Testing device and testing method for high-temperature fatigue property of microelement under compound stress

Abstract

The invention relates to a testing device and a testing method for high-temperature fatigue property of a microelement under a compound stress and belongs to the field of precise driving. Three built-in encapsulated piezoelectrically stacked multi-load piezoelectric drivers are in an equilateral triangle topological mounting form. The axial elongation movement under different time sequence voltages correspond to stretching-bending compound stressed forms in different modes of the to-be-tested microelement through transmission of motion of a spherical pair and a transmission pair, that is, three-degree-of-freedom high frequency alternating motion of one clamping end of a test piece is realized. The stretching piezoelectric drivers with regular groove structures can preload a uniaxial stretching load with relatively great motion displacement. In addition, a silicon nitride heating piece is embedded into a rectangular slot of a clamp body, so that a service temperature field with a controllable temperature gradient can be constructed. The testing device provided by the invention is compact in structure and rich in test content, and can be used for researching multi-stress fatigue failure behaviors of aero-engine materials and the like under a high-temperature service environment.

Description

technical field [0001] The invention relates to the fields of precision driving and material mechanical performance testing, in particular to a device and method for testing high-temperature fatigue performance of micro-components under composite stress. Through the compatible use with the three-dimensional digital speckle imaging instrument, the present invention can carry out the high-temperature fatigue performance test under the action of tensile-bending composite load, and can conduct research on the multi-stress fatigue failure behavior of aero-engine materials and the like under high-temperature service environments, So as to provide a test method for improving the service reliability of engineering structures. Background technique [0002] When a material or component is subjected to repeated or alternating loads, although the magnitude of the load on the material or component is much smaller than its tensile strength or yield strength, or even smaller than the elast...

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Problems solved by technology

[0004] The purpose of the present invention is to provide a high-temperature fatigue performance test device and method of micro-components under composite stress, which solves the test content that the existing high-temperature fatigue test device only has a single load mode, such as tension-compression mode, three-point bending mode, etc.

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