A biaxial residual stress introduction device based on white light interferometry surface topography

Abstract

The invention discloses a biaxial residual stress introduction device based on white light interferometry surface topography, comprising: an upper clamp and a lower clamp, both of which are cross-shaped, and the upper clamp and the lower clamp are Detachable connection, a cross-shaped groove is opened in the middle of the surface of the lower fixture, and a plurality of test piece positioning columns are symmetrically distributed in the cross-shaped groove, and a test piece is placed on the top of the plurality of test piece positioning columns. The top surface of the positioning column of the test piece is in contact with the bottom surface of the test piece; the residual stress introduction device provided by the present invention can apply any two-way tensile stress and compressive stress, the operation is simple, and the value of the residual stress can be artificially controlled , and the application of residual stress does not necessarily cause damage to the specimen. After using the device to apply residual stress and perform indentation, the surface morphology can be observed with a white light interferometer under the premise of maintaining the residual stress without unloading.

Description

technical field [0001] The invention belongs to the technical field of experimental mechanical testing devices, and in particular relates to a biaxial residual stress introducing device based on white light interferometric measurement of surface topography. Background technique [0002] Materials such as ceramics, metals, and glasses are subjected to varying degrees of residual stress due to thermal mismatch or mechanical / thermal processing during fabrication, welding / joining, and sintering. For example, the heat generated when metal is welded may cause localized expansion of the metal, and when the weldment cools, these areas in the weldment cool and contract more than other areas, creating residual stresses. The existence of residual stress will affect the dimensional stability of material components, and it has an important impact on the safety of structures and the service life of engineering components. In addition, the existence of residual stress is unpredictable, so...

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Problems solved by technology

[0006] In order to overcome the problems of the narrow operating space on the white light interferometry instrument and the need for multiple sets of biaxial residual stress tests in different situations during the experiment, the present invention proposes a biaxial residual stress introduction device based on white light interferometry surface topography , can controllably apply any biaxial residual stress, and can use the white light interferometry instrument to observe the surface topography in situ under the premise of keeping the residual stress unloaded after the indentation is pressed in and unloaded, which overcomes the narrow operating space of the white light interferometry instrument , the problem of not being able to place larger observation objects

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