Irregular ANCF model and experimental investigations of the irregular membrane structures with variable cross-section

The membrane spacecraft structures are widely used for deep space exploration and on-orbit operation, but the dynamic responses of them is more complex. To advance the state of membrane structures, in this paper, a new ANCF membrane element is established to model dynamic equations of the membrane structure precisely and efficiently. Firstly, the irregular ANCF membrane element is studied by considering anomalistic boundary and variable cross-section. The mapping relations between the sub-ANCF element and the parent-ANCF element are illuminated by the Jacobian matrix, which makes the strain of each irregular element accurately calculated with the same shape functions. It is helpful to improve the description accuracy of inherent attributes and reduce the element number of dynamic systems. Further, the nonlinear dynamic model for membrane spacecraft system is established by the virtual work principle. Finally, the numerical examples and experiments are analyzed to verify the correctness of the proposed method and discuss the influence of nonlinear geometry and distortion on the dynamic behaviors. The results from the time domain and frequency domain analyses demonstrate that the distinct irregular geometric boundary of the irregular spacecraft can be more accurately modeled using the presented method. However, the difference becomes more pronounced when the distortion is too large. The research outcomes of this paper can provide theoretical guidance for the irregular spacecraft system, which is of great significance and urgently needs to be studied.