Fibre-reinforced composites have many outstanding advantages that attract commercial industries to use them such as, automotive industry, aerospace industry, marine industry, wind turbines, and sports goods. Fibre-reinforced composites characterised as a high strength/stiffness to weight ratio comparing with natural metals resulting in very lightweight structures which in turn reduce fuel consumed by aircraft, for instance. They also provide an excellent resistance to, corrosion, fatigue stress, impact force and chemical attack. The main concern in use of these materials is the complexity of damages that are taken place in different scale lengths starting from micro-scale level. With the development of computer power, however, the door is opened to enhance concepts such as a multi-scale analysis that can bridge microscale to macro-scale. The new tools provide excellent substitutes of the costly and time-consuming experimental tests.
In this thesis, Discrete Element Method (DEM) is developed for micromechanical modelling of fibre-reinforced composites. In Chapter 2, a new method is proposed for generating random fibre distribution. Unlike prior methods that have proposed, this method can be used to generate a high fibre volume fraction with any inter-fibres distance.
The new method is then applied throughout the thesis. In Chapter 3, a Representative Volume Element (RVE) containing fibres distributed randomly subjected to uniaxial transverse tension is studied. The DEM is showed to a genuine tool to investigate damage propagation in fibre-reinforced composites.
Chapter 4 is dedicated to determining the elastic properties of the fibrereinforced composite using DEM. The results are then compared with selected analytical methods, namely Voigt and Mori-Tanaka methods, other numerical method such as Finite Element Method (FEM), and experimental results.
The methodology developed in previous chapters are then adopted in Chapter 5 to study the failure of fibre-reinforced composite under uniaxial compression, transverse shear and biaxial transverse loads. Results are compared with experiments and analytical method such as Hashin and Puck models.