Structural Optimization Of Rubber Elastic Components

Typical rubber component such as rubber bushing is taken as a research object inthis paper, and the structure optimization problem is discussed. Due to uniquehyperelasticity and viscoelasticity of rubber material, rubber bushing has been widelyused in the railway industry. It can transfer multi-directional loads in axial direction,radial direction, torsional direction and deflection direction, and can play a role ofeliminating impact and vibration during the load transfer process. A typical rubberbushing consists of a rubber body, a metal sleeve and a metal shaft. In structural design ofrubber bushing, in order to avoid excessively big tensile stress, grooves are arranged atthe external side of the rubber cylinder so as to improve the stress condition by freedeformation of rubber. Furthermore, grooves can be used for realizing the stiffness ratioin specific solid direction and empty direction. In this paper, the influences of thicknessand arc length of grooves on the stiffness are researched. Dimension optimization onrubber pad is also researched.Main research contents and results are summarized as follows:Research progress of rubber hyperelastic constitutive model is briefly introduced.Several hyperelastic constitutive models are analyzed with the data for mechanicalbehavior tests for standard samples of rubber materials used for rubber bushing, such asuniaxial test, biaxial test and planar test. Applicability of each model to the constitutivemodel of rubber material of the rubber bushing is discussed. It is indicated by the resultsthat Ogden model (N=3) can well describe the mechanical behavior under all threedeformation modes.Rubber bushing is optimized by ATOM optimization module of software ABAQUS.By calculation, volume of rubber material is reduced, simultaneously maximum Misesstress is effectively improved, and stiffness of rubber bushing is improved. Results showthat quality of new product can be effectively improved and costs can be reduced greatlywhen grooves are designed in rubber bushing.Dimension optimization programs are compiled on the grooves of rubber pad andrubber bushing by Python language of the software ABAQUS. Radius of external profilecan be controlled by calculating the horizontal displacement of the middle point ofexternal profile under a vertical load, so as to provide effective information for the designof rubber pad. As to the groove design of rubber bushing, this program can provide a relationship diagrams including the parameters such as radius, width, arc length of thegroove, as well as the ratio of stiffness in solid direction and in empty direction. Bymodifying the program, effective information can be provided to structural optimizationdesign of other rubber bushing structures, and object-oriented functions such asparameterized product modeling, analysis and output can be developed.