Research On Secondary Development Of Metal Rubber Finite Element Simulation

Metal rubber has good elasticity,damping characteristics,high and low temperature resistance,corrosion resistance and other excellent mechanical properties,has been widely used in aviation,navigation and other cutting-edge military fields.Existing finite element analysis software ANSYS and ABAQUS,we adopt equivalent to simulate metal rubber nonlinear material,not from the mesoscopic structure theory analysis of metal rubber,analysis the stress of the metal rubber deformation situation,so,in the simulation parameters meaning is not clear,the experimental data dependence is stronger,poor universality were the problem.In this paper,the annular metal rubber specimen is taken as the research object,and the metal rubber constitutive model of simply supported beam is proposed.On this basis,the finite element analysis software ABAQUS is used for the secondary development and customization of metal rubber material,which provides an important reference for the finite element analysis and application of metal rubber.The mechanical deformation of metal rubber was studied by analyzing the elastic action model of metal wire in metal rubber and the friction energy dissipation principle between wire and wire.Spiral coil and small pieces of curved beam are analyzed the quantitative relationship between the geometric characteristics and function,and the metal rubber nets piece of micro element,the spiral coil series parallel combination relations,analyzes the constitutive relation of metal rubber,beam metal rubber constitutive model is put forward,explained from the perspective of mesoscopic metal rubber loading compression,inside the interaction mechanism between the curved beam,It also explains the formation mechanism of nonlinear mechanical characteristics of metal rubber.Then,the model was verified by specimens with different relative densities,and the error was compared with the cantilever beam constitutive model and the porous constitutive model.The results showed that:Compared with cantilever beam model,porous model,beam metal rubber constitutive model with the experimental data fitting error is smaller,the better able to response the quasi-static compression mechanical performance of metal rubber,also can better reflect the wire,wire diameter,spiral coil diameter,relative density and other process parameters on the influence law of metal rubber nonlinear mechanics performance,It provides theoretical basis for finite element simulation analysis and engineering application of metal rubber.Aiming at the problems of metal rubber finite element simulation analysis,on the basis of the established metal rubber constitutive relation of simply supported beam,the metal rubber material was redeveloped and defined by UMAT,the user material subroutine provided by ABAQUS.Firstly,according to the quasi-static compression test results of metal rubber mesh,the proportionality coefficient of constitutive equation of metal rubber is solved by least square method.Secondly,the ramet constant of metal rubber material is calculated,the incremental constitutive equation is analyzed,and the consistent tangent modulus of metal rubber material is derived.Then,ABAQUS2016,INF2013 and VS2013 are inlined to build the running environment of user material subroutine UMAT,and use Fortran language to write user material custom program UMAT file in VS2013.Finally,metal rubber mesh blocks with relative densities of 0.20 and 0.30 are used for quasi-static compression simulation and experimental verification.The results show that:?The finite element simulation results are in good agreement with the experimental data,indicating that the secondary development of metal rubber finite element simulation has high accuracy and rationality,which can provide great reference value for the simulation of metal rubber.?The results can be used to determine the proportional coefficient of the constitutive equation with the small size metal rubber mesh block,to carry out the finite element simulation of the large size metal rubber mesh block,and can also be further used in the stress and strain simulation calculation,strength analysis and safety evaluation of the metal rubber shock absorber,reducing the design cost of the shock absorber.