A damage constitutive model for the whole process of joint shear based on the determination of yield point based on stress difference

Abstract

The invention discloses a joint shearing whole-process damage constitutive model for determining a yield point based on a stress difference. The method comprises the steps that S1, setting a joint thin-layer microscopic unit body to be loaded and then enters a linear elasticity stage, the joint thin-layer microscopic unit body is an isotropic continuous medium, the microscopic unit body is instantaneously completed when being converted from a lossless state to a lossy state, and the process is irreversible; S2, defining an external load threshold F * based on a Weibull distribution function toobtain a damage probability density function of the mesoscopic unit body; S3, based on a rheological model mechanical element, simulating the load condition of a mesoscopic unit body by adopting thecombination of a spring and a friction plate to obtain a statistical damage constitutive model of the joints under the shearing action; S4, determining an external load threshold F * according to twoparts, namely damage and non-damage, of the rock and soil material after being subjected to load damage, and obtaining a damage evolution model and a joint shear deformation damage constitutive modelof the joint in the shear deformation process; S5, determining parameters m, u0 and us of the joint shear deformation damage constitutive model; and S6, verifying the correctness of the constitutive model.

Description

technical field [0001] The invention belongs to the technical field of rock shear surface characteristics, and in particular relates to a damage constitutive model of the whole process of joint shearing which determines the yield point based on the stress difference. Background technique [0002] Natural rock mass has experienced complex geological processes during its formation, and there are various types of joints with different properties inside. The failure mechanism of engineering rock mass is largely controlled by joints, and the mechanical properties of joints are mainly affected by their shear strength. Controlling the shear properties of joints is a key scientific and hot issue in rock mechanics research. For a long time, the focus of joint shear theory research is to establish a constitutive model that can accurately reflect the mechanical properties of joints and the whole process of shearing. Scholars at home and abroad have conducted a large number of experime...

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Problems solved by technology

[0020] The purpose of the present invention is to address the above-mentioned deficiencies in the prior art, to provide a joint shear damage constitutive model for the whole process of joint shearing based on the stress difference to determine the yield point, so as to solve or improve the above-mentioned problems

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