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We consider composites made of hydrogenated nitrile butadiene rubber (HNBR) and
particles of zirconium tungstate (ZrW2O8). We focus on finite element (FE) modelling of a
finite-strain mechanical behaviour of the composite and validation of the numerical simulation
against experiments. Based on examination of composite microstructure by scanning electron
microscope and optical analysis of particle images, realistic representative volume elements
(RVE) of microstructure are generated taking into consideration the particles circularity and
size distributions. Then FE simulations are performed to study the influence of the
microstructure and matrix-filler interface conditions on the mechanical properties of the
composites. It is assumed that the mechanical behaviour of rubber is non-linear, while the
tungstate particles are modelled by a linear elastic material. The FE simulations reproduce
uniaxial compression tests. Two types of interface condition between matrix and particles are
simulated: a perfect adhesion and absence of adhesion. Corresponding stress-strain curves are
constructed. Comparison with experiments shows that the real stress-strain curves for preloaded
samples path within intervals given by the modelling, i.e. pre-loading leads to partial
damage of bonding between matrix and particles.
Keywords: elastomer composite, representative volume element, effective stress-strain curve, damage, debonding. |
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