Measuring method of mechanical damage in brittle materials based on in situ x-ray tomography

Abstract

The invention discloses a measurement method for mechanical injury of a brittle material based on in-situ X-ray tomography. The method comprises the following steps: step (10), fixing a brittle material sample on a in-situ loading unit; step (20), firstly testing the X-ray tomography of the brittle material sample to obtain three-dimensional tomographic image data G1 (x, y and z); step (30), performing in-situ online mechanical injury on the brittle material sample to obtain an injury sample and record the deflection; step (40), secondly testing the X-ray tomography of the brittle material sample to obtain three-dimensional tomographic image data of the injury sample to perform three-dimensional digital image interpolation processing, wherein three-dimensional data is G2 (x, y and z) after interpolation; step (50), selecting the size of subsets; step (60), measuring the average (shown in the specification) of gray scale of voxels in a G1-subset (x, y and z) and a G2-subset (x, y and z); and step (70), obtaining the three-dimensional spatial distribution of the mechanical injury of the injured sample. The measurement method can accurately obtain the spatial distribution of the three-dimensional local injury variable of the brittle material.

Description

technical field [0001] The invention belongs to the category of damage mechanics and experimental mechanics of various brittle materials, and specifically relates to a method for measuring mechanical damage of brittle materials based on in-situ X-ray tomography. Background technique [0002] Brittle materials such as cement concrete, ceramics, rocks, masonry, and resins are widely used in production and life. However, during the service process of mechanical loads, the deterioration of the organizational structure of such materials, such as microstructural defects such as microcracks, will inevitably occur. The irreversible changes such as the initiation and expansion of micropores, micropores, etc., which cause the deterioration of the macroscopic mechanical properties of materials or structures, are called damage in damage mechanics. [0003] Damage mechanics mainly studies the mechanical laws of materials or components under various service conditions, in which damage evo...

AI Technical Summary

Problems solved by technology

The first type of method is similar to traditional microscopic observation, but the resolution of X-ray tomography is not enough to resolve small cracks, so the extent of damage is seriously underestimated

The disadvantage of the second type of method is that it is impossible to separate deformation and damage. Because of the existence of degeneration, the two tests before and after are not in the same area at all, and the direct difference is inaccurate. In addition, this method cannot give the space of three-dimensional damage variables. distributed

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