Device for carrying out optical non-destructive testing on surface of annular inner wall

Abstract

The invention relates to a device for carrying out optical non-destruction testing on the surface of an annular inner wall, which is characterized in that a fine glass rod, a beam expanding device, a shearing element, an imaging device, a linear array CCD and a rotary table are sequentially arranged on an axis line of the tested annular inner wall; the sharing element, the imaging device and the linear array CCD are fixed on the rotary table, and a primary optical axis of the linear array CCD is coincided with a rotation axis; the fine glass rod is arranged on the axis line of the annular inner wall with the distance of less than 200mm to the center of the annular inner wall and arranged in parallel with the axis line of the annular inner wall; an optical axis of a laser is placed by leading the angle between the optical axis and the central axis line of the glass rod to be 0.01 degree-20 degrees; and image signals collected by the linear array CCD are outputted to a computer, and a control signal of the computer is outputted to the rotary table for controlling the rotation of the rotary table. The linear array CCD is utilized for push-broom, a mobile track of a micro-displacement platform is designed according to the surface of a tested sample, and a speckle pattern obtained by push-broom along the mobile track can eliminate the defocus phenomenon of a speckle image and improve the sensitivity of defect detection.

Description

technical field [0001] The invention relates to a device for optical non-destructive testing of the surface of an annular inner wall, which belongs to the technical field of optical non-destructive testing. Background technique [0002] Digital shear speckle interferometry is a laser-based full-field, non-contact measurement of surface deformation (displacement or strain). A shearing mirror with a small wedge angle is placed in front of the imaging lens, so that a point on the surface of the object produces a pair of two images with a small misalignment on the image plane. Since the surface of the object is illuminated by the laser, the image caused by the misalignment The two clipped images interfere with each other to form a clipped speckle field containing a random interference pattern. The dislocation images interfere with each other on the image plane to form a speckle interference image, which is collected by the CCD into the computer through the image card, and the t...

AI Technical Summary

Problems solved by technology

Therefore, non-destructive testing based on area array CCD cannot meet the requirements of large field of view and high sensitivity at the same time.

In addition, if the surface of the material to be tested has large fluctuations, exceeding the depth of field limit of the imaging system, and the area array CCD is a quasi-plane, part of the image formed on the surface of the area array CCD will be defocused

Due to the influence of the image recording medium, the sensitivity and resolution of digital shear speckle interferometry cannot be further improved

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