带油箱结构的机身框段坠撞仿真分析

 主要研究了任意拉格朗日/欧拉耦合方法计算带油箱的机身框段的坠撞过程。首先，建立了带油箱结构的机身框段坠撞分析模型，包括机身框段结构模型和欧拉流体模型。采用水代替油箱内部燃油，考虑了不同装水量对机身框段耐撞性的影响。分析了坠撞过程中的液体晃动和泼溅与机身坠撞响应的影响，给出了装水量和机身框段最大垂向压缩位移、最大过载和能量吸收等参数之间的关系。通过仿真分析，揭示了冲击载荷作用下油箱内部燃油量对机身框段各个部分结构的损伤破坏的影响。研究指出，在垂直撞击环境下，机身加强框和蒙皮是主要的吸能结构。在油箱内装水量多的情况下，油箱结构的吸能作用不能忽略。给出了应急着陆或可生存坠撞事故发生前，飞行员所应采取的紧急措施。

Crash Simulation of Fuselage Section with Fuel Tank

A numerical model for the crash simulation of a fuselage section with a fuel tank is developed in this paper.The fluid-structure interaction is considered in the impact simulation using the arbitrary Lagrangian/Eulerian coupling method.The whole model consists of a finite element model of the fuselage section with a fuel tank and an Eulerian model of the water inside the fuel tank,which is used instead of fuel.Crashworthiness of the fuselage section under the influence of the water volume inside the fuel tank is taken into account.How the water sloshing inside the fuel tank influences the deformation of the fuselage section is analyzed.The relationship is established between the water volume and the maximal vertical impact displacement,overload and energy absorption of the fuselage section.Simulation results reveal the relationship between the fuel weight and the responses and failure of the fuselage section.Numerical results show that most of the impact energy is absorbed by the stiffening frame and out-skin,and that the energy absorbed by the fuel tank cannot be ignored when there is a lot of water in it.Recommendations are made to the pilots to deal with emergency landing or survive crash conditions.