FE Micromodel of a Cord-rubber Composite Test Specimen Subjected to Uniaxial Tension

Abstract

The aim of this study is to examine displacements, strains and stresses as well as to predict possible failure mechanisms arising at the yarn-matrix level of a test specimen of a railway composite cord-rubber air brake tube undergoing uniaxial tension by microscale modelling.
Furthermore, this paper also aims to verify the material properties of the micromodel of the test specimen.
The micromodel is based on macromodels (by matching the boundary conditions of the micromodels with displacements of the macromodels) created previously by authors of this article. The reinforcing yarns are described by an orthotropic, elastic material model, whereas the matrix has been described by a 2 parameter Mooney-Rivlin model, which all have been validated before by a uniaxial tensile test and a three-point bending test.
Force-displacement curves of the micromodel and experimental results show a considerably good agreement.
Yarns have a less dominant role in the load transfer mechanism of the reinforcement layers, because of the short-yarn reinforced nature of the specimen. Shear strains are high at free yarn ends marking the possible locations of failure initiation in debonding in the shear mechanism of the reinforcement layers. High shear strain values imply that the dominant mode of load transfer is shear in the matrix in the reinforcement layers.