Nonlinear Finite Element Analysis And Failure Mechanism Study Of Rubber-steel Bimaterial

Rubber to metal bonded component are used widely in the engineering industry for applications such as suspension and mounting systems. Nonlinear mechanical properties of rubber in terms of both material and geometric behavior also make it difficult to get simple and rigorous solutions to product design problems. There are a limited number of closed–form analytical equations suitable for application in the design of elastomeric components. However, all appear to deal with components of the most simple geometric shapes and to be based on the assumptions including linear elastic behavior and incompressibility of the rubber. Fortunately, the advent and rapid development of the digital computer and computer based finite element analysis programs handling elastomeric material have provided a powerful means to further the study, understanding, and optimization of rubber in engineering applications. In this paper a thorough mechanical analysis of rubber-steel biomaterial was performed using nonlinear finite element approach. This dissertation mainly contains the following aspects:Describe the experiments of defining rubber material model in this paper. According to the true stress and strain curves the limitations of the material model are discussed. Make a conclusion about how to get stress and strain test data for the purpose of fitting material models in finite element analysis. Perform a nonlinear finite element analysis of torsion of a rubber cylinder which has a theoretical analytical solution. This allows an evaluation of the accuracy of the FEA technique in dealing with rubber material. The results show that with suitable selection of element types, solution algorithms and material models the FEA results consistent with the theoretical solution are obtained.Nonlinear finite element methods are employed to analyze the model of rubber bonded to steel sphere. Values of stiffness are calculated for various thicknesses of the rubber layer with different Poisson's ratio. They are in good agreement with earlier theoretical solution at small strain. Calculate the hydrostatic pressure distribution in the spherical interface and predict the location of initial failure of the model of rubber bonded to steel sphere.The effects of neglecting deviation from pure shear in the end regions are evaluated using non-linear finite element analysis. Calculations of tearing energy are made for a rubber pure shear specimen with a central crack or a edge crack in the specimen or at the rubber-to-steel bond. The tearing energy is independent of crack...