High temperature fracture parameter test method and its device

Abstract

The invention discloses a high-temperature fracture parameter test device, which comprises a loading mechanism, a high-temperature heating furnace arranged inside the loading mechanism, a CCD camera, a data acquisition card and an electronic computer. The invention also discloses a high-temperature fracture parameter test method based on the device. The high-temperature fracture parameter test method and the device of the invention can realize the measurement under the condition of high temperature measurement, the precision is high, which can reach the micron level, and can realize the long-time measurement and accurate calculation of the fracture parameter measurement, and thereby providing basic data for the safety design, as well as the quantitative life assessment of the mechanical structure.

Description

technical field [0001] The invention belongs to the intersecting fields of mechanical engineering, materials, mechanics and experimental technology, and specifically relates to a high-temperature fracture parameter testing method and a device thereof. Background technique [0002] The development of advanced fracture mechanics has made it possible to assess the reliability and safety of mechanical structures. To carry out structural fracture prevention design and life assessment under high temperature environment, mastering the growth law of high temperature creep crack is a necessary condition, and it is inseparable from the accurate measurement of high temperature fission growth, so it is very necessary to carry out metal high temperature creep crack growth test. [0003] There are many methods for measuring crack growth, such as the early traditional method of using a microscope to visually measure the crack length, the method for automatically measuring surface crack gro...

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Problems solved by technology

Although the flexibility method based on the flexibility theory can be used for the measurement of creep crack length at higher temperatures, its accuracy is not ideal, and it is limited in high temperature crack measurement because the extensometer is not easy to use at high temperatures

[0004] At present, there are mainly two methods available for high temperature fission testing: the first method is the potential method, which mainly uses a constant current applied at both ends of the sample to obtain the crack growth length indirectly by measuring the potential difference between the two ends of the crack surface; The disadvantage of the method is that the accuracy of the results is limited by the instrument, and there are many influencing factors, and the dispersion of the data results is large.

The second method is the extensometer method, which is used to measure the growth rate of metal creep cracking. It is necessary to extend the extensometer to the grooves at the upper and lower ends of the loading line at the opening of the sample to obtain the displacement of the loading line of the sample, and then To determine the crack growth length of metal materials, the accuracy is high, and its disadvantage is that the requirements for the extensometer are high, and the price is expensive, so it is difficult to be widely used

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