Design Of Anti-vibration Structure Based On Biological Structure Inspiration

Vibration exists everywhere in our daily life.Sometimes uncontrolled vibration will leadto serious consequences.In the space structure,uncontrollable vibration will cause irreversible damage to the precision electronic and mechanical equipment,and even lead to the failure of spacecraft launch.So the study of vibration mode control and energy absorption has been paid much attention.The disc spring can bear a large load in a small space and is widely used in the vibration mode control of spacecraft.But the stiffness of the traditional disc spring depends strongly on the applied load and gives an unstable natural frequency.In the past design of energy absorption and vibration reduction structure,the energy absorption and the structure life usually cannot be considered together.For example,porous materials can achieve high energy absorption with large deformation,but cannot be repeatedly used.To solve the above two problems,in this paper,the shape of disc spring is first optimized to obtain a stable stiffness in the full load range,i.e.,the natural frequency is independent of the load.Inspired by the energy and vibration absorption mechanism of the woodpecker's skull,a new viscoelastic energy absorption structure,named silicon rubber-disc spring composite structure,is designed and manufactured.The structure consists of silicon rubber,disc-springs and steel plates.The steel plates support the overall structure,the disc-springs bears the load and restore elastic deformation,and the silicon rubber provides viscoelastic viscous damping.So the structure can absorb energy repeatedly and reduce vibration.In this dissertation,by means of finite element simulation and experiment,the mechanical properties of disc spring,silicone rubber and the composite structure are investigated respectively,and the energy absorption efficiency of the structure is discussed.The main contents of this paper are as follows:(1)Through the comparison between the numerical analysis and the compression experiment of disc spring,it can be seen that the relationship between load and displacement of the traditional disc spring is nonlinear.In order to solve this problem,a method of shape optimization is proposed,which optimizes the top surface from a plane to a curve surface.The maximum stress of the optimized spring is reduced below the yield limit to avoid local yield and extend the service life of the disc spring.(2)Based on the uniaxial tensile,compression and relaxation experiments on the siliconerubber,the mechanical parameters are obtained by fitting the experimental curves.The experiments show that silicone rubber has good hyperelastic and viscoelastic mechanical properties.So the silicone rubber is suitable for a viscoelastic element of an energy-absorbing structure.(3)The compression process of single disc spring-silicon rubber composite structure is simulated.The results can predict the bearing capacity of the composite structure.Cyclic loading and unloading experiments are carried out on the single-layer composite structure with different number of disk springs.The energy absorption of composite structure is found not sensitive to the loading waveform.With the increase of the number of disc springs,the energy absorption is better.(4)The 4-layer disc spring-silicon rubber composite structure is designed and manufactured with large bearing capacity and high energy absorption efficiency.The maximum energy absorption efficiency can reach 60% and can be reused.