Numerical evaluation of residual stress redistribution in welded bridge

The stress fields in a steel bridge girder under cyclic loads were calculated by elastic-plastic finite element 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.