Testing device for static/dynamic metal shearing behavior

Abstract

The invention discloses a testing device for static / dynamic metal shearing behavior. A prepared convex test sample is applicable to dynamic and static shearing behavior testing both, speckle spots can be manufactured on the surface of the convex test sample, acquired data can be calculated by using a digital image relevant method, and then relevant data of a test sample deformation strain field can be obtained. By adopting the method, the operation test sample area shearing and the whole process of shearing deformation can be directly observed. The data calculation process comprises the following steps: by taking a first speckle spot image without deformation as a reference image and other images as deformation images, selecting an area of which the strain is required to be calculated from the reference image, and at the same time selecting a relevant calculation window in the area of which the strain is required to be calculated; determining an appropriate calculation step length according to the resolution of the image, and moving the relevant window to a relatively small strain influence area in the area of which the strain is required to be calculated as a calculating starting point, and starting displacement calculation; after the calculation is completed, selecting points, lines and shearing areas for data analysis according to experiment requirements.

Description

Technical field [0001] The present invention relates to the field of measurement technology, in particular to a testing device for dynamic and static shear behavior of metals. Background technique [0002] In the measurement of metal shearing behavior, not only the dynamic shearing behavior must be measured, but also the static shearing behavior sometimes needs to be measured. In the prior art, the static shearing behavior and the dynamic shearing behavior need to be tested differently. Test device. [0003] The measuring devices used to measure the dynamic shear behavior of metals are as figure 1 As shown, the loading device is composed of a Hopkinson pressure bar, which is divided into an incident bar and a transmission bar, and strain gauges are attached to the incident bar and the transmission bar. The measurement sample is usually a cap type specimen, which is sandwiched between the incident rod and the transmission rod. The bullet hits the incident rod at high speed, and th...

AI Technical Summary

Problems solved by technology

The camera can also be used in the measurement of static shear behavior, but the camera can only take images of the deformation process and results of the sample after being squeezed, and provide them to the tester for viewing, but cannot automatically use the captured images for calculation , so as to obtain the data related to the strain field

[0005] It can be seen that in the dynamic shear behavior test method, the data is collected indirectly through the strain gauges on the incident rod and the transmission rod, and the data is inaccurate; in addition, the sample is a hat-shaped structure, and the shear area is located inside, so it cannot be directly observed In the shear area of ​​the sample, in order to observe the internal deformation of the hat-shaped sample, the hat-shaped sample needs to be cut; at the same time, the high-speed camera can only capture the image of the extruded external state of the hat-shaped sample, and cannot obtain dynamic shearing. The change process of the shear plane when cutting

[0006] In addition, the existing technology needs to use different devices to test the dynamic and static shear behavior of metals. The shapes of the test samples loaded in the static test and the dynamic test are different, which leads to the need to make different samples, which increases the production cost. In addition, the The preparation of type samples is also more troublesome

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