点焊接头疲劳研究综述

Overview of Fatigue Research of Spot Welded Joints

对点焊接头疲劳研究近几十年的发展进行全面的综述。从数值分析、试验分析、有限元分析和疲劳评估方法等4个方面系统梳理和综述点焊接头的疲劳研究成果,将点焊静态理论、局部应力、结构应力和断裂力学等数值分析方法进行归纳总结;从静态试验、拉剪疲劳试验、剥离试验和缺口试验等试验方法中研究点焊接头失效模式、失效机理和疲劳寿命;对8种点焊接头有限元模型的特点、建模方法、适用范围进行了对比综述,认为C_WELD和C_BAR模型适用于大型点焊结构中;对载荷-寿命法、名义应力法、热点应力法、等效结构应力法等多种点焊接头疲劳评估方法的适用条件、适用对象、评估效果等进行归纳总结,认为等效结构应力法值得在工程领域进行推广应用。最后对存在的问题和进一步研究方向进行评述和探讨,对点焊接头更深入的疲劳研究具有一定的指导和帮助。

The research on fatigue of spot welded joints in recent decades is summarized comprehensively.The achievements of research on fatigue of the spot welded joints are described systematically from 4 aspects,including numerical analysis,experimental analysis,finite element analysis,and fatigue assessment methods.The numerical analysis methods of spot welding such as static theory,local stress,structural stress and fracture mechanics are summarized.The failure mode,failure mechanism and fatigue life of spot welded joints are studied by test methods such as static test,tensile-shear fatigue test,peel test and notch test.The characteristics,modeling methods and applicable scopes of 8 kinds of finite element models of spot welding joints are compared and summarized,and the C_WELD model and C_BAR mode are considered to be suitable for large spot welding structures.The applicable conditions,applicable objects,and evaluation effect of various fatigue assessment methods for spot welded joints such as load-life method,nominal stress method,hot spot stress method,and equivalent structural stress method are summarized,and it is believed that the equivalent structural stress method is worthy of popularization and application in the field of engineering.Finally,the existing problems and further research directions are reviewed and discussed,which would provide some guidance and assistance for further research on fatigue of spot welded joints.