Analysis on effect of injection residual stress on impact resistance of composite wheel made of long glass fiber reinforced thermoplastic

The application of composite materials is an important measure to reduce the automotive wheel’s weight. In order to ensure the safety of passengers, the wheels must pass a series of tests including the 13° impact test. For an injection-molded wheel, its production process has an influence on the material properties and residual stress distribution, which affect the wheel’s mechanical performance. In this paper, the residual stress is introduced to analyze its effect on the impact resistance of composite wheels made of long glass fiber reinforced thermoplastic. First, to obtain the material properties, the specimens are subjected to the tensile test. Based on the test data, the properties including failure parameters can be obtained by reverse engineering. Next, the in-cavity residual stress can be obtained by mold flow simulation, after simulating the relaxation of residual stress during demolding process, the residual stress is introduced to the 13° impact test model. Last, the simulation and corresponding tests with different impact velocities are carried out. The results illustrate that the fracture of the wheel can be accurately simulated by using the simulation method, and the residual stress generated by injection molding process has little effect on the response or damage of the wheel. Considering the calculation efficiency, it is unnecessary to introduce the residual stress when simulating the performance of composite wheel under 13° impact load. This method can also provide an effective reference for subsequent design and simulation for composite wheels.