Abstract: To solve the connection problems of dissimilar materials in steel-aluminum hybrid car body, the steel and aluminum sheets with both thicknesses of 1.5mm were chosen as research objects, and the numerical simulation and experimental research were carried out to study the feasibility of mechanical clinching. The validity of simulation model was verified by experiment. On this basis, the connecting features of steel-aluminum sheets with different strength grades were investigated. The results showed that the place order of sheets had a significant influence on joint formation. To obtain high-quality joints concerning shear and tensile strength, the sheet with lower yield strength should be the upper sheet, and the yield strength of the two sheets should be as closer as possible. Through multi-objective optimization of approximation models for neck thickness and undercut of joints, the optimal solution sets were obtained by matching material type and sheet thickness of steel-aluminum sheets.

Key words: steel-aluminum hybrid, mechanical clinching, numerical simulation, matching laws, multi-objective optimization, automobile industry

摘要： 为解决钢铝混合车身结构中钢和铝异种材料间的连接问题，以厚度均为1.5 mm的铝合金和高强度钢板为研究对象，对其压力连接的可行性进行了数值模拟与实验研究。在实验验证仿真模型正确的基础上，对不同强度等级钢铝板材压力连接的特点进行了仿真分析，结果表明，板料放置顺序对连接点的形成有重要影响，应以屈服强度较低的板料为上板料，且钢铝板材的屈服强度应尽量接近，以保证得到高质量的连接点。通过对连接点颈厚值和自锁值近似模型的多目标优化，得到了材料类型及厚度组合匹配的优化解集。

关键词: 钢铝混合, 压力连接, 数值模拟, 匹配规律, 多目标优化