Lightweight Optimization Of A SUV's B Pillar Based On Side-impact

In recent years,the huge increase of car ownership has brought great pressure to energy supply,environmental protection and traffic safety.The research shows that reducing body weight can solve the above problems to a great extent.The lightweight of car means that reducing the weight of the car as much as possible when it meets the requirement of mechanical properties.Automobile lightweight and collision safety are contradictory.Hence,improving the safety of collision is an important problem in lighting the car.The lightweight design of B pillar is based on the side impact in this paper.The side of the car is a weak area of the body.In the side impact,there are small energy-absorbing space,less energy-absorbing components and high risk of injury for occupant.As a significant structure in side,B pillar not only bear huge impact force,but also support other component like car door and door bar.What's more,the intrusion of B columns and the speed of invasion directly affect the safety of the occupant.So it is meaningful to study the crashworthiness of B pillar in improving the safety of side impact.Firstly,this paper established a finite element model of a domestic SUV based on GB20071 side impact law.Next,the change of energy,lateral deformation,intrusion of B pillar and invasion velocity of B pillar were analyzed.According to the evaluation criteria of side impact of C-NCAP,this work takes the invasion and velocity of B pillar as constraints to ensure the enough crashworthiness of car.Then the outer plate of B pillar was constructed by TRB rather than traditional uniform thickness plate.Adopting TRB can reduce the mass of the outer plate of B pillar dramatically.In this paper,the outer plate of B pillar was divided into five regions.In order to the best thickness and position of five regions,deterministic optimization was carried out,which was based on the experimental design and the approximate model of RBF neural network.Finally,the 6? robustness optimization design was accomplished by the results of deterministic optimization.In contract with original design,the mass of optimized design was reduced by 10.9%;the intrusion of optimized result was reduce by8.84%;the intrusion velocity is reduced by 15.4%.Furthermore,it was high robustness and reliability of the optimized design.