Study On Crashworthiness Of Car Front Bumper System

Front bumper system is the system located at the front of the body to ease the impact,being played a protective role to varying degrees in the vehicle speed offset collision,low speed and lower extremity pedestrian collisions.low-speed collision and pedestrian protection performance is gradually added vehicle safety performance development process at home and abroad.In our country the 2018 version of the C-NCAP,pedestrian protection is brought into legislation procedures.Therefore,considering the design the former security system to meet the high-speed offset crash performance,low-speed crash performance,pedestrian protection performance,it is of great significance to improve vehicle safety.Firstly,according to C-NCAP,RCAR,E-NCAP,the researchers were established a domestic high-speed car crash finite element model,low-offset crash finite element model and the Flex-GTR flexible lower limbs crash finite element model.Analyzing the front of the vehicle security system crashworthiness in accordance with evaluation criteria of relevant laws and regulations,the results showed that the three conditions of the system structure cannot meet the requirements of crashworthiness.Secondly,making the main structural parameters of front bumper system as variables process DOE orthogonal experiment design,then using range method to analysis of the primary and secondary structure variable factors and the influence of the impact of each performance,the researchers integrated consider three conditions performance,and re-optimize and match the structure of the former security system.Experimental results show that high-speed and low-speed collision offset crash and lower extremity pedestrian collision performance are improvedFinally,based on orthogonal optimization,the researchers make a lightweight design for the former security system.using multi-objective genetic algorithms as means and the horizontal thickness of the components of front bumper system as variables,in the case of the former security system to ensure the crashworthiness to optimize their quality.The optimized bumper system by finite element simulation experiments verified in high-speed offset collision force enhanced,the back invade amount of low-speed collisions and pedestrian lower extremity injuries in collisions are within a predetermined range,improves crashworthiness.Overall lower quality of the former security system reduces to meat the requirement.