Machine Component and Design (ME-602) - Important Questions

Discuss design considerations for fatigue loading in machine elements.

Explain fluctuating stresses and Goodman and Modified Goodman diagrams with neat sketches.

Explain Soderberg equation for fatigue failure design with neat diagram and state its application for ductile materials under fluctuating stresses.

A machine component is subjected to a flexural stress which fluctuates between +300 MN/m2 and -150 MN/m2. Determine the value of minimum ultimate strength according to Modified Goodman and Soderberg relations.

What are the primary causes of stress concentration in machine components? Explain with suitable examples.

A component machined from a plate made of steel 45C8 (Sut = 630 N/mm2) is subjected to a completely reversed axial force of 50 kN. The expected reliability is 90% and factor of safety is 2. Determine the size of the plate with stress concentration and notch sensitivity considerations.

Explain the design procedure for shafts subjected to combined bending and torsion, including equivalent bending moment and equivalent twisting moment and when they are used.

Determine the required diameter of a solid steel shaft transmitting 75 kW power at 300 rpm with a bending moment of 4 kN-m due to pulley loads using maximum shear stress theory. Take allowable shear stress as 60 MPa.

Design a helical compression spring for an axial load of 2500 N with a deflection of 40 mm. Take spring index 6, allowable shear stress 400 MPa and modulus of rigidity 80 GPa. Find wire diameter, mean coil diameter, number of active coils, free length and pitch.

Explain fatigue loading in springs and discuss spring failure.

Explain the construction and design procedure of rope, band and block brakes with neat sketches.

A band brake acts on a drum of diameter 600 mm rotating at 250 rpm and absorbs 20 kW power. The coefficient of friction between band and drum is 0.3 and angle of contact is 270 degrees. Determine the tight-side and slack-side tensions in the band.

Explain the design procedure of journal bearings.

Compare journal bearings and rolling contact bearings with suitable examples.

Write short notes on any two: (a) Static and dynamic load capacities of rolling bearings (b) Bearing life and reliability (c) Types of rolling contact bearings.