轨道车辆型材结构搅拌摩擦焊残余状态研究

Residual State of Friction Stir Welding of Rail Vehicle Profile Structures

目的研究轨道车辆中典型的箱型和V筋结构型材搅拌摩擦焊残余状态。方法采用顺序热力耦合方法进行了搅拌摩擦焊残余应力及变形的仿真研究。结果给出了上下壁板焊缝区域的残余应力大小及分布规律,阐述了两种结构的横向和纵向残余变形特征。对V筋结构型材,分析了不同筋板角度对焊接残余状态的影响。结论残余应力方面,主要表现为纵向残余应力,上下壁板两条焊缝的残余应力峰值相近,高应力分布区域宽度差别较大。残余变形方面,箱型结构呈马鞍形,V筋型材呈下凹形。V筋型材筋板夹角的变化对残余应力没有显著影响。筋板角度增大,纵向残余变形减小而横向残余变形增大。

The paper aims to study residual states of friction stir welding of rail vehicle box and V bar profile structures. Simulation study was carried out based on the sequential thermo-mechanical coupling method. The value and distribution of residual stress in weld areas located at the top and bottom panel were analyzed in details. The distribution characteristics of transverse and longitudinal residual deformation of two structures were expounded, and influence of V bar angle on the residual state was discussed. The residual stress is mainly shown as the longitudinal residual stress, the peak value of the residual stress of the two welds in the upper and lower panels is similar, and the width of the high stress distribution is different. In terms of residual deformation, the box structure is saddle shaped and the V bar profile is concave. The change of the angle between the V bar profiles has no significant effect on the residual stress. With the increase of bar angle, the longitudinal residual deformation decreases and the transverse residual deformation increases.