Method for establishing crystal plastic constitutive model of face-centered cubic material in fatigue process

Abstract

The invention discloses a method for establishing a crystal plastic constitutive model in the fatigue process of a face-centered cubic material. The invention solves the problem that mesoscale plastic evolution and material microstructure characteristics cannot be considered in the calculation of material damage and fatigue failure, and provides a more accurate and innovative mesoscopic crystal modeling method and crystal plastic constitutive model and related stable and efficient calculation method. The crystal plastic constitutive model and calculation method proposed by the present invention take into account the normal direction and slip direction of the crystal slip surface, use the motion and isotropic hardening criteria to consider the back stress effect, and finally establish the crystal slip and dislocation density and plastic shear A constitutive model for crystal plasticity of face-centered cubic metallic materials as a function of shear strain rate. It can study the influence and contribution of material microscopic characteristics on material damage and fatigue life from the mesoscopic scale, and provide important theoretical guidance and technical support for the study of material damage evolution and fatigue failure process, which has important scientific significance and engineering application value.

Description

technical field [0001] The invention relates to the technical field of material fatigue failure, in particular to a method for establishing a crystal plastic constitutive model in the fatigue process of a face-centered cubic material. Background technique [0002] Reliability and long life are the core issues in the service process of materials. Research has shown that fatigue is one of the leading causes of failure in mechanical components and industrial equipment. Statistical analysis shows that more than 80% of mechanical failures are caused by fatigue. Fatigue failure is latent and sudden, and it will also have a certain impact on adjacent components. Therefore, fatigue failure is a very complex physical phenomenon of material-mechanical interaction. Usually, the failure of materials starts from the grain or grain boundary, and after a period of plastic deformation, visible microscopic cracks are formed on the slip zone. A large number of microscopic cracks fuse with ...

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Problems solved by technology

[0005] Aiming at the above-mentioned deficiencies in the prior art, the present invention provides a method for establishing a crystal plastic constitutive model in the fatigue process of face-centered cubic materials, which solves the problem that mesoscopic plastic evolution and material microstructure characteristics cannot be considered in the calculation of material damage and fatigue failure. question question

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