Yushan Song: Influence of Mesh Topology and Model Parameters on Glacier Fracture and Stability in Three-Dimensional HFDEM Simulations
Accurately simulating glacier calving requires models that can capture the fracture initiation and propagation. This project further develops a three-dimensional hybrid finite–discrete element method (HFDEM3D) to investigate glacier fracture, calving and stability under ocean forcing. By representing intact ice with finite elements and explicitly simulating fractures along element interfaces, HFDEM3D captures detailed fracture evolution and calving processes that are often simplified or parameterised in conventional glaciological models. However, predictions may be sensitive to mesh topology and input parameters. This study implements a simplified hydro-mechanical model into HFDEM3D to simulate fracture and calving of an idealised marine-terminating glacier. A strength-reduction method calculates the factor of safety (FoS) to quantify glacier stability. Simulations using structured and unstructured tetrahedral meshes with comparable mesh densities are compared in terms of stress redistribution, fracture-initiation location, crack-propagation pathway, dominant failure mode, calving pattern and FoS. Preliminary results show broadly similar fracture and calving behaviour between the two mesh configurations. However, the unstructured mesh produces a higher FoS than the structured mesh. This difference may arise from the irregular orientations and spatial distribution of elements in the unstructured mesh, which influence local stress transfer. A parameter sweep is being performed to assess the effects of variations in elastic properties, density, interface strengths, fracture energies and the friction coefficient. By distinguishing topology-induced variability from parameter-related variability, this study provides glacier and cryospheric modellers with a basis for evaluating the reliability of HFDEM predictions of fracture and calving.