ABSTRACT
Laminated composites are typically constructed from orthotropic plies (laminae) containing unidirectional fibers or woven fabric. Generally, in a macroscopic sense, the lamina is assumed to behave as a homogeneous orthotropic material. The constitutive relation for a linear elastic orthotropic material in the material coordinate system (Figure 2.1) is (Daniel and Ishai 2006, Gibson 2007, Herakovich 1998, Hyer 2009, Jones 1999, Reddy 1997)
ε
ε
ε
γ γ γ
=
σ
σ
σ
τ
τ
τ
S S S S S S S S S
S S
S
0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
(2.1)
where the stress components σi, τij are defined in Figure 2.1, and the Sij are elements of the compliance matrix. The engineering strain components εi, γij are defined as implied in Figure 2.2.
