Modeling and Simulation

Explosive Effects, Ground Shock, and Structure Vulnerability to Weapons: Using the finite element method, we model explosive source experiments. Our modeling uses an “end-to-end” framework, which includes explicit simulation of the source, propagation of shock through the near field geologic medium, and connection through seismic wave fields to the monitoring regime. Modeling allows both parametric studies and comparison to test data, to discern the complex components of explosive source phenomenology and response of engineered systems to loading. This work supports explosion monitoring, weapon targeting, and facility design.

Combined Fluid-Mechanical Fracture: We apply the finite element and hybrid finite-discrete element methods to study rock fractures. This research includes fractures due to explosives and subsequent gas flow through transient permeability, as well as well-bore fracture and reservoir exploitation via hydraulic fracturing for enhanced and oil and gas recovery.

Constitutive Model Development: Developing new and unique material models for use in numerical simulation of geodynamic phenomena. Improved comprehensive material models:

• Enhance description of wave propagation through pre-damaged or weathered media.
• Required to model accurate deformation of Earth materials, particularly at high strain-rates.

Multi-Scale Computational Geomechanics and Geodynamics: Our analysis methods apply to a full variety of scales from micro- to meso- to macro-scale; that is, from microfractures as identified on thin sections, through laboratory rock core analysis, to full field testing of large-yield explosives, including simulations hypothetical nuclear events.

Constitutive Model Development: Much of the work described above is supported by in-house development of appropriate geomaterial models. Constitutive response of rocks and soils is very complex, particularly under dynamic loading. Moreover, recent developments of hybrid finite/discrete elements as well as fully coupled Eulerian and Lagrangian modeling of near source rock regimes requires development of state-of the-art material models to adequately represent the physics of near-source damage.

LANL Profile Google Scholar Esteban Rougier - Team Leader Finite element method Discrete element method Fracture mechanics High strain rate process Hydrofracture

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Chris Bradley - Research Scientist

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Ting Chen - Research Scientist Seismic imaging Earthquake rupture dynamics Reservoir characterization and monitoring Induced earthquakes Microseismicity

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Andrew Delorey - Research Scientist Seismic tomography Seismic surface waves Earthquake simulations Seismic noise analysis Microseismicity detection Seismic hazards Probabilistic seismic hazard analysis

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Earl Knight - Research Scientist

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Carene Larmat - Research Scientist Computational Seismology - normal modes summation, spectral element method, high performance computing, coupled code Seismology - Explosion seismology, Time Reversal of seismic sources, glacial earthquakes, tremor, atmosphere response, planetary seismology Non-Linear Seismology/Acoustics - Time Reversal in laboratory, numerical modeling of non-linear wave propagation

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Zhou Lei - Research Scientist Combined finite-discrete element methods Computational mechanics of discontinua Fracking, contact and impact

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Bryan Euser - Postdoctoral Researcher

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Ke Gao - Postdoctoral Researcher Rock mechanics Earthquake mechanics Geophysics Granular physics

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Viet Tuan Chau - Postdoctoral Researcher Solid mechanics Fracture mechanics Geomechanics Fluid dynamics Finite element analysis