工装约束下火箭舱段壳体的结构振动特性研究

Research on Solid Rocket Cabin Shell Structural Vibration Characteristics with Frock Boundary Constraints

将地面试验中卡环工装对舱段壳的影响转化为弹性边界条件下圆柱壳耦合结构的振动问题,通过卡环工装与圆柱壳接触建模计算得到工装作用于舱段壳的法向约束刚度,并采用增补函数的方法构建了工装约束边界条件下圆柱壳耦合结构的振动理论分析模型。结果表明:本研究模型能够反映卡环工装对于舱段壳振动特性的影响,理论计算结果与试验测试结果的变化趋势基本一致;在卡环工装的约束下,舱段壳的低频振动受到显著抑制,工装的约束刚度及其在舱段壳上的夹持位置对于舱段壳振动特性具有较大影响。

Rocket cabin shells are usually constrained by clasp frocks in ground tests,which will have a signifi⁃cant influence on structural vibration characteristics.A model of coupled cylindrical shells with elastic bound⁃ary constraints is established in this paper.The normal constraint stiffness was obtained by the contact calcula⁃tion model between clasp frocks and cabin shells,and the supplementary functions are used for expressing the bending vibration displacement of the cylindrical shells.Results showed that measured data follow the same trends as the theory model prediction;the low-frequency vibration response of cabin shells is deeply sup⁃pressed by frock boundary constraints,indicating great influences from both constraint stiffness and relative position.