Multi-parameter inversion method and device for heterogeneous materials based on automatic image partitioning

Abstract

The invention discloses a heterogeneous material multi-parameter inversion method and device based on automatic image partitioning. The method includes: making a speckle test piece, fixing the speckle test piece on a testing machine, collecting the original speckle image, and passing the test The machine applies the first load to the speckle specimen, collects M first speckle images; calculates the displacement field, excludes rigid body translation and rigid body rotation, and obtains M corrected second speckle images; on the original speckle image Select the range to be measured; calculate the strain gradient according to the displacement field, automatically divide the range to be measured into the first area to the Nth area, and calculate the elastic-plastic constitutive parameters of the first area to the Nth area respectively. The area to be tested can be automatically divided into multiple areas by calculating the strain gradient, which can automatically complete the area division of the area to be tested in one loading experiment, without the need for manual division by hardness testing and other methods before the loading test, simplifying the elasticity of heterogeneous materials. The process of plastic constitutive parameter measurement.

Description

technical field

[0001] The invention relates to the technical field of optical measurement in experimental mechanics, more specifically, to a multi-parameter inversion method and device for heterogeneous materials based on automatic image partitioning. Background technique

[0002] In the classical parameter inversion method, the specimen is usually a homogeneous material, that is, the material parameters in all regions of the specimen to be tested are consistent. However, in practical applications, there may be differences in the material properties of different regions of the specimen, such as welding materials. At present, the patent application publication number CN102778403A proposes a method for identifying weld material parameters. This method first needs to partition the material according to the results of the hardness test, and then conduct a tensile test, and use digital image correlation technology equipment to obtain each area of ​​the tensile test piece. Real-...

Images