Structural Analysis and Materials Science Flashcards
6 cards from real ME or MEng Master of Engineering practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Structural Analysis and Materials Science flashcards as text
The method of sections in truss analysis involves:
Answer: Cutting the truss and applying equilibrium to one portion
The method of sections cuts through the truss and applies three equilibrium equations to the free body of one portion, directly finding up to three unknown member forces.
Creep in materials refers to:
Answer: Slow, time-dependent plastic deformation under sustained load
Creep is the slow, progressive plastic deformation of a material under constant stress, typically significant at temperatures above 0.4 T_m (melting point).
In composite materials, the rule of mixtures gives the longitudinal (fiber-direction) Young's modulus as:
Answer: E_c = E_f·V_f + E_m·V_m
The rule of mixtures E_c = E_f·V_f + E_m·V_m applies for loading parallel to fibers, assuming equal strain in fiber and matrix (isostrain condition).
Castigliano's second theorem states that the deflection at a point in a structure equals:
Answer: The partial derivative of total strain energy with respect to the applied load at that point
Castigliano's theorem: δ_i = ∂U/∂P_i, where U is the total strain energy, allows deflection calculations in statically indeterminate and complex structures.
Which type of stress causes shear failure along a 45° plane in a uniaxially loaded ductile member?
Answer: Maximum shear stress
Maximum shear stress on planes at 45° to the principal stress axes causes slip and shear failure in ductile materials under uniaxial loading.
Transformation temperature A3 in the iron-carbon phase diagram represents:
Answer: The upper boundary of the two-phase (austenite + ferrite) region for hypoeutectoid steels
The A3 line is the upper critical temperature above which hypoeutectoid steels are fully austenitic; it decreases from 912°C (pure iron) to 723°C at 0.77% C.