A Method for Establishing Asymmetric Failure Criterion of Isotropic Materials under Tension and Compression

Abstract

The invention discloses a method for establishing an isotropic material tension-compression asymmetry failure criterion. It involves the field of resin-based composite materials for aviation, including the following steps: (1), uniaxial tension, compression and pure shear tests of isotropic materials; (2), establishment of failure criteria under compressive stress state, based on different stress Variable theory, considering the suppression effect of compressive stress state on material failure; (3), establishment of failure criterion under tensile stress state, based on energy method theory, establishing failure criterion under tensile state; (4), model verification, passed The failure envelope described by the tension-compression asymmetric failure criterion was experimentally verified by biaxial and triaxial tests of various materials. Beneficial effects of the present invention: the failure criterion proposed by the present invention has clear physical meaning, can accurately predict the failure envelope surface of tension-compression asymmetric isotropic materials, and fully reflects the different effects of tension and compression stress on material failure.

Description

technical field [0001] The invention relates to the field of resin-based composite materials for aviation, specifically the establishment of failure criteria of resin properties in the mesoscopic model of composite materials, and is also applicable to other isotropic materials with asymmetric tension and compression. Background technique [0002] There are two main methods of constructing a unified failure criterion for isotropic materials, which are based on stress invariant theory and failure surface theory respectively. Among them, the failure criterion based on stress invariant theory has the advantages of simple derivation and strong reliability. The first principal stress invariant (3 times the hydrostatic pressure) is related to the volume change of the material, while the second deviatoric stress invariant is related to the shape change of the material. Almost all failure criteria based on stress invariant are from these two aspects Starting from , its form includes ...

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Problems solved by technology

Beltrami uses the maximum strain energy density to replace the Mises criterion that does not consider the volume change, but in fact the volume expansion energy and distortion energy have unequal effects on the failure of the material, and the material usually does not fail under hydrostatic pressure, so the compressive stress must be considered Inhibitory effect of state on material failure

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