移动车载下钢桥焊接箱梁残余应力安定性分析

Numerical Evaluation of Welding Residual Stress Shakedown in Steel Bridge Girder by Moving Loads

采用弹塑性有限元方法,模拟在周期荷载作用下钢桥焊接箱梁残余应力场的安定行为。研究表明,在周期荷载作用下,焊接箱梁的残余应力场会发生重分布,残余应力幅值会相应减小;在等幅循环荷载作用下,残余应力的重分布仅局限于第一个循环;在变幅载荷作用下,残余应力的松弛行为取决于最大幅值的循环载荷。根据上述规律,研究了钢桥焊接箱梁在移动列车荷载作用下的残余应力安定行为,获得了重分布的焊接残余应力场。

The stress fields in a steel bridge girder under cyclic loads were calculated by elastic-plastic finite dement method. It is shown that the load application on the pre-stressed component produces a reassessment of the stress field and, in particular, a relaxation of the maximum stress; the relaxation process is almost limited to the first cycle; the degree of the residual stress relaxation is mainly controlled by the cyclic loading with the largest amplitude under variable amplitude loading. Based on the laws above, the shakedown behavior of steel girder under moving train load was analyzed and the redistributed residual stress field was acquired.