Incorporation of strain hardening and sheet thinning effects during forming process for an accurate prediction of buckling loads on sheet metal axle parts

In this competitive automotive world, shorter development time and quicker time to market for new models are vital to product success. This can be achieved by digitalization, thereby avoiding over-design of parts and the need for physical prototypes, resulting in cutting down on material and development efforts respectively. In this study, the deviation of load carrying capacity of chassis sheet metal axle links in comparison with hardware testing and simulation results were investigated. A multi-step forming simulation is carried out, which involves simulating all stages of the forming process to accurately predict the plastic strains leading to material strain hardening and thickness distribution leading to thinning. The forming simulation is performed using the anisotropic material model Banabic-Barlat-Comsa (BBC) to capture the anisotropy effects. This model uses several coefficients to precisely characterize the yield surfaces, considering both uniaxial and biaxial yield stresses, as well as anisotropy coefficients. The output from the forming simulation, Equivalent Plastic Strains (EPS) and thickness data are mapped on to the FEA model as initial conditions for static strength calculation using a non-linear Finite Element (FE) solver. Conclusion: • The simulation results show a significant improvement with respect to the load carrying capacity with a deviation from the test results, less than 1% by including the forming effects. • This correlation builds confidence in the simulation results, leading to a reduction in development time, elimination of proto parts and ensures the parts are designed to meet performance requirement without being excessively robust. • This study highlights the importance of considering forming effects in simulations to achieve realistic and cost-effective designs in the automotive industry.