Optimization Of Multiple Frontal Impact Crashworthiness Of A Certain Vehicle

In the three major accidents of frontal impact,side impact and rear-end impact,both the incidence and the proportion of occupants who died of the frontal impact accidents rank first,and those frontal impact accidents have resulted in huge casualties and huge economic losses.The frontal impact accidents in reality are often complicated in form,and the structural crashworthiness of a single frontal impact cannot fully ensure the safety of occupants.Therefore,it is urgent to research the safety crashworthiness of the vehicle in various frontal impact conditions.In order to improve the impact safety crashworthiness of vehicles in complex frontal accidents effectively,this paper evaluates the crashworthiness of an vehicle in various frontal impact conditions combining the 2018 version of C-NCAP management rules and the China Insurance Automobile Safety Index(C-IASI),and a unified method of optimization designing for the crashworthiness of various frontal impact structures is explored based on the principle of energy management.The main research method of this paper is to research the reasons for the poor crashworthiness of a passenger vehicle in four frontal crash conditions,which are an 100% overlapping rigid barrier impact,a frontal 40% overlap deformable moving barrier impact,a frontal 25% offset impact and a front center rigid column impact.And based on the principle of energy management,this paper analyzes and proposes the optimization methods in structural crashworthiness of the target vehicle in four frontal impact conditions.In this paper,based on the full vehicle model issued by the National Crash Analysis Center,a finite element model of 100% overlapping rigid barrier impact and the other three finite element models of frontal impact conditions are established.The four types of impact structural crashworthiness are analyzed according to their different evaluation criteria.Prioritization schemes based on the energy management principle for the crashworthiness in various working conditions are proposed.Prioritization schemes of each working condition are applied to the corresponding finite element model for optimization effectiveness verification.The model integrating all prioritization schemes is verified for multiple working conditions and the reason why some indicator is not up to the standard of its condition is analyzed.This paper proposes a quadratic optimization and verification of the sectional structure that needs to be improved of the multi-case synthesized test model,and makes sure that the secondary optimal model meets the target requirements for the four frontal impact conditions.The results of the research show: based on the energy management principle,the energy absorption capacity of the front-end structures in the process of impact can be effectively improved by mainly optimizing the material and thickness,structure or the arrangement of different main energy-absorbing parts of the front-end structure in different working conditions,the shock on the passenger compartment is able to be fallen off,the structural crashworthiness of the vehicle in various frontal impact conditions is improved at the same time,and the safety of the occupant is further ensured.The effectiveness of each optimization method purposed is theoretically proved in this paper,and this paper is able to make references for improving the structural crashworthiness of vehicles in various frontal impact conditions.