An investigation on crashworthiness performance of adhesive bonding in automobile hybrid front bumper system subjected to high-speed impact

Adhesive bonding is widely used to join dissimilar materials and has proven its effectiveness so far. This study investigates the crashworthiness performances of the adhesive bonding in automobile hybrid front bumper system which connects the composite bumper beam and steel crash boxes by carrying out a series of numerical analyses. Initially, the ply thickness and orientation of the composite bumper beam were optimized to achieve impact properties as good as the steel bumper beam. Later, performances of three adhesives, namely, Araldite® AV138, 3M® DP8005, and Nagase Chemtex® XNR6852E-3 with stiff, ductile, and high toughness, respectively were evaluated for the proposed configuration of the hybrid front bumper system and the proper adhesive was selected correspondingly. Finally, optimization studies were performed for the top and the side adhesives in terms of the impact characteristics of the adhesives. The results of this study showed that it was possible to use the adhesive bonding to join dissimilar materials in the automobile hybrid front bumper system with the proper adhesive. Moreover, the crashworthiness performance of the hybrid front bumper system was highly affected from the design configurations of the adhesives. It was found that the optimum hybrid front bumper system (Case 1) exhibited peak crush force of 656 kN and absorbed 4.07 kJ energy. In addition, the top and side adhesives absorbed 0.073 and 0.13 kJ of energy, respectively, while 16.12% and 22.48% of the elements used in the top and side adhesives failed. © 2022 Elsevier Ltd