Linear matching method on the evaluation of plastic and creep behaviours for bodies subjected to cyclic thermal and mechanical loading

On the basis of the previously proposed Linear Matching Method (LMM), a new LMM model and its corresponding numerical procedure are developed in this paper to allow for the evaluation of plastic, creep and ratchet strains of structures subjected to a general load condition in the steady cyclic state. The constant and varying residual stress fields associated with differing mechanisms are obtained as well as the steady cyclic stress state of the whole component for further structural design and assessment. The total strain range for use in fatigue assessment, including the effect of creep and plastic strains, is obtained. A typical example of 3D holed plate subjected to cyclic thermal load and constant mechanical load is analysed here in detail to verify the applicability of the proposed numerical technique. The LMM results in the paper are compared with those obtained by ABAQUS step-by-step inelastic analyses. This comparison demonstrates that the LMM has both the advantage of programming method and the capacity to be implemented easily within a commercial finite element code, in this case ABAQUS. The LMM provides a general-purpose technique for the evaluation of creep/fatigue interaction in the steady cyclic state. Copyright 2006 John Wiley & Sons, Ltd.