A RESEARCH ON SHOCK PREDICTION METHOD CORRELATED WITH FORMOSAT-2 SATELLITE PYRO-SHOCK TEST RESULTS

摘要

At the beginning of a satellite development program, the system engineers have to define the prospectivecomponent environmental specifications based on the selected launch environments for the successive fightcomponent designs or procurements. A stricter specification normally means more budgets for the program. Thus,how to reasonably define the component environmental specifications is a critical task for system engineers.Shock or pyro-shock is one of the important specifications for shock sensitive components. In a launch vehicleuser's guide, the shock environment is normally expressed by shock response spectrum (SRS). The SRS generallyhas high g (gravity) value in the range of high frequencies. Theoretically, the level of shocks will be attenuated bystructure elements, such as panels, beams, fasteners, etc., when shock waves propagate on a structure. There is nosimple and easy way to predict shock propagation on a satellite structure. This paper proposes an analysis methodthat transfers the SRS at the shock source that is usually provided in a launch vehicle user's guide, to time historythen using LS-DYNA as the analysis tool to predict the shock at the positions where are interested on the satellitestructure. To validate the method, the whole processes are applied on the FORMOSAT-2 satellite (which is the 2ndsatellite of NSPO, National SPace Organization of Taiwan, ROC, launched in 2004) and the predicted SRS curvesare compared with FORMOSAT-2 satellite pyro-shock test data.This method is not a rigorous mathematical analysis, but an engineering approach to provide system engineersimmediate and more accountable information for the component shock environment definition.When the whole process is accomplished, several "representative SRS curves" are created. Those curvesrepresent the shock responses on the selected regions of a structure, which can be directly used in the definition ofthe component shock specification.