On interaction between damage growth and material stiffness in 3D structures

Deterioration of material properties; such as, rupture toughness, strength, and rigidity as well as lifetime reductions are modelled by a symmetric second order damage tensor introduced into the constitutive description, when employing the theory of tensor function representations. The growth of damage and state of failure are described by a one parameter model of damage evolution and a three parameter failure criterion. The constitutive description for different modes of failure front propagation is of particular interest in this study. The comparison between solutions obtained by means of two different physical models; i.e., the linear elastic and linear elastic with damages ones, respectively, has been presented. In both cases the stress redistribution due to geometrical changes of the structure induced by the crack propagation has been considered. Numerical calculations have been made employing the ABAQUS programme, Runge-Kutta procedures for integration of the evolution equations, standard methods of matrix division in LU decomposition and Gauss method for solving the set of linear equations.