计入关节摩擦的空间桁架结构动力学建模及共振分析

The joint nonlinearity has an important influence on the overall dynamic characteristics of large deployable space truss structures. By modeling the joint as a combination of six spring elements which can have nonlinearity in any direction, the nonlinear dynamic modeling and resonance analysis of truss structures are studied. The bilinear hysteresis model is used to simulate the friction in the joint, and the analytical expressions of its equivalent stiffness and equivalent damping coefficients are derived based on the describing function method. The dynamic condensation of the truss member with nonlinear joints at both ends is carried out to establish the overall condensed dynamic model of the truss structure in the frequency domain, and the dynamic response is solved by the Newton-Raphson iteration method. A numerical example is given to compare the results of the presented method and the finite element method, which verifies the accuracy and efficiency of the presented method.