Research On Vehicle Safety Performance And Collision Compatibility Analysis And Optimization For Moderate Overlap Crash

Frontal collision accident is the most important form of road traffic collision accident in China,and the moderate overlap collision mode poses a greater threat to occupant safety and requires higher vehicle safety performance.Therefore,based on the situation,it is necessary to consider not only the design of a reasonable front-end structure plan,the improvement of the overall crashworthiness of the passenger compartment and the matching of reasonable occupant restraint system parameters to enhance the passive safety performance of the vehicle,but also eliminate collision between vehicles in collision avoidance design,geometry size and stiffness differences.Differences in anti-collision design,geometric dimensions and structural rigidity.It is necessary to comprehensively consider improving the ability of the car to protect the safety of its occupants and reduce the damage of the opposing vehicle during a collision,that is,collision compatibility.Based on the above considerations,this dissertation carried out the following research in the aspects of the dynamic influence law of medium overlap collision form on the crashworthiness of car body structure,the impact mechanism of collision damage on occupants and the impact mechanism of vehicle collision compatibility:First,on the basis of a certain automobile finite element model,a moderate overlap collision finite element model was built and its effectiveness was verified.Lay the model foundation for the follow-up work.Secondly,the deformation state of the vehicle body structure and the dynamic injury response of the dummy on the driver’s side are analyzed and compared in detail to explore the dynamic influence of the moderate overlap collision mode on the crashworthiness of the vehicle body structure and the collision injury mechanism to the occupants.Then,based on the current evaluation procedures.The vehicle collision compatibility is comprehensively discussed and applied from four aspects,including the geometry and uniformity of the front-end structure of the target vehicle;the dynamic impact response of the target vehicle to the occupants of the attacked vehicle;the intrusion depth and height of the barriers of medium and large target vehicles with strong aggressiveness.And for the current compatibility evaluation criterion,the intuitive quantification of the degree of intrusion of the target vehicle to the target vehicle lacks continuity and universality.A new compatibility evaluation criterion—energy absorption rate r_E is proposed,and its effectiveness and rationality are verified.Finally,with the goal of improving the collision compatibility of the vehicle,the relevant design variables are selected for optimal solution based on the method of automatic update of the parameterized model.Form a set of parameter-driven multi-objective optimization design schemes that integrate design of experimental method,metamodel technology and global optimization algorithm.The research results show that the new compatibility evaluation criterion proposed in this dissertation-energy absorption rate r_E,can achieve continuous quantitative evaluation of the aggressiveness of the target vehicle.It solves the lack of intuitive and continuous quantification of aggressiveness in the current compatibility evaluation system.The parameterized optimization strategy can improve the optimization efficiency while ensuring the accuracy of the model.The optimization results show that the standard deviation of barrier deformation is reduced by 20.6%,the occupant load criterion is reduced by 9.7%,and the energy absorption rate r_E is reduced by 7.6%.This dissertation has certain reference value for the subsequent research on safety performance and collision compatibility of moderate overlap collisions.