Classical Laminate Theory:

 The classical laminate theory is a direct extension of the classical plate theory for isotropic and homogeneous material as proposed by Kirchhoff –Love (see [1, 2] for details). However, the extension of this theory to laminates requires some modifications to take into account the inhomogeneity in thickness direction. In the following, the assumptions made in this theory along with the assumptions made for classical plate theory are given.

Assumptions of Classical Lamination Theory:

1. The laminate consists of perfectly bonded layers. There is no slip between the adjacent layers. In other words, it is equivalent to saying that the displacement components are continuous through the thickness.

2. Each lamina is considered to be a homogeneous layer such that its effective properties are known.

3. Each lamina is in a state of plane stress.

4. The individual lamina can be isotropic, orthotropic or transversely isotropic.

5. The laminate deforms according to the Kirchhoff - Love assumptions for bending and stretching of thin plates (as assumed in classical plate theory). The assumptions are:

1. The normals to the mid-plane remain straight and normal to the midplane even after deformation.

2. The normals to the mid-plane do not change their lengths.

The classical laminate theory is abbreviated as CLT. This theory is known as the classical laminated plate theory and abbreviated as CLPT.