Testpiece quality detection method based on two-dimensional digital image correlation method

Abstract

The invention belongs to the field of optical measurement mechanics, and particularly relates to a test piece quality detection method based on a two-dimensional digital image correlation method.The method comprises the steps of obtaining the speckle spots of a test piece to be tested, establishing a space coordinate system with the center point of the test piece as the origin of coordinates; mapping the spatial speckles on the surface of the test piece into planar speckles; applying an axial tensile force to the test piece to be tested, and collecting a surface speckle pattern of the test piece after deformation; mapping each spatial speckle spot in the surface speckle pattern of the deformed test piece into a planar speckle spot; processing the mapping plane speckles before the deformation of the test piece and the mapping plane speckles after the deformation of the test piece by adopting a reverse combination Gaussian Newton algorithm to obtain a test piece surface deformation measurement result; according to the method for mapping the space coordinate points to the plane coordinate points, the one-to-one correspondence mapping relation between the original coordinate system and the new coordinate system is guaranteed, the calculation amount is small, and programming is easy to achieve.

Description

technical field [0001] The invention belongs to the field of photomechanics, and in particular relates to a test piece quality detection method based on a two-dimensional digital image correlation method. Background technique [0002] Digital image correlation (DIC) is an optomechanical method based on digital image processing technology, which uses shape functions to correlate search and calculation of pre-deformed and post-deformed image sub-areas to obtain each image in the target area. DIC has been successfully applied in many different fields because it only relies on a simple test environment and can obtain the deformation information of the whole field. [0003] At present, two-dimensional DIC technology has good results in terms of calculation accuracy and search speed. However, only relying on two-dimensional DIC technology in the production process cannot meet the needs of industrial measurement, such as the full field of surface deformation of curved specimens. I...

AI Technical Summary

Problems solved by technology

[0003] At present, two-dimensional DIC technology has good results in terms of calculation accuracy and search speed. However, only relying on two-dimensional DIC technology in the production process cannot meet the needs of industrial measurement, such as the full field of surface deformation of curved specimens. In the measurement, only three-dimensional DIC technology can be used, but the three-dimensional DIC technology still needs to be improved in terms of calculation accuracy and search speed

Images