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

Abstract

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. Copyright © 2004 Society of Chemical Industry

Optimisation of vehicle engine mount system using simulation-based design approach

“…Material constants in the strain energy density functions are generally determined from curve fitting of experimental stress-strain data. There are several different types of experiments, but in general, a combination of simple tension, simple compression, and pure shear tests are used to determine the material constants (Kim et al, 2004). A major difficulty in the use of finite element codes is the experimental determination of the material constants to use in the model chosen for simulation (Bradley et al, 2001).…”

“…During the compression of the sample, the strains appeared at lateral directions are not restricted entirely. It is quite difficult to achieve an effective compression test due to the friction between the specimen and the compression platens (Kim et al, 2004). If friction exists, then the stress and strain distributions are not uniform.…”

“…Kim and Kim (1997) introduced the shape optimisation of engine mount with desired stiffness curve using Mooney-Rivlin material model. Kim et al (2004) studied on the experimental test methods for determination of the rubber material properties necessary for non-linear finite element analysis (FEA). It is shown that the predictions of FEA are close to the experimental results .…”

Hyper‐viscoelastic characterization of highly filled rubber compound: Extending approach for geometrical defect analysis

“…[ 11–14, 16, 17 ] Unfilled and filled rubber compounds are mostly characterized by hyperelastic constitutive models for mechanical behavior during instantaneous loading. [ 18 ] Hyperelastic behavior is derived through the change in entropy of the cross‐linked and entangled network in terms of strain energy density as a function of strain invariants. Numerous well accepted hyperelastic constitutive models developed based on the entropy change are Mooney–Rivlin, Neo–Hookean, Arruda–Boyce, Ogden, Yeoh, etc.…”

Comparison of Test Specimens for Characterizing the Dynamic Properties of Rubber

“…These include: cylindrical double shear [4][5][6], bi-conical shear [7], rectangular double shear [8][9][10] cylindrical compression [11][12][13][14] tension hourglass [15], compression-tension hourglass [6,16], cylindrical compression-tension [17,18], ASTM tension [13,19], strip tension [14,18,20] plane strain compression [12], and double shear beam. In selecting a specimen, several factors should be considered in addition to homogeneity of mechanical fields within the specimen.…”