Method for identifying plastic mechanical parameters of metal material by adopting spherical indentation morphology

Abstract

The invention discloses a method for identifying plastic mechanical parameters of a metal material by adopting spherical indentation morphology, which comprises the following steps of: acquiring an indentation experiment outline snapshot remained on the surface of a test piece, establishing an indentation outline snapshot matrix, establishing a subspace of the indentation outline snapshot by adopting an orthogonal decomposition algorithm, and realizing direct association of the material plasticity mechanical parameters and the indentation contour snapshot subspace coordinates in the subspace; and defining a difference allowable value between the indentation experiment contour snapshot and a series of simulation contour snapshots in the subspace, and obtaining the identification result of the mechanical property parameters of the tested material according to the distribution characteristics of the difference allowable value in the material parameter interval. During material parameter identification, a series of direct comparison between indentation contour data obtained through prediction and indentation experiment contour data is used, the purpose of material parameter identification is achieved, the possible parameter identification local optimum problem in the large-scale numerical iteration process is avoided, and the method is higher in efficiency and more reliable.

Description

technical field [0001] The invention belongs to the technical field of testing methods for plastic mechanical properties of materials, and in particular relates to a method for identifying plastic mechanical parameters of metal materials by adopting spherical indentation morphology. Background technique [0002] An in-depth understanding of the basic mechanical properties of materials is the prerequisite for material mechanics modeling, structural design and material forming process analysis. Therefore, how to accurately obtain the basic mechanical properties of materials has always been a hot issue in the field of material performance testing. For the detection of plastic mechanical properties of materials, the existing conventional mechanical experiment methods mostly use uniaxial tension / compression testing. This test method needs to cut the test piece according to a certain geometric standard, and then use the destructive tension or compression process to obtain the pla...

AI Technical Summary

Problems solved by technology

However, the parameter identification process of iterative optimization often requires large-scale calculations involving the gradient of the objective function, which usually leads to non-convergence of iterative calculations.

Moreover, the parameter identification process based on gradient optimization can only obtain point estimation results of material performance parameters, and it is difficult to judge the uniqueness of the identification results and the credible distribution interval of material properties around the estimated points

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