A G192018 Pages:3
Reg No.: Name:
APJ ABDUL KALAM TECHNOLOGICAL UNIVERSITY
SEVENTH SEMESTER B.TECH DEGREE EXAMINATION(R&S), DECEMBER 2019
Course Code: ME401
Course Name: DESIGN OF MACHINE ELEMENTS - I
Max. Marks: 100 Duration: 3 Hours
(i) Use of approved design data book is permitted
(11) Missing data if any may be suitable assumed
PART A
Answer any two full questions, each carries 15 marks. Marks
1 9) What do you mean by preferred numbers? Explain with the help of an example. (5)
b) Define the term notch sensitivity. Establish the relationship between notch (5)
sensitivity and fatigue stress concentration factor.
c) Distinguish between ductile and brittle materials with the help of a stress- strain (5)
diagram?

2 a) Acantilever beam of square section supports an electric motor weighing 100011 (5)
at a distance of 400 mm from the fixed end. If the allowable stress of beam
material is 100 N/mm’, Determine section of beam.

b) A mild steel shaft is subjected to a 3500 N-m of bending moment at its critical (10)
point and transmits a torque of 2500 N-m. The shaft is made of steel having a
yield stress of 230 MPa. Estimate the size of the shaft (FOS =2) based on
following theories of failure
1. Maximum normal stress theory
2. Maximum shear stress theory
3. Distortion energy theory
3 9) Whatare the factors affecting the endurance strength? (3)
b) Explain the procedure for the design of a component for finite life under varying (4)
amplitude loading?
c) A steel shaft is subjected to a torque that varies over a range of +/- 40%. (8)

Determine the diameter of the shaft if it transmits 14 kW at 225 rpm. The
material has a ultimate tensile strength of 600 MPa and yield strength of 400
MPa. FOS =3.

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