Creep analysis of surface-cracked plates by a creep line-spring method

The creep line-spring method proposed in this paper is based on the solutio ns for the following two problems: a creep crack under non-steady creep con dition; an elastic-plastic surface-cracked plate. For the problem of a non- steady creep crack, an engineering approach for estimating the load-line di splacement, crack-tip J and C integrals is presented by extending the engin eering approach for elastic-plastic fracture analysis to creep analysis. Fo r solving the elastic-plastic surface crack, a simplified elastic-plastic l ine-spring method is applied. These two approximate solutions are checked b y the finite element method. On the basis of the above two approximate meth ods, a creep line-spring method is proposed and the corresponding fundament al equations are established. The creep line-spring method is used to estim ate creep fracture parameters for three-dimensional cracks. In order to che ck its accuracy, several surface-cracked plates under uniform tension are a nalyzed by the creep line-spring method and by the three-dimensional finite -element method. The numerical results show that the creep line-spring meth od is in good agreement with the finite-element method and has the same acc uracy as the common elastic-plastic line-spring method.