Speckle interference-based synchronous deformation and strain measurement system and method

Abstract

The invention provides a speckle interference-based synchronous deformation and strain measurement system and method, and relates to the technical field of optical test. The system is characterized bycomprising a laser and a beam splitter; the laser light emitted by the laser is divided into transmitted light and reflected light by the beam splitter; the transmitted light is expanded by the beamexpander and then irradiated to a measured object to form diffuse reflected light; the reflected light passes through an optical fiber and a beam splitter prism in sequence to enter an optical path asreference light; the diffuse reflected light passes through a diaphragm, an imaging lens, the beam splitter prism and a Michelson shearing device in sequence to obtain two beams of object light having shear amounts; the reference light introduced by the optical fiber passes through the Michelson shearing device to obtain two beams of reference light having shear amounts; the two beams of object light having the shear amounts and two beams of reference light having the shear amounts interfere each other on the target surface of a CCD camera so as to form a speckle interference diagram. The system can perform synchronous dynamic detection of speckle and shear on the tested objects, and is a non-destructive, full-field and high-precision measurement system.

Description

technical field [0001] The invention relates to the technical field of optical testing, in particular to a deformation and strain synchronous measurement system and measurement method based on speckle interference. Background technique [0002] Both digital speckle interferometry and digital shear imaging are real-time, full-field, non-contact optical measurement methods, which have been widely used and played an active role in the non-destructive testing of composite materials in the automotive and aerospace industries in recent years. Among them, the speckle interferometry system can only measure deformation information, while the digital shear imaging system measures the first derivative of deformation, that is, strain information. In practical applications, both deformation information and strain information are key parameters for defect detection and evaluation. [0003] In general, deformation and strain can be converted into each other. Deformation can be calculated...

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Problems solved by technology

However, purely numerical calculations are usually more complicated, and errors are easy to accumulate, and ideal results cannot be obtained

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