关键词: 316L不锈钢, 低周疲劳, 非比例加载, 比例边界法, 强度因子, 无单元伽辽金法, 压电材料

Abstract: The tests were performed for 316L stainless steel under uniaxial and multiaxial nonproportional low cycle fatigue, and the microstructures in this material are observed. The micromechanism of dependence of nonproportional cyclic additional hardening and low cycle fatigue life on strain paths are analyzed. Based on the results of research of micromechanism, the new nonproportionality , of loading path is defined with the microstructural parameter-statistical mean value. The new life criterion of nonproportional low cycle fatigue under multiaxial loading is proposed.

Key words: 316L, Low cycle fatigue, Nonproportional loading, stainless steel, Element-free Galerkin method, Intensify factors, Piezoelectric material, Scaled boundary method