Simulation And Optimization Design Of Structural Crashworthiness For Minibus Frontal Crash

There is a wide market in china for minibus due to its economical efficiency,mobility and smartness. However, it commonly has poor crashworthiness performancebecause of the short energy absorption length. In the process of crashworthinessdesign, the kinetic energy of the vehicle should be absorbed by the front structure,simultaneously, the body deformation should be efficiently controlled to leave livingspace for passengers. Therefore, Developing a effective structural crashworthinessoptimization design method is of significance for the improvement of crashworthinessand the increase of product quality.The vehicle collision is a dynamic process with large displacements anddeformations, which could not be expressed explicitly. Confronted with optimumdesign of crashworthiness, surrogate model technology is commonly used. If thewhole vehicle model is adopted for sampling, the calculation resource consuming willbe very large. However, when a simplified model rather than the whole vehicle wasapplied, the computation efficiency will be raised with the reduced computationalrequirement.This paper studies the crashworthiness optimization design for a new developedminibus. Firstly the100%frontal impact simulation is conducted. Bas ed on the issuesexisted in the initial structural design, corresponding improvement schemes arebrought out. The design schemes of lengthening the energy absorption structure,reducing the intrusion and increasing the structure stiffness are proposed, by whichthe crashworthiness performance has been significantly improved and the minibus hassmoothly passed the national frontal impact regulation GB11551-2003. In order toimprove the crashworthiness as much as possible and to meet the requirement oflightweight design, further researches on the optimal design for principal energyabsorption structures are carried out, in which the simplified model rather than thewhole vehicle model is used to raise the computation efficiency with the computationtime reduced. In the process of design, the optimal Latin hypercube designs, Kringapproximation model and NSGA-II genetic algorithm are adopted to optimize thestructure parameters, which are critical to the structural crashworthiness. Good resultsare acquired with the improvement of the vehicle crashworthiness and the reductionof the total weight of the critical energy absorption member.As the research indicates, the method presented in this paper is feasible to improve the structural crashworthiness of the minibus quickly, economically, andefficiently, which makes important sense to cut the production costs, to shorten thedevelopment cycle and to increase the product quality.