ON TWO-DIMENSIONAL SELF-CONSISTENT MICROMECHANICAL DAMAGE MODELS FOR BRITTLE SOLIDS

Two-dimensional self-consistent micromechanical damage models are presented for microcrack-weakened brittle solids under "cleavage I" deformation processes. The proposed framework basically follows the previous work of Horii and Nemat-Nasser (1983. J. Mech. Phys. Solids 31(2). 155-171) and Sumarac and Krajeinovic (1987, Mech. Mater. 6, 39-52). Thermodynamic basis. microcrack opening displacements and damage-induced inelastic compliances are derived. Microcrack evolutions (growth) are characterized through the use of fracture mechanics stability criteria and microstructural microcrack geometry. Mode I, mode II and mixed mode microcrack growth are considered. Simple and efficient computational algorithms as well as three detailed numerical simulations are also presented to illustrate the potential capability of the proposed micromechanical damage models. In particular. no fitted "material parameters" are needed. Moreover. loading, unloading stress paths and microcracks status changes in opening; closing are trivially. accommodated in this work.