ABSTRACT
Continuum mechanics is used to describe deformation and stress in an orthotropic material. The stress vector associated to a plane passing through a point is the force per unit area acting on the plane passing through the point. A second-order tensor, called the stress tensor, completely describes the state of stress at a point. The solution of problems in solid mechanics requires that boundary conditions be specified. The boundary conditions may be specified in terms of components of displacement, stress, or a combination of both. All elastic energy stored during loading is recovered during unloading. Therefore, the elastic energy at any point on the stress-strain curve is independent on the path that was followed to arrive at that point. Further restrictions on the values of the elastic constants can be derived from the fact that all diagonal terms in both the compliance and stiffness matrices must be positive.
