Numerical modelling of hybrid-bonded joints

To manufacture multi-material hybrid parts for the automotive industry, mechanical joiningprocesses like riveting are well established. However, adhesive bonding is increasingly beingused in the car body. The combination of the specific advantages of both joining techniques inform of hybrid joints yields in synergies of manufacturing, crash and durability performance.Critical issues are the formation of adhesive bags in the region of the mechanical junctionsand global deformations of the metal blanks between the mechanical joints. Bags in the regionof the mechanical junctions decrease the strength of the mechanical joints [1]. Globaldeformations caused by the formation of adhesives bags while the multi-point mechanicalfixation process takes place, influence the smoothness of the bonded part’s surface [2]. Thisproject focuses the numerical simulation of the time dependent formation process of bothtypes of bags.The subject of the work presented is focussed on self-pierce-riveting in combination withadhesive bonding. In the industrial process chain the rivets are set before the adhesive iscured. A FEA reference model is developed for the elementary riveting processes. The modelmust be expanded with the displacement of the liquid adhesive. Coupled fluid-structuresimulations, which include the interaction of the solid matter influenced in the mechanicaljoining process and the fluid adhesive, are presented. In a last step a surrogate model for themulti-point hybrid joint is developed. Simulations are compared with the results ofexperiments carried out in [1], [2].Based on the increased process knowledge due to simulation the hybrid joining processes canbe optimized for industrial use by improved selection of materials and process parameters