Online material biaxial static-dynamic performance test platform under service temperature

Abstract

The invention relates to an online material biaxial static-dynamic performance test platform under service temperature, belonging to the field of precision drive. The large-stroke biaxial synchronous identical-speed or synchronous different-speed displacement output is realized by virtue of four groups of piezoelectric actuators which are orthogonally distributed, and the biaxial static tensile test or dynamic fatigue test for a block-shaped material or a film material with a characteristic size being in a millimeter scale can be carried out under a high / low temperature service condition by combining with an embedded high temperature electrothermal alloy sheet / parr patch. The online material biaxial static-dynamic performance test platform is likely to use in conjunction with a scanning electron microscope with a relatively-large vacuum cavity or other microimaging device with an open-type carrier space, such as an optical microscope, an atomic power microscope and a high speed camera, so that the multimode biaxial static tensile test or the large-frequency-range biaxial dynamic fatigue test can be carried out, and the research for the microstructure evolution behavior and fatigue failure mechanism of various structural materials or functional materials under a complicated service condition such as a high / low temperature condition and a static-dynamic plane stress condition can be facilitated.

Description

technical field [0001] The invention relates to the field of precision driving and the field of in-situ mechanical testing of material fatigue performance, in particular to an online testing platform for biaxial static and dynamic performance of materials at service temperature. Compatible with imaging equipment such as scanning electron microscopes, X-ray diffractometers and optical microscopes, this platform can study the fatigue failure mechanism of materials in high / low temperature service environments and plane stress states, in order to understand and reveal the fatigue of materials In-service reliability and stability of damage and upgrade engineering structures provide testing methods. Background technique [0002] When materials and their products are subjected to alternating loads, although the magnitude of the load they are subjected to is much lower than their yield strength or tensile strength, after repeated and long-term deformation accumulation, the final beh...

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Problems solved by technology

However, since the output displacement of piezoelectric devices is mostly at the level of tens of microns, it is difficult to achieve large-stroke reciprocating motion loading on bulk materials, and the flexible hinge mechanism with large stiffness in piezoelectric actuators often weakens the output displacement of piezoelectric devices. It is difficult for a flexible hinge with small stiffness to achieve a fast response at a higher loading frequency due to its inertial force

[0006] To sum up, up to now, research on in-situ fatigue testing at home and abroad can be classified into three categories: one is the low-cycle fatigue testing with lower frequency loading realized by using in-situ tensile testing equipment under the scanning electron microscope; the other is the scanning electron microscope. The large-stroke fatigue test of bulk materials is realized by using hydraulic drive technology under the electron microscope, but its loading frequency is limited, and it is difficult to adjust the imaging area; the third is the high-frequency fatigue test of micro-scale components based on piezoelectric drive technology under CCD

Due to the large structure, insufficient local frequency, mechanical inertia, and insufficient magnification, the above methods limit the in-depth study of the fatigue damage mechanism under the scanning electron microscope, and the above methods rarely involve fatigue under the plane stress state of the temperature service environment. test device

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