摘要
等效缺口应力法作为焊接疲劳分析的一种局部方法,不仅克服了焊接结构名义应力难以确定和焊根结构应力无法定义的困难,而且能够反映焊接局部后处理对焊接接头疲劳强度的影响,因此近年来备受关注。该文建立了典型焊接接头的三维缺口应力模型,对焊趾根部的缺口应力集中系数进行了求解;通过对对接接头和纵向角接头在焊后未处理(AS-weld)和超声喷丸处理(UPT)两种状态下的疲劳试验数据进行分析处理,获得了两种焊接接头在缺口应力系统下统一的S-N曲线,并与目前国际焊接学会所推荐的具有相同存活率的疲劳寿命曲线(IIW:m=3,FAT=225)进行比较,结果表明,该曲线具有更高的疲劳等级和更低的斜度。
The notch stress method （NSM） is a local method of welding fatigue analysis, which has attracted much attention in recent years. Traditionally, the nominal stresses in welded structures are difficult to determine and the weld root stress cannot be defined, but NSM can not only successfully overcome these problems but also assess the effects of welded joint fatigue strength with local welding post-processing. In this paper, 3D notch stress models of typical welded joints are presented to solve the notch stress concentration factors （nSCF） in a weld toe. Some fatigue test data from butt joints and longitudinal fillet joints are referenced from literature, which include two conditions： As-weld and ultrasonic peening treatment（UPT）; then unified S-N curves under notch stress system are obtained by combining the nSCF and fatigue data. Compared to the referenced fatigue-life curve of International Institute of Welding （IIW： m=3, FAT=225） at the same survival probability, it shows that these fitting curves have higher fatigue classes and shallower slopes.
出处
《工程力学》
EI
CSCD
北大核心
2016年第6期209-214,249,共7页
Engineering Mechanics
基金
国家自然科学基金项目(51205324)
