| Exploring the dynamic monitoring method of rock deformation and temperature in liquid nitrogen ultra-low temperature environment(-196 °C)is of great significance for the study of rock mechanical properties under liquid nitrogen fracturing and ultra-low temperature environment.Rocks have different characteristics in the deformation process due to their composition,porosity and micro-framework under ultra-low temperature conditions.There is no mature test method for the dynamic monitoring of rock deformation and temperature data in ultra-low temperature environment.In this paper,the fiber grating strain sensor is placed in the rock specimen,and different rock specimens are used in the test process.The different placement method of the sensors and different cooling rate are used to realize the dynamic monitoring of rock specimen deformation and temperature data under ultra-low temperature environment to analyze the data results.The research shows that under the environment of liquid nitrogen ultra-low temperature,different types of rock specimens would have different degrees of shrinkage damage.The deformation of rock specimens has obvious time-phase and spatial locality characteristics.There is certain time difference between the internal temperature variation of rock specimens and the deformation of specimens;the fiber grating sensor can perform dynamic monitoring of rock deformation and temperature data in ultra-low temperature environment. |
