Equi-biaxial residual stress applying device

Abstract

The invention discloses an equi-biaxial residual stress applying device, which comprises an upper clamp (1) having a first press ring (12); and a lower clamp (2) in threaded connection with the upper clamp (1) and with a second press ring (23) coaxially arranged with respect to the first press ring (12), and the first press ring and the second press ring have different diameters. The inventive equi-biaxial residual stress applying device can simultaneously obtain tensile stress and compressive stress in different numerical value ranges, has simple operation and controllable numerical value, and provides necessary conditions for residual stress formula deduction. The device of the invention overcomes the defect that the compressive stress can be obtained only by cutting the sample, and realizes zero destruction. After the equi-biaxial residual stress applying device applies stress to a material, nano-indentation test is carried out and relationship between the indentation parameter and the residual stress can be established to obtain a residual stress calculation model.

Description

technical field [0001] The invention relates to the technical field of testing devices, in particular to an equibiaxial residual stress applying device. Background technique [0002] In recent years, nanoindentation technology has been proposed as an in-situ and nanoscale local mechanical analysis technology, and it has been widely used to measure the hardness, elastic modulus and residual stress of materials. However, the nanoindentation method cannot directly "press" the residual stress value, and it is necessary to find out the relationship between the indentation parameters and the residual stress and finally derive the residual stress formula. When deriving the formula, a large number of different residual stress values ​​are required. [0003] Therefore, how to apply a certain residual stress to the stress-free material, to control the magnitude of the applied stress at will, and to apply compressive stress and tensile stress at the same time, has become an important ...

AI Technical Summary

Problems solved by technology

However, the existing residual stress application device can only obtain compressive stress or tensile stress separately, and the application device of compressive stress cannot control the magnitude of the applied stress, and the compressive stress can only be obtained by cutting and destroying the sample.

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