Layout Optimization Design Of Damping Material For Satellite Instrument Panel

The satellite instrument panel will probably generate violent vibrations because of the random excitation during launching or in the orbit stage,which can affect the operation of instrument on structure lightly or damage the panel seriously.So it is important to research on the vibration control of the instrument panel.Due to the strict limitation of satellite mass,it is necessary to optimize the configuration of damping materials/structures to achieve structure lightweight.Aiming at improving the modal damping ratio of the instrument plate,this paper studies the layout optimization of constrained layer damping structure,embedded damping and filled damping structures with damping material mass constraint.Firstly,aiming at the layout optimization of constrained damping material on the panel surface,the update iteration format of the topology optimization algorithm is improved on the basis of model verification and influence parameter analysis,which solves the non-negative sensitivity problem of topology optimization and improves the numerical stability and the convergence effect in the solution process.Then,the layout of two typical instrument panels with constrained damping material is optimized.Secondly,aiming at the layout optimization of the embedded damping material in the honeycomb cell of the instrument panel,the equivalent material parameters of the sandwich panel with embedded damping are derived based on the cell equivalence theory,and the validity of equivalent derivation is verified by comparing the results with the 3D finite element model.The shape function of node interpolation method is used to optimize the layout of two typical instrument panels with embedded damping material,which transforms the topology optimization problem to the parameter optimization problem.Thirdly,aiming at the layout optimization of the filled damping material in the honeycomb core of the instrument panel,the 3D finite element model of filled damping instrument panel is established,and the influence of the parameters of filled damping structure on the dynamic characteristics is analyzed.Based on the improved topology optimization method with variable density,the layout optimization of filled damping material in two typical instrument panel is optimized.Finally,synthesized the above three kinds of damping layout optimization method and respectively taking the typical and actual satellite instrument panel as object,the layout optimization of constrained damping structure with variable thickness,the constrained damping and filled damping composite structure,the constrained damping and embedded damping composite structure are carried out.These results show that the damping material preferentially arranged in the area with the larger shear strain will improve the modal damping ratio of the instrument panel.Compared with embedded and filled damping structures,constrained damping structure is the most effective to reduce vibration of the satellite,and the thickness ratio optimization of the constrained damping layer has a significant influence on the structural modal damping ratio.For a certain satellite panel,by increasing the 2.1kg damping material,the modal damping ratio of the actual instrument panel is increased from 0.6% to 1.6%.