基于XFEM的复杂应力状态下疲劳裂纹扩展分析  

Analysis of fatigue crack propagation under complex stress state based on XFEM

作　　者：墨馨遥 薛凤梅 刘毅[1] 焦泽瑞 MO Xin-yao;XUE Feng-mei;LIU Yi;JIAO Ze-rui(School of Materials Science and Engineering,Taiyuan University of Technology,Taiyuan 030024,China)

机构地区：[1]太原理工大学材料科学与工程学院,山西太原030024

出　　处：《塑性工程学报》2022年第1期177-182,共6页Journal of Plasticity Engineering

基　　金：国家自然科学基金资助项目(51905371)。

摘　　要：以AZ31镁合金为研究对象,基于扩展有限元方法,对板件上0°、80°和90°这3种不同角度裂纹在9种不同应力状态交替载荷作用下的扩展形态进行数值模拟分析。结果表明,不同应力状态交替载荷作用下,相同角度的疲劳裂纹扩展形态不同;相同应力状态交替载荷作用下,不同角度的疲劳裂纹扩展形态也不同;疲劳裂纹在受到交替拉应力作用时更容易发生扩展,裂纹扩展的方向与垂直于初始裂纹的拉伸分应力有关,裂纹一般为张开型/I型;在受到交替压应力和剪应力作用时,裂纹一般为滑移型/II型;裂纹完全开裂时,疲劳裂纹的长度与循环次数成正比。Taking AZ31 magnesium alloy as the research object,based on the extended finite element method,the propagation patterns of cracks with three different angles of 0°,80°,and 90° on the plate in nine different stress states alternating loads were simulated and analyzed by numerical simulation.The results show that the fatigue crack propagation patterns with the same angle are different in different stress states alternating loads.Under the same stress state alternating load,the fatigue crack propagation patterns of different angles are also different.Fatigue cracks are more likely to propagate under tensile alternating stress.The direction of crack propagation is related to the tensile component stress perpendicular to the initial crack,and cracks are generally opening type/I type.When subjected to compressive alternating stress and shear stress,the cracks are generally sliding type/Ⅱ type.When the crack cracks completely,the length of fatigue crack is proportional to the number of cycles.

关 键 词：扩展有限元方法 应力状态 疲劳 裂纹扩展 AZ31镁合金 

分 类 号：TG146[一般工业技术—材料科学与工程]