DIRECT-COUPLED LOAD VERIFICATION OF MODIFIED STRUCTURAL COMPONENT

An analytical verification method for structural dynamics subject to p artial design change is proposed, The method can predict time-domain s tructural dynamic responses after the changes are implemented, incorpo rated with the entire structural characteristics including the unchang ed portion, by using small numbers of modal parameters of the original structure and the modified component, The concise computation of the degrees of freedom of the modal representation, which are formulated t o retain the residual flexibility in the equation of motion, can corre ctly provide changed effects. The representation of the component mode synthesis and the force equilibrium between the changed component and the main structure are utilized to develop the algorithm, which yield s the modal mass-stiffness conversion in the component modes, Applying this method to the spacecraft redesign, without the physical property information of the launch vehicle or repetition of coupled load analy sis, the established algorithm can improve the prediction of the coupl ed spacecraft and launch vehicle structural dynamics. A reanalysis can be implemented using a limited number of available modal parameters f rom the coupled analysis for the original structure, Demonstrations ap plied to simple beam and spacecraft-launch vehicle models presented sh ow the effectiveness of the method.