Abstract: A detailed understanding of the thermal and mechanical damage threshold behavior of rocks at elevated temperatures, thermal cyclic loading, and cyclic mechanical loading is a key concern in nuclear waste disposal, underground coal gasification, enhanced geothermal energy, shale gas production, and CO2 sequestration. Thermal properties (thermal conductivity, diffusivity, heat capacity, thermal expansion, and effusivity) can be measured at different thermal cycles, at elevated temperatures from 20°C to 1000°C, and at different saturation rates with different fluid types. The mass variation and endothermic/exothermic mechanism will be measured by thermogravimetric analysis and differential thermal analysis (DTA, TGA, and DSC). Laboratory tests will be conducted to measure ultrasonic velocity, porosity measurements, SEM, X-ray micro-CT scans, and NMR used for fracture morphology and pore characterization of rocks. In this research, true triaxial compression tests with permeability measurement, uniaxial compression tests, and BTS are applied, including ultrasonic data acquisition and acoustic emission (AE) monitoring. The dynamic mechanical test will be conducted on a rock under different strain rates and different impact loadings by using the high-temperature split Hopkinson pressure bar (SHPB) experimental system. The crack initiation, propagation, and coalescence processes were monitored during the deformation using both ultrasonic and acoustic emission (AE) monitoring techniques. Thermomechanical data of tested specimens were incorporated into a (FEM, FDM, FVM, and DEM) element model.

Meeting ID: 944 2649 3601
Passcode: 070134