高速列车底架焊接变形的超声波法应力分析

基于单轴应力下声弹性理论,针对现有临界折射纵波应力测量方法测试区域大的缺点,提出声程差方法,克服了应力分辨率和应力场分辨率的矛盾,在当前探头制造以及超声传播时间测量精度水平下,提高了应力场空间分辨率,能够更好地获得非均匀应力场的应力梯度;使用该方法对某型高速列车底架焊接变形进行了生产现场的应力测量;对比底架上变形合格与不合格部位的应力分布,并根据应力状况计算了变形超量,指出了导致变形的原因,为后期调修提供了可靠的依据.结果表明,该方法适用于生产现场的应力评估,对焊接结构质量监控有着重要意义.

Welding residual stress analysis of high-speed train undercarriage deformation by ultrasonic method

Ultrasonic propagation differential method based on critical wave Lcr acoustic-elastic effect in the condition of uniaxial stress state was proposed. It raised the spatial resolution of Lcr wave stress measurement to a higher level. It was applicable in the evaluation of welding residual stress,which was a gradient stress field. Residual stress distribution in an undercarriage of high speed train with welding deformation was surveyed by this method in manufacturing shop. Residual stress in both quality and sub-quality areas were obtained and compared. The source of the contraction distortion was confirmed,and it provided reference to the working out of the shape-righting scheme.