Research On Modeling And Experiment Of Metal-net-rubber Combination Shock Absorberhysteresis Mechanical Properties

The metal-net rubber material is a porous composite material composed entirely of metal wire woven,compared with the traditional spiral coiling metal-rubber material,process improvement,removing the interference of large amount of manual processes in the preparation process,improve the degree of mechanization,higher degree of coincidence,and have more stable mechanical properties.Because of its excellent bearing capacity,large damping,high temperature resistance,low temperature resistance,aging resistance,oil and corrosion resistance,it is stronger than traditional rubber,and is widely used in aerospace,shipbuilding,military weapons and other military industries.The mechanical properties of the metal-net rubber material screen showed the properties of hyperelasticity as rubber,viscoelastic properties but different from natural rubber material,the damping mechanism on the performance is dry friction damping,the consumption of energy afterthe sliding friction between wire produced by deformation under load.Therefore,on the basis of this,the metal-net rubber damper of a symmetrical structure design,according to the structure characteristics of this kind of shock absorber,established the energy dissipation model of metal-net rubber material,and verifying the accuracy of the model by experiment,finite element simulation gives the theoretical model of the real application,the specific content of this paper are as follows:1.The symmetric structure of composite metal-net rubber damper design,based on this structure,the stiffnessand hysteresis theory model combination damper parameters using the thought of parameter separation,the shock absorber subjected to cyclic loading when the restoring force displacement hysteresis curve for the superposition curve and dry friction damping force of the elastic restoring force curve this definition,two key parameters of damper: equivalent stiffness and friction damping coefficient.A theoretical model of equivalent stiffness is established,and a quantitative relationship between equivalent stiffness and molding parameters is deduced.In this paper,the stiffness nonlinearity caused by volume change is ignored,and the equivalent stiffness nonlinearity caused by initial relative density is only considered.According to the forming characteristics of metal-net rubber specimens,a nonlinear dry friction damping model is established,and the dry friction damping coefficient is defined to describe the energy dissipation characteristics of the shock absorber.2.Through the combination of static hysteresis damper and damper test,study the initial relative density,damper preload,loading amplitude and spring stiffness influence on the mechanical properties of the combined static hysteresis damper,decomposition test of restoring force displacement curve,calculating the equivalent stiffness of the test group and the unit volume energy dissipation and the energy dissipation coefficient,comparative analysis of changes of evaluation parameters with the above factors.The relative parameters of the theoretical model of the metal-netrubber stiffness hysteresis are obtained,and the test parameters and hysteresis curves are compared,and the error is analyzed.3.The influence of initial relative density,loading amplitude and loading frequency on the dynamic stiffness,rated load natural frequency and damping ratio of the metal-net rubber shock absorber is studied by means of the dynamic constant frequency test.4.Combined with the metal-net rubberstiffnessand hysteresis theory model,simulation and calculation of parameters of metal-net rubber material,the orthotropic elastic material model is chosen,mechanical properties of the hysteresis metal-net rubber damper is simulated by finite element simulation using ANSYS Workbench finite element simulation software,and the simulation of the shock absorber of restoring force displacement curve and test curve are compared,the results show that the smaller the results of simulation and experiment error,used simulation method can well describe the combination of metal-net rubber damper hysteresis,and this method can be used to simulate the hysteretic characteristics of the shock absorber for other test conditions.5.Proposed in the validation of the finite element simulation model of reliable premise,modal analysis and random vibration simulation of composite metal-net rubber damper using ANSYS Workbench finite element simulation software,the effects of specimen relative density,combination of shock absorber spring stiffness on the natural frequency,damping efficiency,RMS acceleration and impact response the regularity of PSD curve,the effects of vibration magnitude on the damping efficiency,random vibration input / response RMS acceleration and response curve of PSD.