大型空间柔性桁架结构等效建模与动力学分析

Equivalent modeling and dynamic analysis for large flexible space truss structures

大型空间柔性桁架结构具有周期性、大柔度、构型复杂等特点,其等效建模是进行振动控制器设计的关键性技术之一。基于能量等效原理和经典Timoshenko梁理论,对刚性连接的大型空间柔性正三棱柱桁架结构进行了等效建模与动力学分析,采用Taylor展开方法推导了等效梁模型的刚度和质量表达式,对比分析桁架结构与等效梁模型的固有振动特性,二者吻合较好。数值结果表明了等效方法的有效性且等效梁模型具有较高的精度。

Large flexible space truss structures have features of periodicity,large flexibility and complex configuration,their equivalent modeling is one of key techniques to design vibration controllers.Here,based on the energy equivalent principle and the classical Timoshenko beam theory,equivalent modeling and dynamic analysis were conducted for a large space flexible positive triangular prism truss structure with rigid joints.Taylor expansion method was used to derive its equivalent beam model’s stiffness and mass expressions,and the natural vibration characteristics of the truss structure and its equivalent beam were analyzed contrastively.Both of them agreed better with each other.The numerical results showed that the proposed equivalent approach is effective;the equivalent beam model has a higher accuracy.