High-precision ultrahigh temperature video extensometer and measurement method thereof

Abstract

The invention relates to a high-precision ultrahigh temperature video extensometer and a measurement method thereof. The high-precision ultrahigh temperature video extensometer comprises an ultraviolet camera (17), a coaxial telecentric imaging system (5), a monochromatic light source (12), a narrow band-pass filter (14) which is corresponding to the wavelength of the monochromatic light source, a mechanical support adjusting platform (6) and a computer (13). High-temperature-resistant speckles are manufactured on the surface of a test piece or a special test member of which the edge has four bosses is adopted. A high temperature testing machine having an observation window is utilized to apply force and thermal load to a measured rectangular section or circular section test piece. The test piece is actively lighted by coaxial ultraviolet light, and surface video images of the test piece are acquired by the high temperature video extensometer. High-precision real-time measurement is performed on the strain of the surface of the test piece by utilizing a digital image correlation method. The video extensometer is simple in principle and compact in structure and can be cooperated with the high temperature testing machine to perform real-time and high-precision measurement on deformation and mechanical properties of the surface of the test piece under the environment from room temperature to ultrahigh temperature of 2000 DEG C.

Description

technical field [0001] The invention relates to the field of experimental solid mechanics, in particular to a high-precision ultra-high temperature video extensometer based on digital image correlation and a real-time strain measurement method. Background technique [0002] At present, there are mainly two types of methods for strain measurement under ultra-high temperature conditions: contact method and non-contact method. The traditional contact method usually uses a contact ultra-high temperature extensometer to measure high-temperature strain, but the measurement of this ultra-high temperature extensometer needs to open a hole in the furnace, and the deformation of the high-temperature area in the furnace is transferred to the outside through the extension rod. low temperature area. However, the opening makes the design and heat insulation of the furnace difficult. In addition, the range of the ultra-high temperature extensometer is relatively limited, and it is impossi...

AI Technical Summary

Problems solved by technology

[0005] In order to solve the problem that the existing technology cannot meet the real-time high-precision strain measurement requirements at ultra-high temperature, the present invention proposes a real-time high-precision ultra-high temperature video extensometer and strain measurement method based on digital image correlation, which avoids speckle Spraying, can withstand extremely high temperature, fast calculation speed, high precision

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