In this task, a numerical study is utilized to determine the residual stress of the flash butt joint in the UIC60 rail. To accurately predict critical locations of tensile residual stress, the influence of phase transformation is considered in the simulation. To reduce the possibility of failure in the welded rail, the most effective parameters of the flash butt welding during and after the process are optimized to decrease critical tensile residual stresses in the weldment. To this end, a coupled procedure by considering the imperialist competitive algorithm (ICA) in Matlab and process modeling in the Python code of Abaqus software is performed. In this procedure, time duration and heat input at each step and upsetting force are considered as welding machine parameters, and the cooling rate is assumed as post welding factor. Using the effectiveness of the ICA method, in nonlinear and huge multi parameters and steps problems, the optimum values of considered factors in terms of reducing the tensile residual stress in butt joint are obtained. The optimum values and effectiveness of each controlling parameter on the maximum and the pattern of tensile residual stress to diminish the failure of the butt welded rail under service loads are discussed.

在此任务中，将通过数值研究来确定UIC60导轨中对接接头的残余应力。为了准确预测拉伸残余应力的关键位置，在模拟中考虑了相变的影响。为了减少焊接轨发生故障的可能性，优化了过程中和过程后的快速对接焊接的最有效参数，以减少焊接件中的临界拉伸残余应力。为此，通过考虑Matlab中的帝国主义竞争算法（ICA）和Abaqus软件的Python代码中的过程建模来执行耦合过程。在此过程中，将持续时间和在每个步骤输入的热量和up锻力视为焊接机参数，并将冷却速率视为焊后系数。利用ICA方法的有效性，在非线性和巨大的多参数和阶跃问题中，获得了在减小对接接头的拉伸残余应力方面考虑因素的最佳值。讨论了每个控制参数在最大值上的最佳值和有效性，以及在工作载荷下减小对接焊轨故障的拉伸残余应力模式。