Damage evolution and constitutive behavior of advanced composites

The aim of this paper is to present a mechanics based theory that accounts for damage evolution in advanced composites. Single-ply behavior, under various loading conditions, is studied in detail herein. It is shown that the proposed theory can capture the essential deformational characteristics of single composite material plies, subjected to external load. Emphasis is placed on the properties of the theory and its capability to predict the observed behavior; further, the present approach is compared to classical analysis procedures. The paper extends previous work by the first author; it considers loading path effects, relation of damage growth to apparent Poisson ratio, strain based distinction between tension and compression, failure criteria under different loading conditions, and thermodynamic restrictions.