ASSIGNMENT PE/AE 200 FATIGUE

Part 1.

Research an account of an engineering component that has failed from fatigue. Write up a brief report (1 typed/2 written pages) containing all the relevant details.

Part 2.Describe what is meant by the following

1. Fatigue limit.

2. Fracture toughness.

3. Creep.

4. Intergranular fracture.

5. Ductile fracture.

Part 3.The fatigue data for a brass alloy are given as follows

STRESS AMPLITUDE (MN/m2)CYCLES TO FAILURE

1703.7 X 104

1481.0 X 105

1303.0 X 105

1141.0 X 106

921.0 X 107

801.0 X 108

741.0 X 109

(a) Make an S-N plot (stress amplitude verses logarithmic cycles to failure) using the above data.

(b) Determine the fatigue strength at 4 x 106 cycles of the brass alloy.

(c) Determine the fatigue life for 120 MN/m2.

Part 4.

(a) Cite five factors that might lead to scatter in fatigue life data.

(b) Briefly explain the difference between fatigue striations and beachmarks both in terms of size and origin.

(c) List four measures that may be taken to increase the resistance to fatigue of a metal alloy.