A Statistical Damage Constitutive Model For Brittle Rocks Based On the Lade-Duncan Failure Criterion

Micro-unit strength of rock is randomly distributed based on Lemaitre's strain equivalence assumptions. The paper presents a method for measuring micro-unit strength taking into account the damage threshold. Assuming that the micro-unit strength obeys the Weibull distribution, combined with the Lade-Duncan failure criterion, a new statistical damage constitutive model for brittle rocks is established and the model parameters m and F-0 are determined. The model can simulate the stress-strain relation of full process of rock failure well, especially reflects the influence of different stress on damage threshold and the linear elastic characteristic under low stress for rock. The good accord verifies the validity and feasibility of the new model.