文献类型：期刊文献

英文题名：Enhanced fatigue damage under cyclic thermo-mechanical loading at high temperature by structural creep recovery mechanism

作者：Cho, Nak-Kyun[1];Chen, Haofeng[1,2];Boyle, James T.[1];Xuan, Fu-Zhen[2]

机构：[1]Univ Strathclyde, Dept Mech & Aerosp Engn, Glasgow G1 1XJ, Lanark, Scotland;[2]East China Univ Sci & Technol, Sch Mech & Power Engn, Shanghai 200237, Peoples R China

年份：2018

卷号：113

起止页码：149

外文期刊名：INTERNATIONAL JOURNAL OF FATIGUE

收录：;EI(收录号：20181605031356);WOS:【SCI-EXPANDED(收录号:WOS:000437373300014)】；

基金：The authors gratefully acknowledge the support of the University of Strathclyde and East China University of Science and Technology during the course of this work. Supports from National Science Foundation of China (51605165, 51475167), National Key Research and Development Program of China (2016YFC0801905), and the '111 project' are also greatly acknowledged.

语种：英文

外文关键词：Creep-cyclic plasticity; Stress redistribution; Creep enhanced plasticity; Creep ratchetting

摘要：Creep-cyclic plasticity of a benchmarked holed plate subjected to thereto-mechanical loading is investigated by means of nonlinear finite element analysis. From the analyses, a structural creep recovery response is found within a dwell period, which has serious repercussions on structural integrity. The structural creep recovery can take place by reversing the creep stress in sign during the stress relaxation due to the creep stress redistribution, consequently enhancing unloading plasticity which causes a substantial increase of total strain range within a cycle. Based on this critical observation, further analyses and discussions are provided to investigate the root cause of this precautious structural response. Various cyclic loadings with a dwell at the peak thermal load are analysed to define factors influencing the structural creep recovery mechanism, and to investigate how the mechanism affects the lifetime of the structure. To show the effectiveness of the structural creep recovery mechanism under cyclic loading, Chaboche nonlinear kinematic hardening model is adopted. Limitations of applying elastic follow-up in predicting creep strains and appropriate creep-fatigue damage calculation methods are discussed in the presence of this structural creep recovery mechanism. This research work confirms that when a structure experiences the structural creep recovery it can reduce creep damage, nevertheless the structure may experience significant fatigue damage due to creep enhanced plasticity.