Reliability Optimization Design Of The Minibus On Collision Performance

In recent years,China’s economy has developed rapidly and steadily,and cars have been an important way for people going out.Vehicle can bring convenience to our lives,meanwhile,there are also a series of social security issues caused by vehicle.The traffic accidents have already become a very serious problem of public safety and the frontal impact accounts for a considerable proportion.Currently,the research and development of the vehicle market on the collision performance is mainly concentrated in passenger cars,the proportion of the minibus is very few.In order to make up for this deficiency,this paper has optimized the collision performance of a mini bus based on C-NCAP.First,the relevant literature research and analysis of vehicle crash safety design has been read,and built the 100%frontal crash model of the minibus;8 thickness of the components which have obvious effect on vehicle crash performance were selected as design variables,and choose the appropriate evaluation index as the responses.Use DOE experimental design method to get 70 set training data and built Kriging approximate model based on the training data.The approximate model is optimized by PSO algorithm,in the optimized scheme,the a_maxax and m has decreased by 7.6%and0.87%,D1,D2 and D3 has decreased by 7.7%,3.1%and 5.3%,as we can see,the optimized scheme has a lot of space to improve.Then this paper seeks a better optimized scheme by improving the algorithm,and then the concept of chaos was introduced to improve the particle swarm optimization algorithm,the new algorithm has a better optimization performance.Use the chaotic PSO algorithm to optimize the approximate model,and compared two optimized schemes,the result shows that the optimized schemes based on new algorithm can improve the collision in a large way,in which a_maxax and m has decreased by 15.1%and0.9%,D1,D2 and D3 has decreased by 13.2%,7.3%and 9.8%.Therefore,it is regarded as the final deterministic optimized scheme.And then take the optimized variables to the original finite model to verify the optimization results.At last,this paper use 6σreliability optimization design method to get the uncertainty optimization design schemes,and analysis the optimize design result.The paper studies show that,due to the fact that deterministic optimization only considers the optimization index nut ignore the influence of noise factors,which leads it has a low reliability,which the realiability of a_max is only 0.49.Consider the noise factors,use 6σreliability optimization design method to was used as the optimization algorithm,then get the uncertainty optimization scheme.Compared to the deterministic optimization,the uncertainty optimization didn’t have a obvious improvement of the collision performance but it has a high reliability which makes it meet the requirements of practical engineering better.In the last,verified the 6σreliability optimization result,it shows that the fitting error is also within the acceptable range.This paper offers two types of optimization design for mini bus 100%frontal collision include deterministic optimization design and 6σreliability optimization design.The result shows that the 6σreliability optimization design can not only improve the mini bus collision performance but also can maintain a high reliability which can easily achieve in practical engineering,it is also helpful for the development of the minibus BIW design.At the same time,the improvement of particle swarm optimization can further enhancethe optimization effect,which provides a new idea for optimization design of automobile collision.