民机机身结构适坠性数值研究
The Crashworthiness Analysis of the Civil Aircraft Fuselage Structure Based on the Finite Element Method

以某型民机机身舱段结构为研究对象,建立了机身舱段结构有限元模型,通过LS-Dyna软件进行了机身结构坠撞过程模拟,得到了不同条件下机身结构坠撞响应,研究了机身结构适坠性与其局部结构布局、坠撞边界条件及吸能材料应用间的关系,分析了机身变形、客舱地板加速度变化等适坠性关键因素。结果表明:机身结构变形随着初始撞击速度的增加而增大,变形部位由机舱底部扩展至舱内地板结构;通过采取支撑结构、在客舱地板下填充泡沫材料等抗坠毁吸能设计,延缓客舱地板加速度峰值出现的时间,可降低客舱地板加速度峰值,有效提高机身结构适坠性。
In order to analyze the crashworthiness of civil aircraft structure, a numerical fuselage structure model based on the Finite Element method(FEM) was built to study the structural deformation under different impact velocities. The results demonstrated that, with the increasing of initial impact velocities, the deformation of the fuselage nonlinearly increased, and the deformation position extended from the bottom of the fuselage to the cabin floor, which may threat the safety of passengers. Moreover, the optimization of the local structural design and application of energy absorbing material would decrease the acceleration peak value transmitted to passengers, but they have different mechanism of action. In general, as one of the effective approach, the numerical method can improve the structural crashworthiness in aircraft design stage which may reduce the cost and risk of the airworthiness certification test