Introduction

In the earlier lectures we have used the effective properties of the unidirectional layers in the development of various lamina or laminate mechanics issues. However, we know that at microscale the fibrous composites are heterogeneous. A composite is made of two main phases - fiber and matrix. Further, we know that apart from these two phases, additional phase may be present in the composite. These phases may be fillers, zones formed due to reaction between fibre and matrix and the coatings applied to the fiber, if any. The properties of these constituents, their amounts present and their distribution affect the effective properties of the composite.

It is now well understood that to determine the effective properties of a composite one needs to consider the microscale, that is, the scale at which the fibre and matrix are present. Thus, the study of composites at the fiber and matrix level is referred to as micromechanics.

In the present lecture we will present various methods to determine the effective hygro-thermo-mechanical properties of the composite. It is assumed that the properties of constituents, their arrangements and amounts are known a-priori.

The Lecture Contains