RESEARCH ON STRUCTURAL PERFORMANCE AND LIGHTWEIGHTING OF PLASTIC TAILGATES FOR NEW ENERGY VEHICLES

To reduce energy consumption in new energy vehicles (NEVs), the substitution of steel with plastic for tailgates has emerged.The main challenges of plastic tailgates lie in controlling mechanical performance, dimensional tolerances, and weight.The plastic tailgate studied in this paper features an inner panel made of PP+LGF40 and an outer panel made of PP+EPDM-TD30, with metal reinforcements added on both sides of the inner panel.A simulation analysis was conducted to replicate the real-world assembly conditions of the plastic tailgate, comparing the effects of different metal reinforcement processes on its mechanical performance.Under the premise of meeting performance targets, topology and size optimization were applied to maximize lightweighting.Finally, test validation was performed to verify the simulation model.The results show that: Using insert molding for the metal reinforcements in the inner panel improves mechanical performance by 9.2% compared to bolted connections while reducing manufacturing steps.Simulating real-world assembly conditions and applying pre-deformation to the inner panel ensures that the tailgate meets gap and flushness requirements after vehicle assembly.Optimization achieves a maximum weight reduction of 1.6 kg for the tailgate assembly.Test validation confirms that the simulation model has a 95% confidence level.