In the aluminum alloy body of rail vehicle

the floor is a typical welded structure of aluminum alloy profiles. And after welding

it is prone to occur large residual stress and welding deformation

such as bulging and twisting

which increases the difficulty of assembly of various components

and reduces the bearing capacity of the floor. In this paper

a thermal-mechanical coupled finite element model based on the thermal-elastoplastic method is established and calculated to gain the postweld residual stresses and the distribution of welding deformations of floor structure. And the simulated residual stresses are compared with experimental results

which shows a good agreement. Finally

the simulations of different welding sequence of floor structure are compared and analyzed

and the welding scheme with the minimum welding deformation or residual stress is obtained

which provides a guidance for the welding practice.