飞机撞击特大型LNG储罐全过程仿真分析

采用数值模拟方法对飞机撞击特大型LNG储罐的全过程进行仿真分析。分析中采用LS-DYNA有限元程序，考虑罐体、储液与保温层间的相互问题，建立了F-15战斗机的SPH模型，对飞机材料的选择和参数确定进行了详细分析，并以Riera法为依据，对F-15战斗机SPH模型撞击刚体所产生的荷载进行了对比验证，对比结果证明了SPH模型的可靠性和实用性。分析结果表明：撞击角度越大，外罐所承受的撞击能量越大，相应的内罐破坏越小，因此垂直撞击为最不利撞击角度；撞击高度对整体工况计算结果影响不大，储罐在经受215m/s撞击速度撞击下均出现了严重破坏；112m/s撞击速度时内罐尚有安全余量，160m/s撞击速度时内罐撞击中心区域内材料已达到极限应变，因此可认为目前设计方法设计的储罐所能承受的最大撞击速度为160m/s。

Whole process simulation analysis of aircraft crash into extra-large LNG storage

Whole process of aircraft crash into extra-large LNG storage tank has been simulated using numerical method. The LS-DYNA program has been used to build the SPH model of F-15 aircraft considering the interaction of tank, LNG, insulating and layer. The material model and parameter has been chosen and analyzed for aircraft. Based on Riera method, the comparison between numerical load and analytical load has been made to prove the reliability and practicability of SPH model. The analysis result reveal that, the impact energy which absorbed by outer tank increases with the increase of impact angle, so vertical impact is the worst angle. The height of aircraft impact position doesn’t affect the response of tank. When the impact speed of aircraft is 215m/s, the tank will be destroyed seriously. If the speed reduces to 160m/s, the stress of inner tank material approach to maximum value, so 160m/s can be deemed to the maximum impact speed using the existing design method.