中文摘要：

One of fundamental but difficult problems in damage mechanics is the formulation of the ef-fective constitutive relation of microcrack-weakened brittle or quasi-brittle materials under complex loading,especially when microcrack interaction is taken into account.The combination of phenomenological and mi-cromechanical damage mechanics is a promising approach to constructing an applicable damage model with afirm physical foundation.In this paper,a quasi-micromechanical model is preseted for simulating the con-stitutive response of microcrack-weakened materials under complex loading.The microcracking damage ischaracterized in terms of the orientation domain of microcrack growth(DMG)as well as a scalar microcrackdensity parameter.The DMG describes the complex damage and its evolution associated with microcrackgrowth,while the scalar microcrack density factor defining the isotropic magnitude of damage yields an easycalculation of the effects of microcrack interaction on effective elastic moduli.

英文摘要：

One of fundamental but difficult problems in damage mechanics isthe formulation of the ef- fective constitutive relation ofmicrocrack-weakened brittle o quasi-brittle materials under complexloading, especially when microcrack interaction is taken intoaccount. The combination of phenomenological and mi- cromechanicaldamage mechanics is a promising approach to construction andapplicable damage model with a firm physical foundation.