Evolution of effective mechanical and interphase properties during natural ageing of glass-fibre/epoxy composites using micromechanical approach

Abstract

This work proposes, by a micromechanical approach, to simulate the effects of humid tropical aging on a unidirectional composite (E-glass fibers/epoxy) by taking into account an interphase region. An interphase area (500 nm width) is identified by AFM measurements around each fibre at the initial state. During the ageing this area increases up to 1 µm width. Numerical micro-models, using ABAQUS™, are developed to predict the mechanical behaviour of the composite under monotonic transverse traction. A Representative Volume Element description with a random distribution of the fibres is generated from the plug-in “RVE for Composites”. Linear elastic behaviour laws are used to describe the behaviour of materials and Kinematic Uniform Boundary Conditions are considered to describe the boundaries conditions. Numerical, analytical and experimental results are compared to validate the micro-models. The obtained results are in good agreement with the analytical and experimental values. These results highlight the importance of taking composite interphase into account in numerical models for mechanical behaviour.