A method for measuring the yield surface of metal materials

Abstract

The invention discloses a method for measuring a yield surface of a metal material. The method utilizes a prestretching-torsion deformation loading path to determinate a later yield surface evolution rule and comprises (1) preparing a stretching-torsion combined test sample according to material mechanical test standards, (2) determining a stretching and torsion stress-strain curve and determining stretching and torsion yield strength values, (3) determining an initial yield surface, (4) determining a prestretching-torsion pre-deformation loading path to realize prestretching-torsion pre-deformation loading, (5) determining a later stretching stress-strain curve and determining stretching yield strength after pre-deformation, and (6) determining a later yield surface. The yield surface determined by the loading path has obvious shape change, shows plastic deformation anisotropic behaviors of the metal material in a complex loading way and is especially suitable for metal materials having strong anisotropic mechanical properties.

Description

technical field [0001] The invention belongs to the technical field of measuring the yield surface of a mechanical experiment, in particular to a method for measuring the yield surface of a metal material under different loading paths, and is especially suitable for measuring the metal material of an HCP structure. Background technique [0002] Many problems in engineering applications of metal materials involve the theory of plastic mechanics, such as the processing and forming process of metal materials is plastic deformation. To solve these engineering problems, it is necessary to understand the plastic deformation behavior of materials. A large number of studies have shown that under complex loading paths, the mechanical properties of materials exhibit anisotropic behavior, but the classical plasticity theory cannot characterize such mechanical properties, so it is necessary to describe this behavior. The plastic behavior of metal materials is studied through the evolut...

AI Technical Summary

Problems solved by technology

Although this loading method can effectively determine the shape of the yield surface, it cannot reflect the anisotropic behavior of the plastic deformation of the material well. Therefore, this method is suitable for determining the evolution of the yield surface of isotropic materials, but it is not suitable for Metal materials with strong anisotropic behavior, such as magnesium alloys, titanium alloys, etc.

[0004] In summary, the existing yield surface measurement methods cannot characterize the anisotropy of metallic materials well.

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