Prediction of elastic modulus of polymer composites using Hashin-Shtrikman bound, mean field homogenization and finite element technique

Polymer matrix composites are developed by reinforcing biodegradable rubber seed shell, cashew nut shell and walnut shell powder in epoxy resin. Theoretically, elastic modulus is calculated using Hashin-Shtrikman bounds using variational principles. Investigation of the elastic modulus of the composites is extended by varying filler weight up to 25% in Digimat 2017-MF which applies Mori-Tanaka mean field homogenization and ANSYS 15.0 Workbench which uses a three-dimensional model of representative volume element having spherical shaped filler particles to calculate elastic modulus. Elastic modulus is the measurement of resistance of the material under tensile load. The corresponding stress-strain relationship predicts the stiffness of the material. The results are confirmed with experimentation approach for 5% wt filler content. Elastic modulus obtained from these approaches show a maximum error of 7% with experiment results. Investigation further reveals that elastic modulus of composites increases with increase in weight fraction of fillers. However, above 15% wt of filler content, no significant increase in the elastic modulus of the composites is observed.