Title: Phase-field Modeling of Geologic Fractures

Abstract: Geologic fractures such as joints and faults are common in subsurface systems, and their mechanical behavior plays a critical role in many problems related to civil infrastructure, energy, and the environment. As such, a wide variety of approaches have been developed for the simulation of the mechanical behavior of geologic fractures. Yet none of them lends itself to a nearly effortless utilization with the standard finite element method in computational mechanics. Over the past decade, phase-field modeling has become a popular method for numerical simulation of fracture, because it can be easily implemented with the standard finite element method without any surface-tracking algorithms. However, the existing phase-field formulations do not incorporate several critical features of geologic fractures, including frictional contact, pressure-dependence, quasi-brittleness, mode-mixity, roughness, and their combined impacts on cracking. This talk will introduce a class of novel phase-field formulations that incorporate these features in a well-verified and validated manner. Remarkably, these phase-field approaches allow one to simulate the combination of cohesive tensile fracture and frictional shear fracture without any algorithms for surface tracking and contact constraints. It will also be demonstrated how phase-field simulations enable us to gain insight into the failure behavior of rock masses that are challenging to investigate experimentally.

Bio: Jinhyun Choo is an Assistant Professor in the Department of Civil and Environmental Engineering at KAIST. As a civil engineer specializing in geomechanics and computational mechanics, he researches next-generation methods to understand, predict, and control the behavior of complex subsurface systems as they relate to challenges toward safeguarding and decarbonizing the built environment. Born and raised in South Korea, Choo obtained his B.S. and M.S. from Seoul National University and worked at the Korea Institute of Civil Engineering and Building Technology. Later, as a Fulbright Scholar, he received his Ph.D. from Stanford University and conducted postdoctoral research at Columbia University. Prior to joining KAIST in 2022, he was a faculty at The University of Hong Kong. He currently serves as a member of four technical committees of ASCE and four technical committees of ISSMGE.

Zoom Information:

https://oist.zoom.us/j/99438861311?pwd=cHhuNG1HQ2JLUitwTytodDVmVjBuZz09

Meeting ID: 994 3886 1311

Passcode: 385193