大型柔性整流罩分离特点仿真分析

Simulations and analyses on separation characteristics of large scale flexible fairing

建立整流罩刚体及弹性体有限元模型,联合大型商用软件MSC.Nastran及LS-DYNA对新一代大型运载火箭整流罩分离过程进行仿真分析。通过与刚体模型对比,分析分离过程中整流罩自由模态、变形特点、运动轨迹、能量变化及呼吸运动对分离角速度、罩内可用包络空间的影响。结果表明,整流罩呼吸运动对罩内可用包络空间影响最大区域为后柱段下端,对整流罩质心运动轨迹影响较小,能明显减小过顶角速度及脱钩角速度,使过顶、脱钩时间有所延迟,致分离弹簧势能损失约36%。结论可为整流罩分离系统优化设计、提高整流罩分离可靠性等提供重要参考。

The rigid and flexible finite element models of a large scale flexible fairing were established. Then the separation of fairing in a new generation launch vehicle was simulated by using combinedly the softwares MSC.Nastran and LS-DYNA.Comparing with the results by the rigid model,the elastic deformation of fairing,its motion trail as well as its energy consumption in the process of separation were analyzed.Besides,the effect of elastic vibration on the separation angular velocity and available envelope space were discussed.The results demonstrate that the available envelope space influenced most significantly by elastic vibration is at the end region of the colum and the elastic vibration has little influence on the displacements of fairing centroid.It also shows that the separation angular velocity will decrease due to elastic vibration when the fairing centroid is passing through the top or the fairing is being unhooked from the launch vehicle and at that time,36 percent elastic potential energy of the spring is wasted.These conclusions can provide important reference to the structural optimization of fairing separation system and the improvement of reliability of the separation process.