Abstract: To enhance the lightweight quality and crash safety of automobile B-pillar assembly, this paper puts forth a hybrid material B-pillar assembly design scheme comprising a high-strength steel outer plate, a carbon fiber composite inner plate, and a glued connection between the two. A finite element analysis model must be established for a dynamic impact drop hammer collision test of an automobile B-pillar. The validity of the model must then be verified from the hourglass energy test. A finite element model of a carbon fiber composite B-pillar reinforcing plate must be established, along with the layup design of the carbon fiber composite B-pillar reinforcing plate. Finally, the optimal carbon fiber composite layup sequence must be obtained. The carbon fiber composite B-pillar reinforcement plate was affixed to the high-strength steel outer plate via an adhesive bonding process to construct the B-pillar assembly specimen of the hybrid material. The accuracy and validity of the simulation model were further verified by dynamic drop weight tests and impact failure electron microscopy tests. The results demonstrated that the carbon fiber composite material B-pillar reinforcement panel reduced weight by 0.623 kg, and the hybrid material B-pillar assembly reduced the maximum displacement during the collision process by 12.8% in the falling weight impact test. The discrepancy between the simulation optimization and the actual test results did not exceed 5%. This substantiates the accuracy and reliability of this solution, and the lightweight effect and collision safety were markedly enhanced.

Key words: hybrid material B-pillar assembly, crash resistance, carbon fiber reinforced plastic, lightweight design method, electron microscope damage test