汽车钢制车轮组合焊接的残余应力场研究

The wheel is one of the most severely loaded parts in a vehicle. The structural safety of wheel is vital for the safety of automobile driving, and the traffic accidents caused by broken wheel occur from time to time. The steel wheel in the commercial vehicle is usually made of prefabricated spoke and rim that are assembled and welded. The welding toe is the part most prone to fatigue cracking on the wheel. The total stress of this part is the superposition of welding residual stress and working stress. Since the configuration of the wheel is complicated and the stress distribution is uneven, it is difficult to measure the overall welding residual stress of the wheel through experimental methods. In order to accurately predict the wheel stress and carry out accurate lightweight design, it is necessary to accurately predict the welding residual stress distribution. Aiming at this problem, a thermal-mechanical-phase field coupling simulation model of steel wheel considering the phase transformation of the metal during the welding process is established. And the accuracy of heat input of the heat source model is verified through comparing the shape of the molten pool of simulation and experiment. Then the temperature filed from the simulation and experiment is compared to verify the correctness of simulation model. The welding residual stress measured by the blind hole method indicates that the residual stress field obtained by the simulation method has high accuracy. It is also found that the residual stress at the weld toe is distributed periodically along the circumferential direction, and the welding residual stress of weld toe opposite vent hole is smaller than that opposite wheel disk. The interference fit has no obvious effect on the welding residual stress at the welding toe of the rim. The research on the residual stress field of the combined welding of automotive steel wheel in this paper is helpful to obtain the real stress distribution of the wheel under the consideration of welding residual stress, and plays a vital role in the lightweight of the wheels.