Crashworthiness Optimization of a Civil Airplane Sub-floor Structure

摘要

By means of controlling the deformation mode and reducing the contact stiffness,a sub-floor energy absorption structure of a civil airplane is designed.To improve the energy absorption features of the structure,the finite element model of the structure is built and ten design variables are choosen,based on the orthogonal experimental design;four typical structural impact responses of sample points are obtained by numerical analysis.According to an F-test,the design variables with high significance level are selected as the optimizing ones.An optimized sub-floor structure is obtained by using the response surface model.The analysis results show that,compared to the reference structure,the first peak value of the structural rigid acceleration of the optimized sub-floor structure reduces by 23.13%,the second peak value reduces by 49.86%,the average value reduces by 43.71%,the energy absorption time increases by 78.32%,the efficiency of energy absorption increases significantly,as more materials join in the energy absorption process.