Acoustic emission source locating method and system used for rock mechanics triaxial test

Abstract

The invention discloses an acoustic emission source locating method and system used for a rock mechanics triaxial test. A reflection effect of acoustic emission in an interface of a triaxial loading oil cylinder and an internal sample is considered, a path equation of acoustic wave propagation is established according to a Snell's law, the time for sound to be transmitted from an acoustic emissionsource to a sensor is calculated, and by calculating the difference value between an arrival time difference matrix and an arrival time difference matrix which is measured actually, position coordinates of an acoustic source are obtained. A new method is provided for accurately locating acoustic emission of the rock mechanics triaxial test, and the situation is considered that when a test piece is pressurized during the triaxial test, acoustic waves are generated by internal cracks, and the paths of the test piece are changed in different medium contact surfaces. In the meanwhile, the acoustic emission source locating method and system can also be used for other conditions that acoustic emission sensors and the acoustic source are in different mediums, and the mediums are hook-face mediums.

Description

technical field [0001] The invention relates to a method and a system for locating an acoustic emission source in consideration of the refraction of sound waves at the interface between a test piece and an oil cylinder for rock mechanics triaxial tests. Background technique [0002] The triaxial test of rock mechanics is an important experimental method to obtain the mechanical properties and parameters of rock under high pressure. Because the rock sample is sealed in the triaxial pressurized cylinder, the fracture process and fracture information of the sample cannot be accurately obtained and determined. Acoustic emission testing technology can monitor the location of cracks in rocks and other materials during the loading process, and provide an effective means for studying rock fractures. However, the existing acoustic emission source location method is mainly used for the location of sound sources in a single medium. Assuming that the medium where the sound source is lo...

AI Technical Summary

Problems solved by technology

[0003] In the prior art, CN105842343A discloses an acoustic emission test device with an acoustic emission sensor built into a true triaxial chamber. Although an effective method is provided for the acquisition of acoustic emission signals in a true triaxial test, its Very limited, only suitable for fixed rock size, and cannot be used for routine triaxial tests

Moreover, it is complicated to build the acoustic emission sensor into the true triaxial chamber, which also has an adverse effect on the triaxial loading effect.

CN106442743A discloses an acoustic emission source localization algorithm considering the refraction of sound waves at the interface of two media. Although the refraction occurs when the sound waves encounter different media during the propagation process, it does not consider the case where the media layer is a curved surface. There is also no localization algorithm for refraction on curved media

Images