Research on Design Method for Noise and Vibration Reduction in Ventral Plate Spacecraft Structure

To solve the problem that noise and vibration reduction of ventral plate spacecraft structure in orbit,a structure optimal design method based on FEM/IBEM for fluid-solid coupling system was proposed.The front 20 orders free modal of object was solved by Block-Lanczos,and then makes modal contribution analysis for overall structure under attitude control engine with indirect boundary element method,and finally ascertain panel which made the greatest acoustics contribution for position of sensitive instrument.This panel is object of optimal design,topology optimization and shape optimization are performed to maximize the lowest frequency,optimization results show that the maximum peak sound pressure of sensitive instrument droppes 21.27 dB and overall quality reduces 6.83 kg,it get the ideal effects of vibration and noise reduction.