Influence of filler content and interphase properties on large deformation micromechanics of particle filled acrylics

Large deformation response of alumina trihydrate (ATH) filled poly(methyl metacrylate) PMMA over a wide temperature range was investigated. A multi-particle unit cell model of PMMA/ATH composite with different volume fractions was employed to study the influence of interphase properties and interparticle distance. The model constitutes of amorphous polymer matrix, rigid fillers and interphase between filler and matrix. Polymer matrix was modeled using a thermodynamically consistent dual-mechanism viscoplastic model, whereas fillers were assumed as linear elastic. In numerical simulations, the interphase between filler and matrix was modeled through a user defined interphase model and matrix material was modeled through a user defined material model. Damage evolution in PMMA/ATH at large deformations due to particle debonding was studied based on a critical stress criterion. Composite elastic modulus results from finite element analysis of unit cell model were compared with analytical model predictions (Mori-Tanaka, Eshelby, Lielens models) at different temperatures for various volume fractions of fillers. The influence of interphase characteristics, interparticle distance and temperature on large deformation response of PMMA/ATH was examined through multi-particle unit cell model. (C) 2012 Elsevier Ltd. All rights reserved.