Parameter identification method for constitution and failure model of material under ultra-high strain rate

Abstract

The invention discloses a parameter identification method for a constitution and failure model of a material under an ultra-high strain rate. A dynamic stress-strain curve of the deformation and failure process of the material under a high strain rate is obtained through Hopkinson pull rod test, and the dynamic stress-strain curve of the material under the high strain rate is used as a target forreverse optimization fitting to obtain parameters of the constitution and failure model after the first optimization are obtained; a light gas gun system is used to perform high-speed ballistic impacttests on the material, a high-sensitivity strain gauge is used to monitor the dynamic stress-strain curve of the material near a damage zone, and the feature size of a damage notch can be measured bya scanning electron microscopy; ballistic impact test parameters are used as boundary conditions for ballistic impact numerical simulation, and the dynamic stress-strain curve of the material corresponding to the position of the high-sensitivity strain gauge and the feature size of the damage notch can be extracted; the actually tested dynamic stress-strain curve of the material and the actuallytested feature size of the damage notch are used as targets for reverse optimization fitting to finally obtain the parameters of the constitution and failure model of the material under the ultra-highstrain rate.

Description

technical field [0001] The invention belongs to the technical fields of material testing, numerical simulation, optimization methods and the like, and in particular relates to a parameter identification method of material constitutive and failure models under ultra-high strain rates. Background technique [0002] Under the action of external force, the metal material first undergoes elastic deformation, and when the stress exceeds the yield strength of the material, it will undergo plastic deformation. The dynamic stress-strain relationship of the material during the elastic-plastic deformation process can be described by a constitutive model; when the strain increases to a certain Afterwards, the material begins to suffer damage and failure until it finally breaks. The plastic strain at the time of fracture is the maximum plastic strain of material failure. The damage evolution behavior of the material during the entire failure process is described by the failure model. , i...

AI Technical Summary

Problems solved by technology

However, the model parameters identified by this method cannot accurately represent the dynamic deformation and failure behavior of materials with ultra-high strain rates during the process of foreign object damage, which leads to prediction errors in the damage defect morphology and local stress field distribution of blades after foreign object damage is large, therefore, a parameter identification method for material constitutive and failure models at ultra-high strain rates is needed

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