复杂环境下的三维疲劳断裂

 以三维弹塑性断裂理论为基础,对复杂载荷、复杂环境作用下的金属材料和结构的疲劳、断裂的若干关键问题进行了概要分析。给出了由材料性能试验的标准试样结果预测结构中一般形态缺陷的三维破坏的最新结果,获得了对不同载荷条件下腐蚀疲劳裂纹扩展的统一描述,介绍了由裂纹扩展基准曲线预测谱载腐蚀疲劳裂纹扩展寿命的最新进展,对结构服役寿命/日历寿命研究方法作了探讨。

REE-DIMENSIONAL FATIGUE FRACTURE IN COMPLEX ENVIRONMENTS

Some important problems in fatigue fracture of metal materials and structures under complex loading conditions and corrosion environments are analyzed on the basis of three dimensional elastic plastic fracture theory and experimental data base. Special emphases are given on corrosion fatigue crack growth, which is shown to be independent of the stress ratio and geometry of specimens when represented by use of the three dimensional theory. It is also shown that the limited stress life curve of material with different initial defect sizes is in linear relation in the log log coordinates. The prediction of the whole fatigue life of structures and the calendar life of machines are discussed along this line.