Mechanical Metallurgy Practice Test 1

1. The part of strain tensor which involves in the shape change rather than the volume change is called strain deviator ε’ij.

2. If the specimen is deformed plastically beyond the yield stress in one direction, e.g., tension and then after unloading it is loaded in the opposite direction, e.g., compression, it is found that the yield stress is less than the original yield stress. This dependence of yield stress on direction loading is called ____________

3. A strain gauge measurement made on the free aluminum surface indicates the principle strains 0.003 and 0.002. What are the principal stresses? (Given that poison's ratio for aluminum=0.33, young modulus = 70 GPa)

4. Which of the following factors change the value of the elastic constant of any material?

5. The following flow curve shows the deformation behavior of the material in the plastic region. The material is deformed till ε1 and released; the material immediately reached to strain ε2. And the time strain reached to ε3. So, there is a delayed recovery of strain. This is behavior of material is called _________

6. A wedge shape body is under stress with principal stresses being σx=25MPa and σy=20MPa. At a certain angle β, the components of stresses are resolved into σ1 & σ2, where both σ1 & σ2 are normal to each other. If the value of σ1=18MPa, find the value of σ2?

7. A cubic shape body is subjected to stresses as shown in the figure below. If both are stresses are equal in magnitude, calculate the shear stresses on black and green planes.

8. Which of the following relation is not correct?

9. In the case of pure shear forces, normal stresses develop in all the planes except the planes where shear stresses are maximum.

10. Matrix (2-dimensional arrays) is a second rank tensor.