An experimental study of simplified methods for the prediction of the deformation of structures subject to severe cyclic thermal loading

Abstract

The paper describes a set of thermal shock experiments on copper plates between room temperature and 250°C. The experimentally observed creep rates are compared with the predictions of two alternative simplified methods of analysis. The first involves rapid and slow cycle solutions which are computed using finite elements for two constitutive equations derived from the same constant stress data. The second involves upper bounds derived from shakedown solutions. It is shown that conservative results can be computed provided an appropriate relationship between average strain rate and cyclic stress history is known. The experimental data shows a sharp transition from a rapid cycle to a slow cycle condition as the load is increased above the high temperature shakedown limit.