考虑残余应力的焊接结构多轴疲劳准则  

Multiaxial fatigue criteria of welded structures considering the residual stress

作　　者：周昊[1] 刘英芳 刘刚[1] 黄一[1] 

机构地区：[1]大连理工大学船舶工程学院,大连116024 [2]大连船舶重工集团设计研究所,大连116005

出　　处：《焊接学报》2017年第11期41-46,共6页Transactions of The China Welding Institution

基　　金：国家自然科学基金资助项目(51179027;51379031);国家重点基础研究发展计划资助项目(2011CB013704)

摘　　要：因随机波浪载荷及焊接残余应力的存在,海洋工程焊接结构的疲劳失效受多轴疲劳机理控制,然而目前的多轴疲劳准则对焊接残余应力关注较少,针对上述问题文中通过将不包含焊接残余应力的有限元计算应力场与焊接残余应力场线性叠加作为多轴疲劳寿命计算应力场,提出了一种基于临界面法的多轴疲劳寿命预测准则,通过对国际上已公开发表的疲劳试验数据进行有限元分析并与多轴疲劳准则MWCM对比,证明文中方法比MWCM具有更高的准确性,对于非比例载荷作用下的疲劳寿命预测效果尤为显著,同时证明了文中方法可以有效考虑焊接残余应力的影响.Welded structures in ocean engineering are always in multiaxial fatigue state,which are subjected to random wave loads and welding residual stresses. However,there is little concern about welding residual stresses in current multiaxial fatigue criteria. Aiming at the problem above,a new multiaxial fatigue criteria basing on the critical plane method is proposed.This paper put the linear superposition of measured residual stress field and hot spot stress field extracted from finite element model excluding residual stresses together to calculate the multiaxial fatigue damage. By numerically analyzing a series of published fatigue data,the new criteria proves feasible for the multiaxial fatigue life estimation and more accurate than the modified W9 hler curve method. The accuracy of proposed multiaxial fatigue criteria for fatigue life prediction under non-proportional loading is particularly significant. Meanwhile,the new criteria proves high-efficiency in considering the influence of welding residual stresses on fatigue life.

关 键 词：临界面法 焊接结构 残余应力 多轴疲劳 非比例载荷 

分 类 号：TG405[金属学及工艺—焊接]