Micromechanical Modeling of Glass Filled Epoxy Using the Variational Asymptotic Method for Unit Cell Homogenization

Essentially, composite materials are formed by combining two or more constituents with different properties to obtain a new material with unique combination of features, thus has potential to provide value-added properties absent in one of the constituents. In this paper, the effects of glass particle size on mechanical properties of epoxy composite materials, such as stress, strain, and Young's modulus and its relationship with the particle volume fraction are investigated by using Finite Element Analysis of Ansys Mechanical APDL. A 2D micromechanics model based on variation asymptotic method for unit cell (VAMUCH) was employed for this study. The research study comprises of two cases: (1) the comparison of different size of glass particle filler from nano to micro size, and (2) the comparison of volume fraction of glass particle ranging from 5 to 25 vol% towards the mechanical properties of epoxy resin. The results of the first case study demonstrated that the stress and strain against gradient displacement is slightly increased for all modelling samples. In fact, the smallest area size particle of 7.85 nm² produces the highest value of Young’s modulus 3.66 GPa. Similarly, for second case study, it is found that the highest Young’s modulus 5.14 GPa was achieved at 10 vol% glass particles, which is about 91% increment compared to unfilled epoxy. Therefore, concludes that as the size of glass particle getting smaller from macro to nano size, and the volume fraction of glass to epoxy is lower, then the Young’s modulus of composite increases.