Question 1
Two samples of different materials have been tested under tensile loading conditions. The load-deformation diagram of the two materials is plotted in the below graph. The specimens have an initial diameter of 15 mm and an initial gauge length of 50 mm.
i. Determine
1. Proof strength for material M1
2. The tensile strength for the two materials
3. The modulus of elasticity of the two materials
4. The ductility of the two materials
ii. Explain the difference behaviour of those materials and discuss the limitations of
possible applications
Question 2
Below figure shows the dependence of impact energy on temperature of a material (notched bar impact test data). Explain the dependence of failure modes on temperature, and discuss the suitable environmental temperature region for the material.
Question 3
Creep occurs when a metal is subjected to a constant load at an elevated
temperature. Describe the creep behavior of metals, and discuss the impact of temperature and applied stress on creep rate.
Question 4
Dynamic loading has a significant effect on the lifetime (number of cycles to
failure) of materials. Plot the effect of stress magnitude (reversal) on a lifetime of mild steel, and discuss the advantages and disadvantages of this material for use in dynamic loading conditions