ME 53 – DESIGN OF MACHINE ELEMENTS

B.E./B.TECH.DEGREE THIRD UNIT EXAMINATIONS, AUG – 2012

REGULATIONS 2008

FIFTH SEMESTER

ME 53 – DESIGN OF MACHINE ELEMENTS

MECHANICAL ENGINEERING

Time: 1 1/2 Hours                                 Date: 08.08.2012                               Maximum: 50 marks

ANSWER ALL QUESTIONS

PART – A (9 x 2 = 18 marks)

1. Define welding.

2. Why are welded joints preferred over riveted joint?

3. How is welding classified?

4. State the limitation of welding.

5. Write down the formula for strength of fillet and double fillet.

6. What are the advantages of welding?

      7. State the two types of eccentric welded connections.

      8. Differentiate with a neat sketch the fillet welds subjected to parallel loading and transverse loading.

      9. What are the main indications of complete weld symbol?  

PART – B (ANSWER ANY TWO)

 (2 x 16 = 32 marks)

10. A shaft of rectangular cross section is weld section is to a support plate by means of fillet weld on its one end as shown in fig. The other end is loaded by 25KN. If the size of weld is 6mm, find the maximum normal and shear stress in the weld.  

           

11. Determine the required standard diameter of a uniform circular shaft carrying 2 pulleys of weight 2KN each. The shaft 750mm long is supported at the end and carries 2 pulleys at 250mm and 500mm from the left end. Pull on the right pulley is 10KN vertically downwards. The shaft transmits a torque of 3KN-m between the pulleys. Assume Kb=Kt=1.5 and allowable shear stress of 70N/mm².

12. The bracket arrangement as shown in fig. The protruding portion of this bracket consist of an ‘I’ cross section with a dimensions indicated and is welded to a support plate. The load to be supported is 30 kN and the arrangement should provide for the factor of safety is 1.6. Find the necessary weld size for the connection between the protruding portion and the support plate. The maximum shear stress in the weld should not exceed 125 N/ mm².