A variable four-parameter damage constitutive structure of concrete under multiaxial stress state

Abstract

The invention discloses a multi-axial stress state concrete variable four-parameter damage constitutive structure which comprises the following steps: 1) carrying out a strength test on a concrete sample to obtain a stress-strain full curve of the concrete sample; 2) solving four parameters of a loading process according to the stress-strain full curve, and calculating corresponding equivalent stress-strain; 3) according to the change process of the four parameters and the equivalent strain, fitting a function of the four parameters about the equivalent strain. The problem that the differencebetween the descending sections of different test stress-strain curves is large can be solved, and the expression situation of the softening section of the concrete in the multi-axial stress state canbe better simulated.

Description

Technical field[0001]The invention belongs to the technical field of concrete constitutive models, and specifically relates to a four-parameter damage constitutive of concrete in a multiaxial stress state.Background technique[0002]Concrete is a heterogeneous multiphase mixed material. It is generally considered that at a macroscopic scale greater than three times the aggregate size, concrete can be regarded as an isotropic homogeneous material; at the meso level less than three times the aggregate size The upper part is composed of cement mortar, coarse aggregate and cementing surface. Aggregate particles and internal cracks need to be considered. When analyzing the mechanism of concrete deformation and fracture, the viewpoint of meso-level is mostly adopted. It is believed that the micro-cracks in the concrete material expand and extend continuously under the external action, forming macro-cracks, until the fracture is destroyed. The existing view is that the propagation of meso-cr...

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Problems solved by technology

[0005] Aiming at the defects existing in the prior art, the present invention provides a multi-axial stress state concrete variable four-parameter damage constitutive, which considers the changes of the four parameters in the concrete loading process, and solves the problem of large differences in the descending sections of the stress-strain curves of different tests , which can better simulate the performance of the softening section of the concrete multiaxial stress state

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