Speaker: Yumeng Zhao, Ph.D.
When: Wednesday, March 5, 9:00AM – 10:00AM
Where: PKI 250 (Omaha), SEC C107 (Lincoln)
Zoom: https://unl.zoom.us/j/9629884675
Title: Modeling extreme deformation in granular materials: insights to natural hazards and energy
Abstract: Granular materials, such as soils and rocks, often undergo extreme deformations, leading to natural hazards like earthquakes and landslides. Conversely, controlled deformation is key to engineered processes such as subsurface energy extraction and biomass-based energy production. Advanced numerical methods are essential for understanding and managing these behaviors. This presentation explores numerical approaches for mitigating earthquake surface fault rupture hazards and improving biomass energy utilization. The Discrete Element Method (DEM) is used to model fault rupture in both reverse and normal faulting scenarios, with mitigation strategies—such as inserting weak zones or strong walls—evaluated for their effectiveness in protecting infrastructure. Insights from inter-particle force chain development reveal the physics behind these strategies, while cautionary findings highlight scenarios where mitigation efforts may fail or worsen conditions, emphasizing the need for careful implementation. Similar challenges arise in biomass energy production, where poor flowability of granular biomass causes biorefinery downtime. To address this, Smoothed Particle Hydrodynamics (SPH) is employed to model large deformations in biomass materials, incorporating an advanced mechanical model and innovative boundary treatment. The solver, developed for the first time specifically for biomass, accurately captures complex flow behaviors, providing guidance on preventing clogging and jamming during processing. Together, these studies advance our understanding of extreme granular deformation through cutting edge numerical modeling. The insights gained contribute to sustainable geo-energy solutions and improved resilience against natural hazards.