钛合金焊接结构疲劳寿命预测方法研究

Fatigue Life Method Research of Titanium Alloy Welding Structure

在钛合金焊接结构疲劳特性评估的当量应力集中系数法基础上,提出了有效当量应力集中系数,通过建立当量应力集中系数和有效当量应力集中系数的关系,把适合描述焊接结构的当量应力集中系数引入到局部应力应变法中评估疲劳寿命;在等幅谱下对TC4钛合金电子束焊接件疲劳寿命进行了试验,得到了其当量应力集中系数和有效当量应力集中系数;在随机载荷谱下对TC4钛合金电子束焊接件进行试验和局部应力应变法计算,检验了方法的有效性。

On the basis of using of equivalent stress concentration factor for analyzing fatigue performance of titanium alloy welding,the author advanced the method of effective equivalent stress concentration factor,then introduced equivalent stress concentration factor applicable to weldment into local stress-strain method by establishing the relationship of equivalent stress concentration factor and effective equivalent stress concentration factor. According to tests and synthetic analysis for the fatigue life of titanium alloy( TC4) electron beam weld panel was evaluated under constant amplitude,equivalent stress concentration factor and effective equivalent stress concentration factor were proposed. According to tests and local stress-strain method analysis for the fatigue life of titanium alloy( TC4) electron beam weld panel was evaluated under random amplitude,the conclusions were presented.