Parametric Study for Dynamics of Spacecraft with Local Nonlinearities

摘要

Various kinds of connectors existing in most spacecraft are usually nonlinear and could strongly affect the dynamic characteristics of the spacecraft. For dynamic analysis, the spacecraft are generally idealized as finite-element models that often have huge numbers of degrees of freedom, while their connectors are spatially localized. In addition to forced harmonic response, the influences of the connectors' nonlinear parameters and/or the excitation levels on the response are also significant among major design considerations. However, it is computationally expensive to repetitively perform the analysis and computation for studying the effect of modifying nonlinear parameters and/or changing excitation levels with a direct method, especially for large-scale structures. Accordingly, an approach based on the pseudoarclength continuation scheme, the describing function, and linear receptance data is developed in the present paper. With linear receptance data, the computational efficiency of the pseudoarclength continuation scheme can be significantly enhanced and only associated with nonlinear degrees of freedom that usually constitute a small part of large-scale structures with local nonlinearities. A finite-element model of a satellite with nonlinear connectors is used to study the relationship among the response of the satellite's payloads, the excitation level, and the connectors' physical parameters.