Abstract: To reduce the weight of the vehicle body, a lightweight design was applied to the metal battery pack lid using glass fiber composite materials. The process involved utilizing black flame-retardant glass fiber grid cloth prepreg and DP590 steel plate integrated molding technology. Through experiments and microscopic analysis, acid-base cleaning, sandblasting, and electrophoretic coating were identified as the optimal modifications for the steel plate. Nine orthogonal experiments were designed for glass fiber-steel plate reinforced composite materials with a total thickness of 1.5 mm. Simulation analysis and experimental testing were conducted for the nine different combinations, focusing on bending and tensile simulations as well as testing experiments. The mechanical properties of the composite materials were obtained, with a maximum relative deviation of 1.49% between simulation and testing results, indicating the reliability of the simulation. Through extreme difference analysis of the orthogonal experiment results, the optimal process parameter combination was determined to achieve the best bonding strength. The recommended parameters include a mold temperature of 150 ℃, molding pressure of 12 MPa, steel plate thickness of 0.8 mm, and a 1+1 steel plate composite structure. The tested samples met design requirements for peel strength, water absorption, flame resistance, heat deformation temperature, and voltage resistance. The weight reduction achieved was 39.4%, meeting the requirements for lightweight design.

Key words: battery pack, glass fiber, steel plate, lightweight, composite materials