Finite element analysis of welding pressing force for aluminum alloy middle roof plate of urban rail transit train

During the welding process, the aluminum alloy middle roof plate of an urban rail transit train will generate welding stress under restriction of the clamper as a result of heat deformation. Meanwhile, welding stress raises certain requirements on fixture technique, and the clamping force of the fixture can reduce the deformation of the workpiece. The support reaction generated at the position of the fixture during the welding process can easily cause fatigue failure of the fixture. In this article, the welding process of the middle roof plate is simulated by adopting thermal mechanical analysis to acquire the support reaction at the position of the fixture during the welding process. The pressing situation of the fixture is improved by the increase in the number of fixtures, and actual verification is performed through the welding process test.