article published yes Pia Katharina Kaimann author 44935 Nico Ritter author Mathias Bobbert author 7850 Gerson Meschut author 320560000-0002-2763-1246 43 department 157 department TRR 285: Methodenentwicklung zur mechanischen Fügbarkeit in wandlungsfähigen Prozessketten project TRR 285 - Project Area C project TRR 285 - Subproject C02 project To reduce CO₂ emissions, the automotive industry is adopting multi-material structures. Fusion-based joining reaches its limits for aluminium–steel due to brittle intermetallic phases and mismatched thermophysical properties; therefore, mechanical joining (e.g., SPR) is used. Though conventional SPR requires tool changes for different stack-ups. Versatile self-piercing riveting (V-SPR) addresses this with an extended punch actuator and a multi-range-capable rivet (Kappe in PERD16:363–378, 2022), enabling joints up to 600 MPa across varying thicknesses without retooling. With the use of ultra-high-strength steels up to 1000 MPa, optimisation is required. This study quantifies how rivet shank geometry affects joint formation using a design of experiments and validated 2D axisymmetric FE simulations. The optimum depends strongly on the material system. For CP1000–EN AW-6014, maximum interlock f is predicted for a medium shank thickness of about 0.73 mm, a small internal foot radius of 0.620 mm, and a deeper drill depth of 3.136 mm, yielding f fc =0.4503 mm with a desirability of 0.954. For EN AW-6014–EN AW-6014, the optimum shifts to a thinner shank of 0.670 mm, a larger internal foot radius of 0.820 mm and a shallow drill depth of 2.30 mm, giving ffc = 0.3023 mm with a desirability of 1.0. A compromise geometry of 0.713 mm shank thickness, 0.776 mm internal foot radius and 2.755 mm drill depth achieves ffc = 0.3641 mm for CP1000–aluminium and ffc = 0.1851 mm for aluminium–aluminium with an overall desirability D = 0.6378, expanding V-SPR to ultra-high-strength steel–aluminium joints while maintaining aluminium joinability. Springer Science and Business Media LLC2026 eng 2731-656410.1007/s44245-026-00221-y 51 Kaimann, Pia Katharina, et al. “Influence of the Shank Geometry on the Joint Formation of the Versatile Self-Piercing Riveting of Ultra-High-Strength Steel-Aluminium and Aluminium-Aluminium Assemblies.” <i>Discover Mechanical Engineering</i>, vol. 5, no. 1, 43, Springer Science and Business Media LLC, 2026, doi:<a href="https://doi.org/10.1007/s44245-026-00221-y">10.1007/s44245-026-00221-y</a>. @article{Kaimann_Ritter_Bobbert_Meschut_2026, title={Influence of the shank geometry on the joint formation of the versatile self-piercing riveting of ultra-high-strength steel-aluminium and aluminium-aluminium assemblies}, volume={5}, DOI={<a href="https://doi.org/10.1007/s44245-026-00221-y">10.1007/s44245-026-00221-y</a>}, number={143}, journal={Discover Mechanical Engineering}, publisher={Springer Science and Business Media LLC}, author={Kaimann, Pia Katharina and Ritter, Nico and Bobbert, Mathias and Meschut, Gerson}, year={2026} } P.K. Kaimann, N. Ritter, M. Bobbert, G. Meschut, Discover Mechanical Engineering 5 (2026). Kaimann, P. K., Ritter, N., Bobbert, M., &#38; Meschut, G. (2026). Influence of the shank geometry on the joint formation of the versatile self-piercing riveting of ultra-high-strength steel-aluminium and aluminium-aluminium assemblies. <i>Discover Mechanical Engineering</i>, <i>5</i>(1), Article 43. <a href="https://doi.org/10.1007/s44245-026-00221-y">https://doi.org/10.1007/s44245-026-00221-y</a> Kaimann PK, Ritter N, Bobbert M, Meschut G. Influence of the shank geometry on the joint formation of the versatile self-piercing riveting of ultra-high-strength steel-aluminium and aluminium-aluminium assemblies. <i>Discover Mechanical Engineering</i>. 2026;5(1). doi:<a href="https://doi.org/10.1007/s44245-026-00221-y">10.1007/s44245-026-00221-y</a> P. K. Kaimann, N. Ritter, M. Bobbert, and G. Meschut, “Influence of the shank geometry on the joint formation of the versatile self-piercing riveting of ultra-high-strength steel-aluminium and aluminium-aluminium assemblies,” <i>Discover Mechanical Engineering</i>, vol. 5, no. 1, Art. no. 43, 2026, doi: <a href="https://doi.org/10.1007/s44245-026-00221-y">10.1007/s44245-026-00221-y</a>. Kaimann, Pia Katharina, Nico Ritter, Mathias Bobbert, and Gerson Meschut. “Influence of the Shank Geometry on the Joint Formation of the Versatile Self-Piercing Riveting of Ultra-High-Strength Steel-Aluminium and Aluminium-Aluminium Assemblies.” <i>Discover Mechanical Engineering</i> 5, no. 1 (2026). <a href="https://doi.org/10.1007/s44245-026-00221-y">https://doi.org/10.1007/s44245-026-00221-y</a>. 653732026-04-08T08:25:32Z2026-04-08T08:34:40Z