Abstract: In the process of automotive product development, preliminary virtual assessment for each production stage can identify risks in advance, shorten the overall project development cycle, and reduce product development cost. This paper applies the finite element simulation technology to the handling process of the body-in-white assembly, predicts and analyzes the risk point of the drop deformation, and finds out the deformation risk near the positioning hole of the lower assembly. According to the analysis results, the optimization and improvement plan is proposed and verified by simulation. The verification results show that the product design optimization and the improvement of the connection process can effectively reduce the stress of the parts during the placement process, avoid the permanent placement deformation defect, ensure the strength of the vehicle and the positioning accuracy of the lower assembly, and reduce the cost of post-repair and debugging. It is significant to improve the level of intelligent manufacturing of car body and reduce manufacturing cost by identifying manufacturing quality risks in the early product design stage, guiding product design, and avoiding the flow of quality risks to the physical vehicle manufacturing stage.

Key words: Car body lower assembly; Drop deformation; Finite element simulation; Structure optimization; Virtual assessment analysis

摘要： 在汽车产品开发过程中，针对各生产阶段进行前期虚拟评估可以提前识别风险，缩短 整体项目开发周期，减少产品开发成本。文章将有限元仿真技术应用于白车身总成搬运过程， 围绕落位变形这一风险点进行预测和分析，发现底板定位孔附近存在的变形风险，根据分析 结果提出优化改进方案，并进行仿真验证，验证结果表明，通过产品设计优化及连接工艺改 进可以有效降低落位过程零件应力，避免产生永久落位变形缺陷，保证整车强度与底板定位 精度，减少后期修模调试成本。文章表明，通过在产品早期设计阶段对制造质量风险进行识 别，指导产品设计，避免质量风险流到实物造车阶段，对于提升车身智能制造水平，降低制 造成本具有重要意义。

关键词: 车身底板；落位变形；有限元仿真；结构优化；虚拟评估