Vibration Reduction Method And Experimental Research Of Constrained Damping Layer For Space Scientific Experimental Rack

With China’s manned space project entering the era of space station,the demand for scientific experiments on the space station is increasing.In the space science laboratory,the space science experiment rack is used as a module unit to support scientific experiments.With the launch of the carrier rocket,the space scientific experimental rack has to withstand complex external loads,resulting in excessive vibration response and structural damage.In addition,due to the strict restrictions on the structure design and weight in the aerospace field,it is very important to solve the problem of excessive vibration response under the premise of meeting the design requirements of space experimental rack.In order to solve this problem,this paper studies the application of viscoelastic constrained damping layer in vibration reduction of experimental rack.The structure of constrained damping layer is simple and has little effect on the structure size and weight,so it has a good application prospect.In this paper,firstly,the excessive vibration response position of the experimental rack is analyzed.Secondly,the damping mechanism of space science experiment cabinet is studied.A finite element model of viscoelastic constrained damping layer considering frequency-dependent characteristics is established according to the finite element method.Finally,an additional viscoelastic constrained damping layer is used to reduce the vibration response amplitude of the space scientific experimental rack.The main research contents are as follows(1)The vibration response position of space scientific experimental rack is analyzed,firstly,the finite element model of space scientific experimental rack is established,and the analysis of modal and vibration response is carried out.By comparing the simulation results with the test data of vibration response for the experimental rack,the accuracy of the finite element model of the experimental rack is verified,and the direction and position of the excessive vibration response of the experimental rack are determined.(2)The damping mechanism of space science experiment rack is studied,and the damping energy dissipation characteristics of the materials in the constrained damping layer are analyzed.Based on the mechanical model of viscoelastic damping material,the mechanical properties of viscoelastic damping material are described from multi-scale perspective,and the test data is fitted based on the least square method to construct the dynamic mechanical performance relationship expression of the viscoelastic damping material ZN-3.Through static and dynamic tests of viscoelastic damping materials,the accuracy of the established micro model and macro mechanical properties relationship expression is verified.(3)For the viscoelastic constrained damping layer,firstly,the finite element model of the viscoelastic constrained damping layer considering frequency-dependent characteristics is established.The modal loss factor is solved based on the modal strain energy method,and the iterative calculation is used to modify the solution results to obtain the fixed frequency and modal loss factor of the structure considering frequency-dependent characteristics.The accuracy of the modeling method is verified by comparing the theoretical values with the experimental results.(4)On the basis of the above research on damping mechanism of space science experiment cabinet and finite element modeling analysis of constrained damping layer,the constrained damping material is laid in the position where the vibration response of the experiment cabinet is too large.Through the finite element simulation analysis and experimental test,the vibration reduction effect of the constrained damping layer of the space science experiment cabinet in the frequency range of 0-100 Hz is verified.