Research On Fe Model And Optimization Analysis Of Laminated Windshield Based On Pedestrian Head Protection

In person-car accident, the pedestrian head collision with the windshield is one of the most important causes of pedestrian casualties. How to improve the pedestrian head safety has become a hot issue of vehicle passive safety research. This paper had carried on the comprehensive analysis and studied to provide reference for the pedestrian protection research through numerical simulation, experimental research and optimization design, reduced pedestrian head injuries in car accident, and achieved the purpose of protecting pedestrians.In the study of headform impact windshield simulation model, the extended finite element method theory was analyzed and its differences with the traditional finite element method was studied. The energy release rate of â…  type crack was deduced. The realization of extended finite element method in ABAQUS was studied, the validity of the extended finite element simulation of crack propagation was verified by a simple numerical example. The windshield geometry model obtained by reverse engineering, the windshield glass grid model was obtained by HYPERMESH, the grid model was imported into ABAQUS to complete the simulation model, and several kinds of methods to solve the problem of extended finite element convergence were discussed.In the research of building the test bench of adult headform impact on the windshield, according to the national standard of "The protection of motor vehicle for pedestrians in the event of a collision" in the relevant provisions, the design of adult headform impactor was completed. The laminated windshield safety, sound insulation performance were analyzed. According to the national standard, the test site was selected and the structure of the test was designed. Three axis acceleration data acquisition module was designed based on LABVIEW, and the data acquisition equipment was selected. Through the tests, the windshield crack propagation map and acceleration time history curve were obtained, and the accuracy of the simulation model was verified.The windshield was optimized based on the index of head injury. The pedestrian head injury index was studied, HIC value was chosen as the objective of optimization design, the windshield was optimized by changing the material and thickness of each layer. Optimal Latin hypercube design method and Krigin g approximation model were used, to optimize the parameters of windshield glass material, the HIC value decreased by 12.2%. On the basis of material selection, the windshield thickness of each layer was optimized. A design method was used to get the points in the design space. Neural network approximation model, chebyshev orthogonal polynomial approximation model and kriging approximation model were established for the design space, and approximate models were compared with the accuracy analysis. Multi-Island Genetic Algorithm and Adaptive Simulated Annealing were used to optimize approximate models, the two optimization results were compared. With no significant change in the total thickness of the windshield, the HIC value decreased by 26.38%, improved the protection performance of the windshield on the pedestrian head.