基于结构应力法的未焊透焊接接头疲劳强度评估

Fatigue Strength Evaluation of Incomplete Penetration Welded Joints Based on Structural Stress Method

研究了节点力法计算结构应力的计算过程,给出了结构应力的工程计算方法。考虑焊根未焊透缺陷对焊缝处结构应力的影响,提出一种根据焊缝等级及未焊透尺寸的结构应力计算板厚修正方法,通过建立未含焊根未焊透缺陷的焊缝有限元模型,获取未焊透焊缝处的结构应力,并应用该计算方法对某型地铁转向架焊接构架进行疲劳强度计算。计算结果表明,考虑焊缝根部未焊透初始缺陷,构架疲劳强度满足相关标准要求,验证了计算方法的可行性。

The calculation process of structural stress by node force method is studied,and the engineering calculation method of structural stress is given.Considering the influence of incomplete penetration defects on the structural stress at the weld,a method for calculating the structural stress of the plate thickness correction according to the weld grade and the incomplete penetration size is proposed.By establishing the finite element model of the welded joint without incomplete penetration defects,the structural stress at the incomplete penetration weld is obtained.Using this method,the fatigue strength of the welded frame of a subway bogie is calculated.The results show that considering the initial defect of welding and incomplete penetration,the fatigue strength of the frame meets the requirements of relevant standards,and the feasibility of the above calculation method is also verified.