By combining experimental SPR tests with a finite element (FE) model, the influences of top sheet thickness (T_t), bottom sheet thickness (T_b) and rivet length (L) on the joint formation mechanisms were systematically investigated in this study. Single factor experiments were firstly conducted to uncover the three joining parameters' effects on the joining results. Interrupted SPR tests were also performed to confirm the prediction accuracy of the FE model on the joint formation process. Then, the joint formation mechanisms were analyzed by numerically inspecting the events during the riveting process, including the sheet deformation behaviors, rivet shank flare behavior and formation of quality indicators. The results revealed that the joining parameters affected the interlock formation by directly altering the positions of two interlock boundaries. The rivet shank flare behavior was apparently affected by the T_t and T_b, but less influenced by the L. The formation of remaining bottom sheet thickness at the joint center (T_c) was significantly affected by the T_t and T_b. Rapid reduction of the T_c occurred before the top sheet was penetrated and after the rivet cavity was fully filled. Meanwhile, it is highlighted that the FE model is an excellent tool to analyze SPR joint formation.

通过将实验 SPR 测试与有限元 (FE) 模型相结合，顶板厚度 ( T _t )、底板厚度 ( T _b ) 和铆钉长度 ( L ) 的影响) 在这项研究中系统地研究了联合形成机制。首先进行单因素实验以揭示三个连接参数对连接结果的影响。还进行了间断 SPR 测试，以确认有限元模型对接头形成过程的预测准确性。然后，通过对铆接过程中发生的事件进行数值检测，分析了接头形成机制，包括板材变形行为、铆钉杆扩口行为和质量指标的形成。结果表明，连接参数通过直接改变两个互锁边界的位置来影响互锁的形成。T _t和T _b明显影响铆钉柄扩口行为，但受 L 的影响较小。在接头中心（T _c）处剩余底板厚度的形成受T _t和T _b显着影响。T _{c 的}快速降低发生在顶板被穿透之前和铆钉腔被完全填充之后。同时，强调有限元模型是分析 SPR 节理形成的绝佳工具。