Somnath Chattopadhyay

Fatigue Evaluation Incorporating Multiaxiality of Stress States

In this work the effects of multiaxiality on the fatigue evaluation by the ASME Boiler and Pressure Vessel Code procedures have been assessed. The conservatism associated with the Ke factor has been critically appraised for fatigue evaluation using a design example of a feed water nozzle subjected to pressure and thermal fluctuations. A fictitious stress concentrator is applied to account for the ratio of the peak stress to the stress linearized through the thickness of the section under consideration. The effect of the traxiality of the stress distribution has also been assessed using the same design example for fatigue evaluations. Additional analytical and experimental studies have been recommended to study these important critical factors for fatigue assessment.Copyright