ABSTRACT To improve the performance of the body‐in‐white (BIW) and achieve automotive lightweighting, a balanced approach across materials, techniques, and structures is required to save costs. This study describes an optimization approach for a partitioned carbon fiber composite floor based on composite material failure criteria, which employs a hybrid Particle Swarm Optimization (PSO) and Bacterial Foraging Optimization (BFO). A finite element model for the BIW was created and verified using simulation and experimental data. The steel middle floor was separated from the BIW model based on its stiffness, and static bending and torsion simulations were used to get stiffness information. The T700/WP‐R2300 composite material's characteristics were determined by quasi‐static mechanical testing. The middle floor was optimized using free‐size optimization, dimension optimization, and a ply stacking sequence design. The performance of the optimized carbon fiber composite floor was compared to a traditional steel floor. The results showed that the carbon fiber composite floor's bending stiffness rose by 74%, torsional stiffness by 46%, and weight was reduced by 46.7%. When combined with the BIW, the carbon fiber composite floor increased bending stiffness by 4.6%, torsional stiffness by 8.3%, and the initial bending and torsional frequencies by 8.8% and 7.4%, respectively, exhibiting considerable lightweighting effects.
Zhu et al. (2026) studied this question.