RATCHETTING CHARACTERISTICS OF 316FR STEEL AT HIGH-TEMPERATURE, PART-II - ANALYSTS OF THERMAL RATCHETTING INDUCED BY SPATIAL VARIATION OF TEMPERATURE

On the basis of the material characteristics discussed in Part I, ther mal ratchetting of 316FR steel cylinders subjected to the axial variat ion of temperature is analyzed by implementing in a finite element met hod three kinds of models, i.e. the elastic-perfectly plastic model, t he Armstrong-Frederick model, and the first version of the Ohno-Wang m odel. The latter two models are specified in two forms, i.e. the combi ned hardening form verified in Part I and the kinematic hardening form with isotropic hardening neglected. It is shown that the analysis dep ends greatly on the models examined while it is influenced relatively little by the neglect of isotropic hardening, and that the Ohno-Wang m odel, which can express the closure of stress' and strain hysteresis l oops, gives good simulations to experiments in the two cases of long a nd short travel distances of temperature distributions. (C) 1998 Elsev ier Science Ltd. All rights reserved.