Method for establishing tension-compression asymmetric failure criterion of isotropic material

Abstract

The invention discloses a method for establishing a tension-compression asymmetric failure criterion of an isotropic material. The method relating to the aviation resin-based composite material fieldcomprises the following steps: (1), carrying out uniaxial tension, compression and pure shear tests on an isotropic material; (2), establishing a failure criterion in a compressive stress state, and considering an inhibition effect of the compressive stress state on material failure based on a stress invariant theory; (3), establishing a failure criterion in a tensile stress state, and establishing the failure criterion in the tensile state based on an energy method theory; and (4), performing model verification: carrying out test verification on the failure envelope surface described by the tension-compression asymmetric failure criterion through biaxial and triaxial tests of various materials. The method has the beneficial effects that the failure criterion provided by the invention is clear in physical significance, the failure envelope surface of the tension-compression asymmetric isotropic material can be accurately predicted, and different influences of tension and compression stress on material failure are fully reflected.

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 ...

AI Technical Summary

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

Images