𝑆 = 𝑍 𝐹
𝑍 = 𝐵0 − 𝐵1(𝐵1𝑇𝐴𝐵1)−1𝐵1𝑇𝐴𝐵0
𝛿 = 𝑍 𝑇 𝐴 𝑆 = 𝐵0 𝑇 𝐴 𝑆
หา 𝐵0 และ 𝐵1จากการตดโครงสรางใหเปน
Primary structure ทมเสถยรภาพ
หา Internal force
หา Nodal Displacement
Mathematics
Methods in Structural
Engineering
Differential Equation
Ordinary differential equations (ODE)
Partial differential equations (PDE)
Algebraic equations Differential equations
𝑎𝑥2 + 𝑏𝑥 + 𝑐 = 0 𝑚𝑑2𝑦(𝑥)𝑑𝑥2 + 𝑐
𝑑𝑦(𝑥)𝑑𝑥 + y x
= sin(x)
Find the numerical values Find the functions
Ordinary differentiale
quations
(ODE)
Homogeneous Nonhomogeneous
0 = f(x) =
𝑦 = 𝑦ℎ 𝑦 = 𝑦ℎ + 𝑦𝑝
General solution General solution
+
Particular solution
Partial differential
equations
(PDE)
Fourier Series
𝑎0 = 1𝑇 ∫ 𝑓 𝑡 𝑑𝑡𝑇
0
𝑎𝑛 = 2𝑇 ∫ 𝑓 𝑡 cos 𝑛𝜔�𝑡 𝑑𝑡𝑇
0
𝑏𝑛 = 2𝑇 ∫ 𝑓 𝑡 sin 𝑛𝜔�𝑡 𝑑𝑡𝑇
0
𝑓 𝑡 = 𝑎0 + �𝑎𝑛 cos 𝑛𝜔�𝑡∞
𝑛=1
+ �𝑏𝑛 sin 𝑛𝜔�𝑡∞
𝑛=1
Matrix Algebra
Vector – Row vector : ∎ ∎ ∎ 1×𝑛
– Column vector : ∎∎∎ 𝑛×1
Matrix – Square Matrix : ∎ ∎∎ ∎ 𝑛×𝑛
– Rectangular Matrix : ∎ ∎ ∎∎ ∎ ∎ 𝑚×𝑛
System of linear equations
A x b
Uniqueness of solution
0
6
0 10
x1
x2 0
6
0 10
x1
x2 0
6
0 10
x1
x2
No Solution A = 0
Infinite Solution A = 0
Ill-condition A → 0
Eigenvalue Problems
Ax = λ x
Eigenvalues Eigenvectors A − λI x = 0
Trivial Solution x = 0
Nontrivial Solutions
from det(A − λ𝐼) = 0 Standard Form
Ax1 = λ1x1
Ax2 = λ2x2
Ax3 = λ3x3
⋮
Axn = λnxn
Roots of Equations
Bracketing methods
Bisection :
𝑥𝑟 = 𝑥𝑙+𝑥𝑢2
False-position :
𝑥𝑟 = 𝑥𝑢 −𝑓(𝑥𝑢)(𝑥𝑙−𝑥𝑢)𝑓 𝑥𝑙 −𝑓(𝑥𝑢)
Open methods
Newton-Raphson Method
𝑥𝑖+1 = 𝑥𝑖 −𝑓(𝑥𝑖)𝑓′(𝑥𝑖)
Interpolation
Assumption:
Data are accurate and distinct.
To do:
Find a smooth curve through the data points.
Curve fitting & Interpolation
Curve fitting
Assumption:
Data contain scatter(noise), usually due to
measurement errors.
To do:
Find a smooth curve that approximates
the data.
Numerical Differential & Integration
Differentiation
1. Finite difference approximations
2. Derivative by interpolation
Integration
1. Newton-Cote formulas
2. Gaussian integration
Advanced
Reinforced Concrete
พฤตกรรมการรบแรงดด
1. ชวงกอนการแตกราว
2. ชวงคอนกรตใตแกนสะเทนราวบางสวน
3. จดท เหลกเสรมถงจดคราก
4. ชวงหลกการเรมตนการครากของเหลก
ความสมพนธ M−𝛟 แบบประมาณ
ทจดเรมตนการคราก
ทกาลงประลย
ความสมพนธ M−𝛟 แบบประมาณ
𝑀𝑥 = 𝐴𝑠𝑓𝑥(𝑑 −𝑘𝑑3 ) ≤ 𝑀𝑢
𝜙𝑥 =𝜀𝑥
𝑑 − 𝑘𝑑
𝑀𝑢 = 𝐴𝑠𝑓𝑥𝑑(1 − 0.59𝜌𝑓𝑥𝑓′𝑐
)
𝜙𝑢 =0.003𝑘𝑢𝑑
ทจดเรมตนการคราก ทกาลงประลย
พฤตกรรมการรบแรงอด
เสาเหลกปลอกเกลยว เสาเหลกปลอกเดยว
พฤตกรรมการรบแรงอดรวมกนแรงดด
พฤตกรรมการรบแรงของเสาชะลด
1. คานชวงการเฉอนยาวมาก : a d⁄ = 6
2. คานชวงการเฉอนยาว : a d⁄ = 3 หรอ 4
3. คานชวงการเฉอนสน : 2.5 > a d > 1⁄
4. คานลก : a d ≤ 1⁄
พฤตกรรมการรบแรงเฉอน
พฤตกรรมการรบแรงบด
Advanced
Steel Structures
Beam Behavior– Flexure
Method of Plastic Analysis
1. Must have enough hinges to form mechanism
2. Moment diagram must be in equilibrium with applied load
3. lMl ≤ l𝑀𝑃 l everywhere
Stiffeners
Torsion of I-Shape member
𝑇 = 𝑇𝑠𝑠 + 𝑇𝑤
𝑇𝑠𝑠 = The portion of T resisted by torsional shear stresses
𝑇𝑤 = The portion of T resisted as a result warping restraint
Bridge Design
Bridge Design
1. Aesthetics
2. Bridge types
- Concrete bridge
- Steel bridge
- Wood bridge
- Composite bridge
3. General design considerations
4. Loads
5. Bridge/system analysis
Advanced Concrete Technology
Cement hydration
Cement microstructure
Admixture in Concrete
Mineral Admixture
inexpensive and eco-friendly.
Chemical
control setting or water requirement
Mineral improve some properties
Carbonation
Attack
Chloride
Attack
Sulfate
Attack
Alkali
Aggregate
Reactions