Method for obtaining yield criterion of polycrystalline metal material

Abstract

The invention provides a method for obtaining a yield criterion of a polycrystalline metal material, comprising the following steps of: S1, obtaining tensile and compressive mechanical property curvesof a polycrystalline material; S2, measuring texture orientation distribution data of the polycrystalline material, and carrying out block component processing on the orientation distribution data; S3, calculating to obtain critical shearing force required by activation of initial yield of various deformation mechanisms of the polycrystal according to the obtained mechanical property curve and texture orientation distribution data; S4, specifying a specific loading condition, and calculating the yield strength of each texture component under the condition of considering the intercrystalline deformation coordination effect; S5, calculating the equivalent yield strength under the specified loading condition; and S6, circularly executing the steps S4 and S5 until all loading conditions are traversed to obtain the equivalent yield strength of the polycrystalline material under all loading conditions and obtain the yield criterion of the polycrystalline material. The method has advantagesof high accuracy of the yield criterion, small calculated amount and strong practicability.

Description

technical field [0001] The invention relates to the field of material technology, in particular to a method for obtaining yield criteria of polycrystalline metal materials. Background technique [0002] The yield criterion is mainly used to predict the yield strength of the metal material under different loading conditions. Usually, the yield criterion of the metal material is referred to when formulating the design safety work standard of the metal material under the duplication condition, so the accuracy of the yield criterion is very important . [0003] The traditional yield criterion is mainly based on the mechanical properties of traditional materials such as steel and aluminum alloys, and is established by fitting test results with phenomenological methods. Most of these materials have isotropic characteristics, that is, to measure the yield strength of materials under one condition, It can be used as the equivalent yield strength under other conditions; this yield c...

AI Technical Summary

Problems solved by technology

However, since it is necessary to fully understand the behavior of microstructure changes during deformation of polycrystals and to fully consider the activation conditions of all possible deformation mechanisms in polycrystals, a yield criterion with sufficient precision can be established, leading to the polycrystal yield criterion of the form It is very complicated, the amount of calculation is very large, and the calculation efficiency is low, so it is difficult to popularize and apply in actual production

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