Constitutive Parameters and their Evolution

The three dimensional problem of anisotropic evolution is formulated and solved using the tools from optimal design. Basic assumptions are the principle of maximum energy dissipation and a function that relates the damage, as measured by the rate of a constitutive matrix norm, to an effective stress measure. The presentation relies on alternative description for the 21 constitutive parameters and only restricts the constitutive matrix to be semi-positive definite.