A Study On The Structural Improvements Of Vehicle Rear Impact In Low-speed

Occupancy’s injuries caused by low-speed compared with high-speed is not so great and could not cause too much attention. However, the low-speed impact destruction of the vehicle is smaller, so the vehicles can achieve the reuse through repairing or replacing the related components, it’s bound to affect the interests of consumers and insurance companies, insurance companies will be in accordance with the low-speed car crash test results to evaluate the grade of car insurance, all these factors influence consumers’ purchase intention. Therefore, it is very significant to improve the vehicle’s safety performance and reduce the maintenance costs.In order to research vehicle low-speed crashworthiness, this paper based on some vehicle model built up a vehicle-trolley finite element simulation model of rear impact in low-speed, according to the RCAR regulatory requirements. Rear carling effective plastic deformation value act as the evaluation index, Each parameter of vehicle’s rear bumper system was analyzed to have an affect on the deformation of the rear carling, Orthogonal test was designed to select the sampling points, and the co-integrated balance was used to optimize the match of the thickness and material of the vehicle rear bumper beam, thin-walled tube thickness and the thickness of the rear carling, and energy absorbing foam was added to improve the structure of the tail between the rear vehicle skin and rear bumper beam; Under Chinese low-speed rear collision regulations the rear carling deformation, the bumper system deformation and the invasive amount of impactor before and after improvement was went along Comparative analysis.The results show that:the thickness of the beam and rear carling had a greatest affect on effective plastic deformation in the low-speed impact; The optimal matching of the material and thickness of the beam, the thickness of the thin-walled tube and thickness of rear carling could make the rear carling effective plastic strain values decreased by about69.8%, then through adding rigid polyurethane foam to tail the rear carling effective plastic strain value can be decreased by about81.2%, rear carling deformation can be controlled below5%by these ways, the performance of impact in low-speed was improved and maintenance costs was saved; Under Chinese collision regulations, the deformation of beams and thin-walled tube had a little increased and deformation of rear carling has decreased by about72.5%in longitudinal collision and the beam does not produce any deformation in the angle of collision, improving its low-speed collision performance after improvement; the analysis shows that the vehicle was accorded with Chinese low-speed regulations well, but far from being able to meet the requirements of the RCAR regulations. The paper proves the effectiveness of improvement theoretically, provides a reference to improve the rear impact security in low-speed collision research and provides a litter theoretical basis and support for our country to join in the RCAR organization.