Some considerations on mechanical testing methods of rubbery materials using nonlinear finite element analysis

This paper discusses experimental test methods for the purpose of defining the nonlinear properties of rubbery materials used for finite element analysis. The typical tests are simple tension, simple compression and pure shear tests. It has been found in the simple tension test that a narrow strip specimen whose length is 10 times longer than the width can be used more appropriately than a dumbbell type specimen. In order to eliminate the effect of friction between the specimen and the platens in the compression test, a tapered platen is suggested. The effect of the tapered platens is verified by experimental and finite element analysis. In a shear test, it has been shown that the specimen width must be at least 10 times larger than the height of the specimen. The mechanical preconditioning has significant effects on the prediction of the behaviours of rubbery materials and components. The static stiffness of an automotive engine mount is calculated by nonlinear finite element analysis using the experimentally determined material properties and is compared with experimental results that take into account the mechanical preconditioning effect, resulting in a good correlation. (C) 2004 Society of Chemical Industry.