充气展开自支撑臂振动模态分析

充气展开自支撑臂是由层合铝膜和离散自支撑壳组成，可在无充气压力下实现对有效载荷的支撑。为提高充气展开自支撑臂振动特性预测精度，首先，基于Timoshenko梁理论和哈密顿原理，推导了自支撑臂振动微分方程，提出了考虑充气压力的预应力和构型变化的梁单元模型。该单元模型考虑了结构自支撑壳的离散分布特性，使建立的质量矩阵更接近自支撑臂结构的真实值。然后，通过实验对该模型进行验证，结果表明本文方法比传统梁单元模型具有更好的精度。最后，分析了充气压力和自支撑壳宽度等参数对自支撑臂结构振动模态的影响规律，结果可为充气展开自支撑臂的设计提供理论参考。

Vibration modal analysis of inflatable self-supporting booms

The inflatable self-supporting boom,which is made of laminated aluminum film and local discrete self-supporting thin shell,has the ability to support the effective load at zero inner pressure.In order to improve the accuracy predicting the vibration characteristics of the inflatable self-supporting boom,the vibration differential equation of the self-supporting boom was first deduced based on the Timoshenko beam theory and Hamiltonian principle,and a new beam element model considering the prestress and configuration change for inflation pressure was proposed.Moreover,this beam element model also considers the discrete characteristics of the self-supporting shell in self-supporting boom,and the mass matrix established by this model is closer to true value.Then,this beam element model is verified by the vibration test results,and the verified results show that this model has better accuracy than the traditional beam element model.Finally,the influence of the inflatable pressure and the width of self-supporting shell on the vibration characteristics of the self-supporting booms is analyzed.This study would provide a theoretical reference for the design of the inflatable self-supporting boom.