Abstract: An engineering simplified approach to the general formulation for the dynamics of flexible spacecraft is presented on the basis of the complete second-order differential equations. First, the integral items are simplified based on the translational lumped mass method, and the element inertia and rotational motions for shell element or beam element are omitted. Thus, the complex volume integral computation is transformed to the summation operation of variables multiplied by translational masses. Second, the nonlinear matrix coefficients are simplified to constant matrix based on “the small deformation assumption”, while omitting the impact of the elastic displacements on the position vectors. Therefore, all the items of the general formulation for the dynamics of flexible spacecraft are well preserved, but their computation is remarkably simplified. The approach could be used for the analysis of flexible spacecraft with largeamplitude and complex motions, and further extended from single-body to multi-body in order to solve the dynamics of on-orbit construction structures or space robots/arms. Finally, the approach is verified by multiple numerical examples and an application case.

Key words: flexible spacecraft, dynamics, general formulation, engineering simplified approach, translational lumped mass method