Modelling failure propagation using the phase-field method with the assistance of ultrasonic wave velocity measurement

The phase-field method in damage mechanics is attracting increasing popularity in rock engineering, which bridges the gap between microcracking fracture mechanics and quantified damage mechanics. The quasi-static microcrack propagation can be well captured in FEM via the phase-field damage method. However, the determination and calibration of the length scale parameter (l) in the phase-field method are still unclear since the influence width of microcracks cannot be directly observed. In this research, the phase-field damage method is applied to simulate rock behavior under triaxial tests. The length scale parameter is calibrated via ultrasonic wave velocity measurements. The results show that the phase-field damage can be calibrated via ultrasonic wave velocity measurement, which empowers the application of phase-field damage in engineering applications.