Features of defining the damping function in spacecraft finite-element models

Dynamic analysis of spacecraft structures is a key item in the process of structure design. For example, a launch vehicle generates the highest loads, including dynamic ones, for most spacecraft structures. Determining of damping parameters is an important component in the analysis of the structure response to mechanical loads. It is therefore very important to be aware of the damping properties of the structure. The characterization of damping is important in making accurate predictions of the frequency response of any loaded structure. The article presents some excerpts from sources devoted to the space technique design, and containing information about damping in structures. The aim of the work was to improve the accuracy of calculations using finite element models. The paper demonstrates the results of the search for a method (form) of setting the damping function in the Femap software that would provide the correct levels of the frequency response of the structure to the loads applied. A finite element model of a cantilever beam was an object of the computational experiment carried out. A frequency table obtained at the modal analysis stage prove to be useful for frequency response analysis. The only one natural frequency in spectrum is enough to implement current study. Further, damping function was set in several ways in order to identify the one that provided the most correct response for the natural frequency under study.