Tim Lewis, John Baumgardner 0 500 1000 1500 0.00 0.02 0.04 0.06 0.08 0.10 Stress (MPa) Strain Stress-Strain Curves[3] Temp (K) 500 Temp (K) 1123 Temp (K) 1223 Temp (K) 1333 Material: Lherzolite* ◦Density: ◦Bulk Modulus: ◦Coefficient of Thermal Expansion: Time (s) (m/s) 0 – 100 0 100 – 1100 1.6 (ramped) 1100 – 20,000 1.6 (constant) Abstract Within the framework of catastrophic plate tectonics, large tsunamis are a plausible mechanism for producing fossil-bearing sediments of the Flood rock record. The focus of this research is to model the behavior of an overriding slab in contact with a rapidly subducting plate with the aim of understanding in more detail the tsunami generation process. Key to this process is the locking and unlocking of the overriding and subducting slabs. The unlocking results in the rapid rise of the sea bottom and generation of a tsunami. Several key questions arise in this context that our study seeks to answer. What is the relationship between the coefficient of friction and the slip rate that allows the plates to be locked sufficiently long to produce large tsunamis? What sort of the stresses occur to keep the slabs locked together? How rapidly can the deformed overriding slab relax mechanically from its deformed shape? How much deformational heating arises when the overriding slab is repetitively loaded? To address these questions in a quantitative manner, we apply the finite element analysis code Ansys. Preliminary results show the relaxation time is short enough (~15 min for 2.5 km of deflection of the overriding plate). Additionally, stresses look reasonable for the large deflections that occur. [1] PLANE183. Ansys, Inc. Accessed: 7/22/2022. [Online]. Available: https://ansyshelp.ansys.com/Views/Secured/corp/v222/en/ans_elem/Hlp_E_PLANE183.html. [2] Characteristic Length (LS-DYNA). Ansys, Inc. Accessed: 7/14/2023. [Online]. Available: https://ansyshelp.ansys.com/Views/Secured/corp/v222/en/wb_msh/msh_char_lenlsdyna.html [3] Sherburn, J.A., Horstemeyer, M.F., Bammann, D.J. and Baumgardner, J.R. (2011), Application of the Bammann inelasticity internal state variable constitutive model to geological materials. Geophysical Journal International, 184: 1023-1036. https://doi.org/10.1111/j.1365-246X.2010.04917.x [4] 3.9.5.4. Static and Dynamic Friction Coefficients. Ansys, Inc. Accessed: 7/14/2023. [Online]. Available: https://ansyshelp.ansys.com/account/secured?returnurl=/Views/Secured/corp/v222/en/ans_ctec/Hlp_ctec_realkey. html Element Characteristic Length (km) Characteristic Length[2]: where, is element area is element edge length is the diagonal of quad element PLANE183 Geometry[1] Geometry Layout Mesh Description Material Definition Boundary and Initial Conditions Location Temperature (applied to nodes) Elastic Foundation Stiffness: Preload: Coefficient of Friction[4]: where, (applied to elements) Initial Pressure in Overriding Slab (Mpa) Point A Units: Kilometers Displacement (km) Equivalent Stress (MPa) Equivalent Plastic Strain (km/km) -6 -5 -4 -3 -2 -1 0 0 2 4 6 8 101214161820 Displacement (km) Time (s) Thousands Vertical Displacement of Point A
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