Question

QUESTION 3
(a) A crankshaft in a diesel engine fails. Examination of the crankshaft reveals no plastic deformation. The fracture surface is smooth. In addition, several other cracks appear at other locations in the crankshaft. What type of failure mechanism occurred?
(b) A titanium pipe used to transport a corrosive material at 400°C is found to fail after several months. How would you determine the cause for the failure?
(c) Your company has produced several thousand shafts that have
a fatigue strength of 20,000 psi. The shafts are subjected to high bending loads during rotation. Your sales engineers report that the first few shafts placed into service failed in a short period of time by fatigue. Design a process by which the remaining shafts can be
salvaged by improving their fatigue properties.

Answer 1

3.a)

The diesel uses the compression to ignite the fuel mixture entering the cylinder & The Crankshatt in rotating in the cylinder for production. The type of failure mechanism is faitque. The crack are most prone to diesel engine to due to extreme burning of the fuel-air mixture.

b.) Corrosive restation decrease with time. Assuming pipe is continuously be used for transporting the material 400 °C. .The resistance decrease with time.

.c) Fatigue strength of 20,000 psi and factor affecting rotating motion due which Enginee starts its function. To improve the fatigue strength by smoothing the surface. By using a high-pressure coating to hold the continuous rotating and can be used for a longer time periodt.