STRAIN GAGING METHOD Russian patent published in 2017 - IPC G01B11/00 

FIELD: measuring equipment.

SUBSTANCE: strain gaging method comprises the marking the test part with two colour marks over a distance of a test part initial reference length on the basis of its sizes, the test part digital image acquisition with the help of the colour-video camera and the test part marks obtaining in the standard palette of red R, green G and blue B colours (sRGB). One sets the criteria value for the detection of the appropriate pixels, that belong to the marks colour, by the virtue of the statistical distribution of the intensity of the pixel colour constituents of the whole image. The method also comprises the finding for the selection of the colour marks the maximum gathering pixel of the same colour and the nearest boundaries detection. One calculates the pixels number value (distance) as the difference between the smallest and the biggest value among these boundaries in the coordinates of its location in the digital image. This is the way, how one calculates the length of marks, spread on the test part, and also how one processes every frame, received from the digital video camera. One calculates the strain after obtaining the second and the subsequent image frames as the difference between the length of marks of the first frame and the length of marks of every subsequent frame. One compares the calculated strain value in pixels to the strain gaging unit. These values are written to the array for the following analysis.

EFFECT: creation of the automatically controlled method of the strain gaging in the process of the plastical deformation tests of the items made of the parent sheets, cylindrical works and massive work parts.

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