Power plant component design using creep and fatigue damage analysis

摘要

Structural analysis and design of power plant components requires us to take into account inelastic deformation and material damage processes under constant and variable loading and temperature conditions. The aim of this presentation is to introduce the constitutive models of creep and damage for advanced heat resistant steels. An emphasis is placed on the description of ductilebrittle transition of the damage mode depending on the applied stress level and the duration of the creep process. The model is applied to the lifetime prediction of a real power plant component. For this purpose a user-defined material subroutine is developed inside a general finite element code. The results of computations illustrate basic features of the stress redistribution and the damage evolution during isothermal loading cycle. Based on the obtained stress, strain and damage fields, we discuss the extensions of the proposed method to non-isothermal variable loading.