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.