Research on welding deformation control technology of battery electric vehicle framed aluminum body

The welding process of aluminum (Al) alloy car body has problems such as poor weld quality, low welding coefficient, and large welding deformation. This paper mainly focuses on material accuracy design, lap structure design, simulation, and process manufacturing to break through the precision control problems caused by welding deformation of battery electric vehicle Al alloy car body. First, the 209 key functional dimensional chains of Al body-in-white are analyzed and decomposed to component and profile tolerance dimensions step by step. Moreover, the differences of vertical butt, bevel butt, and plug structures are studied and joint matching is implemented in a targeted manner. Subsequently, through welding deformation simulation analysis and welding sequence optimization, the body-in-white welding process and tooling fixtures are guided and designed to ensure that the dimensional accuracy of the Al body is controlled to ±2 ​mm in all aspects. Finally, the design of the whole vehicle arrangement of mechanical, human-machine, and major components is carried out, and an all-Al framed battery electric vehicle lightweight platform with different sizes and ranges is innovatively created. The difficulties such as the contradiction between power battery size and arrangement space, unreasonable arrangement position, and load distribution are solved.