Study On The Applicability Of The High Elasticity Constitutive Equation Of Rubber Materials

There are many high elasticity constitutive equations of rubber materials in finite element software,but due to the characteristics of high elasticity,viscoelasticity and complex nonlinearity of rubber materials,so far there is still no clear research on its applicability for simulation calculations.Taking into account the current problems,this paper first discusses the calculation ability of the existing high elasticity constitutive equation in the software,and then discusses the influence of the modeling method on the calculation ability of the constitutive equation from the perspective of permanent deformation of the rubber material.The calculation ability of the constitutive equation is discussed from the perspective of the change of the Poisson's ratio of the rubber material.The purpose is to perfect the theoretical and applied research on the constitutive equations of rubber materials,and select the highly elastic constitutive equations with high calculation accuracy for engineering practice.The following is a research summary of my paper:1.Three basic tensile recovery tests were performed on natural rubber and solution polymerized styrene butadiene rubber,and basic experimental data to eliminate the Mullins effect were obtained,which were used to obtain the parameters of the highly elastic constitutive equation.At the same time,the reasons for the Mullins phenomenon and the effects of carbon black content,tensile rate,temperature,and strain on permanent deformation change law were discussed;2.The three basic experimental data of natural rubber and solution polymerized styrene butadiene rubber were divided into seven combinations,and the fitting results of different constitutive equations and the predictive ability of other basic experiments were explored,it plays a certain reference role in choosing the appropriate constitutive equation;The natural rubber cylindrical specimens were prepared and the geometric models of the cylindrical specimens were established.The natural rubber/SBR three-point bending specimens were prepared and the three-point bending specimen geometric models were established.The differences in the seven combinations were discussed.The calculation results of the constitutive equations,and successfully screened out the constitutive equations suitable for the finite element calculation of rubber materials in different combinations.The finite element calculations were carried out on the natural rubber with or without permanent deformation and the threepoint bending thick sample of the solution polymerized styrene butadiene rubber,and the calculation results of different constitutive equations were discussed;The calculation results of three-point bending specimens of solution polymerized styrene butadiene rubber under different strain conditions based on different constitutive equations based on three basic experimental data are studied.It is found that as the input basic experimental strain range decreases,the calculation results of the constitutive equation gradually Increase,it is more reasonable to choose 100%strain;3.The UHYPER high elastic material subroutine was briefly introduced,and the UHYPER subroutine for changing Poisson's ratio was successfully compiled and applied to the finite element calculation of rubber products.The geometric model of the O-ring seal was established,and the Mooney-Rivlin and Yeoh hyperelastic constitutive equations were selected to calculate the influence of the change of Poisson's ratio on the contact pressure.