Abstract: Aiming at the difficult modeling problem of dynamic analysis model caused by complex composition of spacecraft equipment, a method of finite element model simplification based on topology optimization was proposed.In this method, the measured mass characteristics of the spacecraft equipment were taken as the constraint condition, and the material distribution in the feasible design space of the finite element model of the equipment was determined by the topology optimization method.Then the stiffness performance of the structure was simulated, and finally the simplified finite element model of the equipment was obtained to meet the needs of dynamic characteristics analysis.A simplified finite element model of a star sensor was established by using this method.This obtained model is basically consistent with the actual mass, centroid position and moment of inertia of the product, and the maximum frequency deviation of the first two orders between the analysis values and the experimental values is less than 30%.Then, the simplified model was applied to the dynamic response performance evaluation of the support structure.The analysis data of natural frequency and acceleration response trend of the assembly are in line with the test data under the frequency range below 450Hz, and the maximum deviation of natural frequency is about 39%.The application results verify the rationality of the simplified finite element modeling method based on topology optimization technology, which provides a new solution for simplified finite element modeling of complex spacecraft equipment dynamics analysis.

Key words: spacecraft equipment, model simplification, topology optimization, finite element, dynamic characteristics