ME6503 DME Important Questions, DESIGN OF MACHINE ELEMENTS Answer Key – MECH 5th SEM Anna University

Unit -1 STEADY STRESSES AND VARIABLE STRESSES IN MACHINE MEMBERS

Part-A

1. What are the steps in machine design process?
2. How will you classify machined design and explain it?
3. Enumerate the most commonly used engineering materials and state at least oneimportant property and one application of each
4. Why are metals in their pure form unsuitable for industrial use?
5. Define ‘mechanical property’ of an engineering material. State any six mechanicalproperties give their definitions and one example of the material possessing the properties.

6. What are fits and tolerances? How are they designated
7. What do you understand by the nominal size and basic size?
8. Write short notes on the following:

1. Interchangeability
2. Tolerance
3. Allowance and
4. Fits

     9. What interference fits? is the difference in the type of assembly generally used in running fits and

10. Define unilateral and bilateral tolerance.
11. What is meant by ‘hole basis system’ and ‘shaft basic system’? Which one ispreferred and why?
12. Discuss the Indian standard system of limits and fits.
13. What are the commonly used fits according to Indian standards?
14. What do you understand by preferred numbers?

15. Write soderberg equation for a machine component subjected to

1. Combination of mean and variable torques
2. Combination of mean and variable bending moments.

16. How is the working stress calculated from the yield stress of a material?
17. What is meant by stress concentration? How do you take it into consideration in caseof a component subjected to dynamic loading?
18. For Ductile material, which of the strength is considered for designing a
    1. Component subjected to static loading
    2. Component subjected to fatigue loading
19. What is Gerber Theory?
20. What is the force required to punch a hole of diameter ‘d’ in a metal of thickness ‘t’ having ultimate shear strength as ‘Ʈu’?