MODAL ANALYSIS OF THE DYNAMIC MODEL OF A MOCKUP, A SMALL SPACECRAFT
The article describes method of experimental determination of dynamic behavior of rocket and space equipment, using the example, a small spacecraft. Experimentally obtained modal characteristics (natural modes and frequencies) are compared with modal characteristics calculated for the said spacecraft using the finite element model (FEM). The natural modes and characters of the spacecraft were experimentally obtained using scanning laser vibrometry; the modal analysis was performed using finite elements and the MSC.Patran/Nastran FEM package. Objectives and tasks have been formulated; main stages of the modal analysis have been described. FEMs of spacecraft parts must be improved to obtain precise loads applied to such parts. Dynamic characteristics of spacecraft structural elements obtained during the research will allow creating more precise and reliable spacecraft dynamic models at the design stage; this, in its turn, will improve precision of load calculations and reliability of the spacecraft in general.