Design of Machine Elements – I 10ME52Department of Mechanical Engineering, SJBIT, Bengaluru. Page 1 ASSIGNMENT QUESTIONS UNIT 1 INTRODUCTION 1. What are the factors to be considered for selection of material for a machine component? 2. What are the basic requirements of machine elements? Explain briefly. 3. Draw stress - strain diagram for mild steel subjected to tension. Explain the significance of salient points. 4. Identify the following engineering materials giving specifications: i) FG350. ii) FeE300. iii) C35Mn75. iv) X20Cr18Ni2. 5. An unknown weight falls through 10 mm on a collar rigidly attached to the lower end of a vertical bar 3000 mm long and 600 mm2in section. If the maximum instantaneous extension of bar is 2mm, what is the corresponding stress and the value of unknown weight? Take E = 200 kN/mm2. 6. A point in a structural member subjected to plane stress is shown in Fig.Q.l(b). Determine the following: i) Normal and tangential stress intensities on plane MN inclined at 45°. ii) Principal stresses and their direction iii) Maximum shear stress and the direction of the planes on which it occurs.
Design of Machine Elements – I 10ME52Department of Mechanical Engineering, SJBIT, Bengaluru. Page 2 7. Define Machine Design? Explain the importance of material selection in design? 8. What are the advantages of malleable cast iron over white or grey castiron? 9. A standard alloy steel used for making engineering components is 20Cr18 Ni2. State the composition of the steel. 10. List at least five important non-metals commonly used in machine design. 11. State at least 5 important mechanical properties of materials to be considered in machine design. 12. Define resilience and discuss its implication in the choice of materials in machine design. 13. Discuss ‘factor of safety’ in view of the reliability in machine design. 14. Suggest briefly the steps to be followed by a designer. 15. Define standards and codes. 16. Briefly explain the important mechanical properties of metals. 17. Draw stress-strain diagram for a ductile material and a brittle material and show the salient points on them. 18. What is an adaptive design? 19. How are plain carbon steel designated? 20. Sketch and explain biaxial, triaxial and principal stresses.