延伸-分离一体化结构设计与分析

Design and Analysis of Extension-separation Integrated Structure

针对高动态、强冲击环境下延伸结构的展开、分离问题,采用过盈装配约束和摩擦做功耗能设计原理,设计降冲击延伸-分离一体化结构,实现级间结构能量缓释。采用Johnson-Cook动态本构模型,结合有限元方法,开展延伸-分离一体化结构动态冲击变形行为数值模拟研究,分析一体化结构在高动态载荷下的冲击响应;基于数值模拟结果,获得不同设计参数条件下延伸-分离结构支反力和加速度等时空演化规律,揭示小球半径、削弱段直径等参数对降冲击效果的影响机制,探究级间分离结构最优参数;基于高应变率拉伸试验机,设计高动态冲击下级间分离结构变形与失效的拉伸试验测试系统,对模拟结果进行试验验证。数值模拟结果表明,在保证削弱段不会提前断裂和延伸喷管可以正常展开的前提下,降低削弱段尺寸与过盈量,可有效提升降冲击效果,可以将强冲击载荷调控为需要的合适载荷。

In response to the deployment and separation issues of extended structures in high dynamic and strong impact environments,the principle of interference assembly constraints and friction as power consumption energy design is adopted to design an integrated structure of impact reduction extension separation,achieving energy release of interstage structures.Using the Johnson-Cook dynamic constitutive model and the finite element method,the numerical simulation study of the dynamic impact deformation behavior of the extension-separation integrated structure is carried out,and the impact response of the integrated structure under high dynamic load is analyzed.Based on the numerical simulation results,the spatiotemporal evolution laws such as the support reaction force and acceleration of the extension-separation structure under different design parameters are obtained,the influence mechanism of the radius of the globule and the diameter of the weakened segment on the impact reduction effect is revealed,and the optimal parameters of the interstage separation structure are explored.Based on the tensile testing machine with high strain rate,a tensile test system for separating structural deformation and failure between stages under high dynamic impact is designed,and the simulation results are verified by experiments.The numerical simulation results show that under the premise of ensuring that the weakening section will not break in advance and the extension nozzle can be deployed normally,the size and interference amount of the weakening section can be reduced,the impact reduction effect can be effectively improved,and the strong shock load can be adjusted to the appropriate load required.