A model updating method for solar array considering the influence of gravity

Abstract

The geometric nonlinearity caused by gravity can not be neglected when conducting ground modal test of solar array on the ground. So a new model updating method for flexible structures considering the influence of gravity is proposed in this paper. First, the stress stiffness matrix in ground environment is derived, then the modes are calculated by solving the generalized eigenvalue problem. After matching tested mode shapes with calculated ones, the sensitivity analysis of the parameters is carried out. Then the proper parameters are chosen and updated by using a iteration process. A numerical simulation of a deployed and locked solar array is conducted, it is found that gravity has influence on the modal frequency. The elastic parameters of the single panel and the connection stiffness of the hinges between different solar array panels are updated step by step. The study shows that proposed method is fast and accurate.