EFFECTIVE ELASTIC-MODULI OF 2-DIMENSIONAL BRITTLE SOLIDS WITH INTERACTING MICROCRACKS .2. EVOLUTIONARY DAMAGE MODELS

In Part I of this series, basic formulations of stationary micromechan ical theory and overall responses are presented for two-dimensional br ittle solids with randomly dispersed microcracks. The basic formulatio ns hinge on an ensemble average approach which includes pairwise micro crack interactions. In this paper, statistical micromechanical evoluti onary models are proposed to account for ''cleavage 1'' growth of rand omly oriented and located microcracks under microcrack interaction eff ects. Biaxial tension/compression loadings are also considered to take into account mixed microcrack opening and closure effects. Efficient numerical integration algorithms for the proposed ensemble averaged co nstitutive equations are subsequently given. Further, uniaxial and bia xial tests are presented to illustrate the proposed models and procedu res. Finally, a higher-order microcrack interaction model within the p roposed micromechanical framework is discussed.