地板下结构参数对民机适坠性的影响及优化

为了确保乘员在可生存事故中存活,民机结构必须具备适坠特性.适坠性设计的关键部位为客舱地板以下结构,包括底框、行李舱底部结构和行李舱支柱三个元素.对民机典型机身结构进行了简化,利用LS-DYNA3D建立了1/4缩比动力学仿真模型,考察了行李舱支柱位置、角度及行李舱高度变化对机身坠撞特性的影响.以改善机身适坠性能为目标对地板以下结构参数进行了综合优化,优化过程采用基于均匀试验设计的Kriging近似模型,大大降低了动力学优化的计算代价.优化结果表明合理选择行李舱支柱位置、角度及行李舱高度参数可以有效改善民机机身结构的适坠性能.

Simulation Research on Influence of Civil Aircraft Sub.floor Structural Parameters to Fuselage Crashworthiness and Optimization Based on Crashworthiness

For ensuring occupant'S survivability in case of survivable crash accidents.civil aircraft should have good crashworthiness.The key part of civil aircraft fuselage crashworthiness design iS sub-floor stmctures including sub-floor frames,structures under luggage cabin and luggage cabin struts.A typical civil aircraft fuselage was simplified and a 1/4-Scale dvnamics simulation model based on the simplified structure was built with LS-DYNA3D.a nonlinear dynamics analysis code.With the scale simulation model,the influence ofthe strut location.strut slope nngte and the luggage cabin height to drop and crash properties ofaircraft was investigated.For better crashworthiness,the civi,aircraft fuselage sub floor structural parameters were optimized based on Kriging model built from samples determined according to Uniform'Experimental Design(UED).which could decrease computation cost greatly.The results show that appropriate values ofthese structural parameters can improve the crashworthiness ofcivil aircraft fuselage structures effectively.