Numerical simulation–based optimization of clinching processes for high-strength steel sheets

Abstract

The choice of materials for car bodies varies significantly, driven by the dual objectives of minimizing body weight to improve fuel efficiency and enhancing passive safety for occupants. To integrate these diverse materials, a variety of joining techniques are used, including resistance spot welding, mechanical fastening, and adhesive bonding. The selection of materials for car body production is a critical determinant of vehicle performance, safety, manufacturing efficiency, and environmental impact. The car body-in-white (BIW), which serves as the vehicle's structural framework, must meet a diverse set of requirements, including a high strength-to-weight ratio, energy-absorption capacity during crashes, formability, corrosion resistance, and cost-effectiveness. This necessitates the use of a combination of materials, predominantly various grades of steel, along with aluminum alloys, polymers, and composites. Numerical simulations in the process of optimizing clinched joints represent an extremely effective tool that allows us to shorten the time of technology development and reduce the number of time-consuming and financially demanding experimental tests. However, the simulation outputs must be systematically verified and validated against experimental results. Only the combination of a suitable assembly and a reliably functioning numerical model with thorough experimental verification can lead to a technological solution that is operationally safe, secure and economically optimized at the same time. At the same time, the set of knowledge created in this way enables the systematic optimization of process parameters and increases the transferability of the obtained results to industrial practice.