EQdyna (3D)

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1. History

      EQdyna (Duan and Oglesby, 2006; Duan and Day, 2008; Duan, 2010, 2012) is an explicit and parallel dynamic finite element method (FEM) code developed for earthquake dynamic rupture and seismic wave propagation simulations. Both 2D and 3D versions of EQdyna have been verified against benchmark problems of the SCEC/USGS Spontaneous Rupture Code Verification Project (Harris et al., 2009, 2011, 2018). EQdyna features an underintegrated hexahedron element (Hughes, 2000) stabilized by hourglass control (Kosloff and Frazier, 1978). With the explicit central difference time integration, EQdyna is highly efficient and accurate in simulating spontaneous rupture and seismic-wave propagation. The traction-at-split-node scheme of Day et al. (2005) is adopted to treat the faulting boundary. Perfectly Matched Layer (PML) absorbing boundary (e.g., Collino and Tsogka, 2001; Ma and Liu, 2006) is implemented to reduce model sizes for computational efficiency (Liu and Duan, 2018). The coarse grained Q model (e.g., Day, 1998; Ma and Liu, 2006) is incorporated to model the freqeuncy-related anelastic attenuation of seismic waves (Liu and Duan, 2018). Various friction laws such as slip-weakening, rate- and state- friction that govern earthquake proceses are implemented (Luo and Duan, 2018). 

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2. General features of the FEM and parallelization

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3. Code structure

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4. Specific features

      4.1 How to model earthquake faults: split-nodes 

      4.2 Drucker-Prager plasticity 

      4.3 Perfectly Matched Layer

      4.4 Coarse-grained Q model

      4.5 Friction laws

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5. Versions and benchmark problems

   

 

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