Investigation and Numerical Modelling of Snap Joints for the Automotive Crash Simulation

Amid increasing competition, ever stricter safety regulations and a growing range of products, the demand for effective virtual testing in the automotive industry is continuously rising. Nowadays, numerical simulations are an indispensable instrument in the crashworthiness analysis of motor vehicles. One particular modelling challenge is constituted by joining techniques. Among these, snap-fitting is rather underrepresented in research, compared to joining methods for bearing structures. At the same time, the technique is largely deployed in the automotive interiors and exteriors, carrying unquestionable significance for the safety of passengers and pedestrians alike. The present work lays out a methodical approach to the study of snap joints beyond textbook solutions in order to meet the need for precise knowledge of the snap joints' behaviour in the context of automotive development and crashworthiness. An experimental programme explores the intricacies of testing snap joints and reveals a high scatter of their strength, dimensional and tribological properties. The mechanical behaviour of exemplary joints is studied further via high-fidelity numerical models, expanding the experimental results towards arbitrary loading directions and dynamic characterisation. A sensitivity analysis quantitatively evaluates the significance of various factors. Finally, a common concept for the reduced modelling of joints by means of connectors is implemented and examined for the exemplary snap joint designs in the context of crashworthiness analysis.