Optical measurement method for strain rate field inside object with parallel front and back surfaces

Abstract

The invention discloses an optical measurement method for a stain rate field inside an objected with parallel front and back surfaces.The method comprises the steps that velocity fields of measuring points on the front and back surfaces of the loaded object with the parallel front and back surfaces are obtained through a digital image relative method at first; the object with the parallel front and back surfaces is divided into gap-free voxel cuboids which are arranged in rows and columns without being stacked and with measuring points are top points, each voxel cuboid is simplified into a hollow voxel cuboid formed by four voxel tetrahedrons, the measuring points on the front and back surfaces are the top points of the voxel tetrahedrons, and the stain rate of each voxel tetrahedron is calculated based on the velocity field of the top point of the voxel tetrahedron; the stain rates of the voxel cuboids are calculated based on the stain rates of the voxel tetrahedrons, and then the stain rate field inside the object with the parallel front and back surfaces is obtained.The optical measurement method is simple in calculation, has the advantages of being high in measurement precision and low in measurement condition, has the wide application prospect in the field of solid experimental mechanics, and is of great benefit to preventing landslide, rockburst and other disasters.

Description

technical field [0001] The invention relates to an optical measurement method for the strain rate field of an object, in particular to an optical measurement method for the internal strain rate field of an object whose front and rear surfaces are parallel. Background technique [0002] Optical measurement technology is a new testing technology that has developed rapidly in recent years. Its important features are non-contact, full-field measurement, high measurement sensitivity and large dynamic range in time and space. The digital image correlation method is a popular optical measurement technology, which can measure the in-plane and out-of-plane displacement of objects. It has the characteristics of low test conditions, wide range of test area and range, and the accuracy can reach 1% of the measured pixels. . [0003] The basic principle of the digital image correlation method is to correlate the two speckle images collected before and after the deformation to realize the...

AI Technical Summary

Problems solved by technology

At present, there is little research on the measurement technology of the internal strain rate field of objects with parallel front and rear surfaces based on the digital image correlation method, especially for the measurement technology of the internal strain rate field of objects with parallel front and rear surfaces but different deformation of the front and rear surfaces

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