| The metal-rubber rollers structure is widely used in printing,textile,packaging,agricultural machinery and other fields.The metal-rubber rollers rotate in contact with each other to play the functions of media transfer between rollers,mechanical transmission,product material forming and transmission.The structural transmission smoothness is closely related to the contact characteristics of the rollers structure.In industrial applications,the steel-rubber roller structure is a typical combination of rollers.The contact characteristics of the steel-rubber roller structure directly affect the medium transfer or material forming process between the rollers.Due to the difference in rigidity of the steel and rubber,the contact deformation occurs on the surface of the rubber roller.Therefore,the mechanical behavior and contact characteristics of the rubber roller directly affect the structure operation and function realization.As a typical polymer material,in addition to typical characteristics such as large deformation and low modulus,the existence of creep,relaxation,and temperature-frequency sensitivity and other viscoelastic properties have multiple complex effects on the mechanical behavior of rubber-containing mechanical structures.The influence of rubber material characteristics on the contact characteristics of mechanical structures is of great significance and academic value.This article takes the steel-rubber roller structure during rolling and contact as the research object.By constructing the rubber constitutive model,modifying the structural contact theory,conducting experiments on the dynamic contact characteristics of the structure and simulating this problem under different constitutive models and working conditions,the influence of rubber viscoelastic properties on structural contact characteristics and the mechanism of rubber viscoelastic properties were studied.Firstly,the characteristics of rubber materials were studied.On the basis of the analysis and summary of the rubber hyperelastic constitutive model and viscoelastic constitutive model,the rubber dynamic thermal analysis experiment was carried out to determine the viscoelastic data of two nitrile rubber with the Shore hardness of 40 and 50.Based on the experimental data,a hyperelastic-viscoelastic composite constitutive model suitable for rubber materials in this paper was constructed to accurately define the materials.Secondly,the Hertzian contact theory of the classic cylinder is modified by multiple factors.The instantaneous steel-rubber roller contact theory which can comprehensively consider the characteristics of rubber materials,working conditions and temperature is obtained.For the practical application of industry,the engineering parameter Ve for judging the influence degree of rubber viscoelasticity is proposed,and the proposed modified contact theory and analysis method are numerically programmed.Then,in combination with the proposed modified contact theory,the contact characteristics of the steel-rubber roller structure are further studied through experimental verification and simulation.Through the comprehensive comparison of theoretical calculations,experimental data and simulations,the variation rules of structural contact characteristics under different rubber constitutive and rubber material parameters and different load-speed conditions are analyzed.Some specific contents were discussed,such as the applicability of the constitutive model,the effect of material hardness and temperature changes on the contact characteristics of the structure,and the influence of operating conditions on the weight,and the viscoelastic hysteresis of rubber.The influence relationship and mechanism of viscoelastic properties and the working conditions on the structural contact are studied. |
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