客舱地板斜撑杆对民机典型机身段耐撞性能的影响

针对一类具有客舱地板下部斜撑杆的民机典型机身段,研究了斜撑杆对机身段耐撞性能的影响。建立了客舱地板及其下部结构的有限元模型,客舱地板以上的框段结构、乘员质量和座椅被简化为刚性质量块。分析了斜撑杆为开孔/不开孔开剖面结构、斜撑杆剖面尺寸变化以及无斜撑杆和刚性斜撑杆情况下,机身段在坠撞速度为7m/s时的冲击特性。对比分析了各种情况下座椅位置处的加速度-时间历程曲线、机身段的破坏模式和能量吸收情况。结果表明存在合适刚度的斜撑杆,使该类型机身结构具有良好的耐撞毁性能,而增加或减少斜撑杆刚度均有可能产生多次高过载。

Effect of Cabin-floor Oblique Strut on Crashworthiness of Typical Civil Aircraft Fuselage Section

This article investigates the effect of oblique struts on the crashworthiness of fuselage sections for a class of typical civil aircraft fuselage sections with oblique struts under the cabin floor.A finite element model of the cabin floor and its underneath structure is developed.Rigid blocks are used to simulate the structure above the cabin floor and the mass of the passenger and the seat.The impact characteristics of fuselage sections subjected tO 7 m/s vertical velocity are analyzed.Several typical conditions of oblique struts are considered,i.e.strut of different cross-sections with and without holes,rigid struts and no struts.A contrastive analysis is given of acceleration histories,failure mode and energy absorption of different fuselage sections.The result shows that there is a certain stiffness of the strut for the fuselage section that will exhibit good performance on crashworthiness.But more than two high accelerations may appear if the stiffness of the strut is increased or decreased.