XRCT Hydromechanical Damage Evolution In Porous Rocks: Characterisation and Modelling

Project description

Damage evolution in rocks is of particular importance in several engineering disciplines such as civil, mining, and petroleum. While the mechanical damage characterisation and modelling in rock mechanics goes back to several decades ago, the effect of pore pressure on damage evolution under mechanical loading is still not yet fully understood. This is partly due to experimental difficulties in monitoring the hydro-mechanical damage precisely. The advancement of X-ray computed tomography has now enabled tracking the damage evolution in rock at high resolution providing a strong tool for rock damage characterisation.

The XRCT tool can be used with ultrasonic monitoring to further enable detailed characterisation of damage parameters. In this proposal therefore the newly developed ultrasonic enabled X-ray transparent triaxial system will be used to characterise the porous rock damage under different coupled stress and pore pressure conditions. This system uses a patented triaxial cell to perform triaxial testing on rock materials while enabling the measurement of ultrasonic and X-ray imaging at elevated pore pressure and temperature. The understating from the obtained experimental data will be used to develop a new damage evolution model based on the damage mechanics and non-equilibrium thermodynamics principles. This theoretical model combination will enable capturing the main physical processes in the system thus increasing the confident in the performance of the developed model. Finally, the developed model, will be validated with the obtained experimental data and its detailed performance will be tested through a simple numerical exercise coded in COMSOL/Abaqus.

Outcomes

The proposed project consists of the following overlapping stages:

• Mechanical damage characterisation using combined XRCT and ultrasonic imaging.
• Coupling the hydraulic damage with mechanical damage and characterised the evolution of damage using combined XRCT and ultrasonic imaging.
• Develop a damage model using entropy production principles (irreversible thermodynamics) and damage mechanics.
• Validate the developed model with the obtained experimental data.

Essential capabilities

Knowledge of Geotechnical and/or Structural and/or Mechanical Engineering with academic achievement.

Desireable capabilities

Experience in experimental testing, thermodynamics and damage mechanics. In case the student does not have the relevant experience, the student will be encouraged to undertake additional studies in this field at UQ and/or IIT Delhi.

Expected qualifications (Course/Degrees etc.)

Master’s Degree in Geotechnical, Civil, Petroleum or Mining Engineering or a related discipline.

Candidate Discipline

XRCT ultrasonic imaging Damage evolution Hydromechanical.