Vibration Analysis of Periodic Trusses with Rigid Joints Using an Energy Equivalent Method

Purpose: Dynamic modeling of large-scale periodic trusses is critical for the structure optimization and vibration control of the truss. Due to the large size and complex modeling, the equivalent model of periodic trusses has been of concern to researchers. Methods: This article suggested an equivalent model of a periodic truss with concentrated mass and rigid joints using finite element and energy equivalent techniques. The kinetic energy and strain energy of the truss were first calculated using the finite element method, and then the energy equivalent model of the periodic truss was developed. This section also included a detailed description of the solution method. Second, the effectiveness of the model and the influence of the concentrated mass and the bending deformation of the truss members on the accuracy of the equivalent model have been carried out successively. Results: The results demonstrate that the vibration and static characteristics of the equivalent model are in good agreement with the full-scale periodic truss. Meanwhile, this study also indicates that the bending deformation of the truss member has little effect on the low-order mode. By contrast, the concentrated mass, such as truss joints, has a greater impact on dynamic characteristics. Conclusions: As a result, the equivalent model reveals the relationship between the physical parameters of the periodic truss and its dynamic characteristics, which has guiding significance for the dynamic analysis and control law design of large-scale flexible space trusses.