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...

Images