Study On Lightweight Of Micro Vehicle Body Based On Collision Safety

In contemporary society,car helps people enjoy a more convenient life, simultaneously bring such problems as automotive exhaust pollution, traffic safety and resource depletion.With the growing degradation of resources shortages and environmental contamination,the government has legislated relevant laws and regulations such a emission regulation, traffic safety code and energy consumption regulations, automobile consumption regulations also got increasingly improved. Under the pressure of fierce competition and legal restraint, major automobile manufacturers have intensified automotive research and development. The auto-body, as one of the most important parts of auto, played an important role on vehicle quality, safety feature, strength and comfort. It has become a critical technical problem of how to optimize dynamic and static characteristics of auto-body based on lighten body mass.This study put forward a method which could lighten auto-body structure based on sensitivity analysis and collision safety. Firstly, we took the thickness of micro-car body components as research object to optimize the auto-body characteristics under the constraints of body modal and stiffness, aiming to achieve the body quality minimization. Then, we compared the vehicle crashworthiness before and after lightweight in front impact condition, further to optimize the key energy absorption, at the same time,verified the validity of the optimization process.Specific research results obtained were listed as following:(1)The functional properties of each part of the micro-car body were analyzed, the affects on longeron crashworthiness were compared under different collisionmass, restrained beam and centroid position, finally we obtain the corresponding reasonable stringer structure. In addition, we got the optimum material for the body modeling.(2)The mold's accuracy and computational efficiency were ensured via simplifying micro-car body structure and processing the grid and spot. Stiffness characteristics and modal frequency parameter before the lightweight were studied, further we identified the research direction and the target value of relevant parameters.(3)The appropriate lightweight body structural member were screened out based on the sensitivity analysis, then we construct the mathematical model and obtained the optimal thickness of the body member by calculating.(4)Vehicle crashworthiness before and after lightweight in front impact condition were studied, with that we strengthened and optimized the key energy absorption from structural optimization and high-strength steel replacement. Finally, micro-car's B-pillar peak acceleration and firewall intrusion volume were both optimized, at the same time, verified the validity of the optimization process.