Dynamic modeling and model order-reduction of on-orbit assembled multi-plate structures

On-orbit assembly is a pivotal enabling technology for advancing spacecraft modularity and autonomy. However, the accurate modeling and efficient simulation of on-orbit assembled structures face significant challenges, due to their evolving configurations, large degrees of freedom, and high interconnection complexity. This work proposes an efficient model order-reduction (MOR) method to enable fast and accurate simulation for space on-orbit assembled multi-plate structures. The dynamic model is developed using a reference nodal coordinate formulation, which captures the high-fidelity dynamics, albeit resulting in a high-dimensional system. A nonlinear modal reduction approach is further applied to generate a compact reduced-order model, incorporating global vibration modes and modal derivatives to preserve good accuracy. The key issue in MOR – optimal mode selection – is resolved through a novel kinetic-energy-based modal interaction method, which identifies dominant modes without prior full-order simulations, making it particularly suited for varying topologies. The proposed method is validated with octagonal and rectangular assemblies. Numerical results demonstrate that the method exhibits high accuracy, strong adaptability, and excellent efficiency. Notably, the computational cost is decreased for nearly 99%. The proposed method offers a promising technique for the dynamic analysis and control in space missions.