Thermal fatigue resistance of elastic-plastic bodies under surface temperature changes (Q1088514)

A rigorous elastic-plastic analysis allowing for a temperature-dependent yield condition is carried out in the present paper to determine the plastic strain of a semi-infinite solid subjected to uniform temperature changes at its surface. This leads to simple analytical and graphic procedures to evaluate the plastic deformation produced in a body of any shape by surface heating or cooling processes, provided that these processes are so fast - or that the thermal impedance of the body is so high - that all the temperature variations of the body are confined to within a thin layer near the body surface. The results are then applied to predict the occurrence of rupture by thermal fatigue at the body surface once its temperature variations are known. In particular, for heating and cooling cycles that occur entirely above or entirely below the initial temperature of the body, it is found that there is a limit in the magnitude of the temperature variations, below which no thermal fatigue will occur at the body surface, no matter how many times the cycle is repeated.