Phoebus Rosakis, Ares J. Rosakis, G. Ravichandran, J. Hodowany,
The energy balance equation for elastoplastic solids includes heat source terms that govern the conversion of some of the plastic work into heat. The remainder contributes to the stored energy of cold work due to the creation of crystal defects. This paper is concerned with the fraction β of the rate of plastic work converted into heating. We examine the status of the common assumption that β is a constant with regard to the thermodynamic foundations of thermoplasticity and experiments. A general ...
Tópico(s): Microstructure and mechanical properties
2000 - Elsevier BV | Journal of the Mechanics and Physics of Solids
Phoebus Rosakis, Ares J. Rosakis,
Tópico(s): Composite Material Mechanics
1988 - Springer Science+Business Media | Journal of Elasticity
Xiaomin Deng, Ares J. Rosakis,
... factor and the crack propagation speed. These relations are found to agree well with experimental measurements by Rosakis et al. (J. Mech. Phys. Solids 32, 443, 1984) and by ...
Tópico(s): High-Velocity Impact and Material Behavior
1991 - Elsevier BV | Journal of the Mechanics and Physics of Solids
Cheng Liu, Ares J. Rosakis, L. B. Freund,
... J. Mech. Phys. Solids40(3), 699–719) and Rosakis et al. (1991, Int. J. Fract. 50, R39–R45), in which dynamic transient effects were included in the near-tip deformation field, the exact mapping equations of caustics are derived for non-uniformly propagating cracks. The resulting ...
Tópico(s): Optical measurement and interference techniques
1993 - Elsevier BV | International Journal of Solids and Structures
Xue Feng, Yonggang Huang, Ares J. Rosakis,
... strictly restricted to stress and curvature states which are assumed to remain uniform over the entire film/substrate system. Recently Huang, Rosakis, and co-workers [Acta Mech. Sinica, 21, pp. 362–370 (2005); J. Mech. Phys. Solids, 53, 2483–2500 (2005); Thin ...
Tópico(s): Metal and Thin Film Mechanics
2007 - ASM International | Journal of Applied Mechanics
M. Mello, Harish S. Bhat, Ares J. Rosakis, Hiroo Kanamori,
The near field ground motion signatures associated with sub-Rayleigh and supershear ruptures are investigated using the laboratory earthquake experiment originally developed by Rosakis and coworkers (Xia et al., 2004, 2005a; Lu et al., 2007; Rosakis et al., 2007). Heterodyne laser interferometers enable continuous, high bandwidth measurements of fault-normal (FN) and fault-parallel (FP) particle velocity "ground motion" records at discrete locations on the surface of a Homalite test specimen as a sub- ...
Tópico(s): Seismic Performance and Analysis
2010 - Elsevier BV | Tectonophysics
Mohamed Abdelmeguid, Chunhui Zhao, Eşref Yalçınkaya, George Gazetas, Ahmed Elbanna, Ares J. Rosakis,
Abstract The 2023 M7.8 Kahramanmaraş/Pazarcik earthquake was larger and more destructive than what had been expected. Here we analyzed nearfield seismic records and developed a dynamic rupture model that reconciles different currently conflicting inversion results and reveals spatially non-uniform propagation speeds in this earthquake, with predominantly supershear speeds observed along the Narli fault and at the southwest (SW) end of the East Anatolian Fault (EAF). The model highlights the critical ...
Tópico(s): Earthquake Detection and Analysis
2023 - Nature Portfolio | Communications Earth & Environment
V. Rubino, N. Lapusta, Ares J. Rosakis,
Tópico(s): Geological and Geochemical Analysis
2022 - Nature Portfolio | Nature
Ahmed Elbanna, Mohamed Abdelmeguid, Xiao Ma, Faisal Amlani, Harsha S. Bhat, Costas E. Synolakis, Ares J. Rosakis,
Tsunami generation from earthquake-induced seafloor deformations has long been recognized as a major hazard to coastal areas. Strike-slip faulting has generally been considered insufficient for triggering large tsunamis, except through the generation of submarine landslides. Herein, we demonstrate that ground motions due to strike-slip earthquakes can contribute to the generation of large tsunamis (>1 m), under rather generic conditions. To this end, we developed a computational framework that integrates ...
Tópico(s): High-pressure geophysics and materials
2021 - National Academy of Sciences | Proceedings of the National Academy of Sciences
Marcello Gori, V. Rubino, Ares J. Rosakis, N. Lapusta,
Significance Fluids present in the Earth’s crust promote earthquakes, as well as a variety of aseismic slip events, both in natural tectonic settings and potentially due to industrial activities, such as wastewater disposal, geothermal energy production, and CO 2 storage. To study the physical processes linking fluids and slip motion, we have devised a laboratory earthquake setup capable of injecting fluid onto a simulated fault and monitoring the resulting slip on a wide range of temporal and spatial ...
Tópico(s): Earthquake Detection and Analysis
2021 - National Academy of Sciences | Proceedings of the National Academy of Sciences
Yuval Tal, V. Rubino, Ares J. Rosakis, N. Lapusta,
Significance Our study explores a major challenge in earthquake science—the dynamics of thrust earthquake ruptures as they interact with the Earth’s surface, which is relevant to some of the most destructive earthquakes that have ever occurred. The work illustrates key features of the complex dynamic behavior associated with this interaction using an ultrahigh-speed imaging technique. The interaction leads to large and rapid reductions in normal stress. However, the frictional shear resistance does ...
Tópico(s): Seismology and Earthquake Studies
2020 - National Academy of Sciences | Proceedings of the National Academy of Sciences
V. Rubino, Ares J. Rosakis, N. Lapusta,
Abstract Many earthquakes propagate at sub‐Rayleigh speeds. Earthquakes propagating at supershear speeds, though less common, are by far more destructive. Hence, it is important to quantify the motion characteristics associated with both types of earthquake ruptures. Here we report on the spatiotemporal properties of dynamic ruptures measured in our laboratory experiments using the dynamic digital image correlation technique. Earthquakes are mimicked by the frictional rupture propagating along the ...
Tópico(s): High-pressure geophysics and materials
2020 - Wiley | Journal of Geophysical Research Solid Earth
Ares J. Rosakis, V. Rubino, N. Lapusta,
Abstract The last few decades have seen great achievements in dynamic fracture mechanics. Yet, it was not possible to experimentally quantify the full-field behavior of dynamic fractures, until very recently. Here, we review our recent work on the full-field quantification of the temporal evolution of dynamic shear ruptures. Our newly developed approach based on digital image correlation combined with ultrahigh-speed photography has revolutionized the capabilities of measuring highly transient phenomena ...
Tópico(s): Rock Mechanics and Modeling
2019 - ASM International | Journal of Applied Mechanics
V. Rubino, Ares J. Rosakis, N. Lapusta,
Producing dynamic ruptures in the laboratory allows us to study fundamental characteristics of interface dynamics. Our laboratory earthquake experimental setup has been successfully used to reproduce a number of dynamic rupture phenomena, including supershear transition, bimaterial effect, and pulse-like rupture propagation. However, previous diagnostics, based on photoelasticity and laser velocimeters, were not able to quantify the full-field behavior of dynamic ruptures and, as a consequence, ...
Tópico(s): earthquake and tectonic studies
2019 - Springer Nature | Experimental Mechanics
V. Rubino, Ares J. Rosakis, N. Lapusta,
Abstract Friction plays a key role in how ruptures unzip faults in the Earth’s crust and release waves that cause destructive shaking. Yet dynamic friction evolution is one of the biggest uncertainties in earthquake science. Here we report on novel measurements of evolving local friction during spontaneously developing mini-earthquakes in the laboratory, enabled by our ultrahigh speed full-field imaging technique. The technique captures the evolution of displacements, velocities and stresses of ...
Tópico(s): Seismology and Earthquake Studies
2017 - Nature Portfolio | Nature Communications
M. Mello, Harsha S. Bhat, Ares J. Rosakis,
Fundamental spatiotemporal field properties and particle velocity waveform signatures of sub-Rayleigh and supershear ruptures were experimentally investigated through a series of laboratory earthquake experiments. We appeal to dynamic rupture theory to extract and highlight previously unnoticed aspects and results, which are of direct relevance to our new experiments. Kinematic relationships derived from both singular and non-singular solutions are applied to analyze and interpret various features ...
Tópico(s): Seismic Performance and Analysis
2016 - Elsevier BV | Journal of the Mechanics and Physics of Solids
V. Rubino, N. Lapusta, Ares J. Rosakis, S. Leprince, Jean‐Philippe Avouac,
Tópico(s): Image and Object Detection Techniques
2014 - Springer Nature | Experimental Mechanics
J. D. Tandy, Jonathan Mihaly, Marc A. Adams, Ares J. Rosakis,
The temporal evolution of a previously observed hypervelocity impact-induced vapor cloud [Mihaly et al., Int. J. Impact Eng. 62, 13 (2013)] was measured by simultaneously recording several full-field, near-IR images of the resulting emission using an OMA-V high-speed camera. A two-stage light-gas gun was used to accelerate 5 mg Nylon 6/6 right-cylinders to speeds between 5 km/s and 7 km/s to impact 1.5 mm thick 6061-T6 aluminum target plates. Complementary laser-side-lighting [Mihaly et al., Int. J. ...
Tópico(s): Energetic Materials and Combustion
2014 - American Institute of Physics | Journal of Applied Physics
M. Mello, Harish S. Bhat, Ares J. Rosakis, Hiroo Kanamori,
A notable feature of the 2002 Mw7.9 Denali, Alaska, earthquake was that a unique set of near-field seismic ground motion records, at Pump Station 10 (PS10), captured the passage of a supershear rupture followed by what was surmised to be a secondary slip pulse, 'Trailing Rayleigh Pulse' (Dunham and Archuleta, 2004, Mello et al., 2010). Motivated by the unique features contained in these near-field ground motion records, which were obtained only 3km away from the fault, a series of scaled laboratory ...
Tópico(s): earthquake and tectonic studies
2013 - Elsevier BV | Earth and Planetary Science Letters
Vahe Gabuchian, Ares J. Rosakis, N. Lapusta, D. D. Oglesby,
Thrust fault earthquakes are studied in a laboratory earthquake setup previously used to investigate analog strike-slip seismic events. Dynamic mode II ruptures are generated along preexisting faults in an analog material, Homalite H-100, and their interaction with the free surface is studied for both sub-Rayleigh and supershear rupture speeds. High-speed digital photography and laser velocimeter diagnostics are used synergistically to identify and study the ground velocity signatures caused by ...
Tópico(s): Seismic Performance and Analysis
2013 - Wiley | Journal of Geophysical Research Solid Earth
Bo Li, Luigi E. Perotti, Marc A. Adams, Jonathan Mihaly, Ares J. Rosakis, Mark A. Stalzer, M. Ortíz,
Large scale three-dimensional numerical simulations of hypervelocity impact of Aluminum alloy 6061-T6 plates by Nylon 6/6 cylindrical projectile have been performed using the Optimal Transportation Meshfree (OTM) method of Li et al. [7] along with the seizing contact and variational material point failure algorithm [17], [18]. The dynamic response of the Al6061-T6 plate including phase transition in the high strain rate, high pressure and high temperature regime expected in our numerical analysis is ...
Tópico(s): Numerical methods in engineering
2013 - Elsevier BV | Procedia Engineering
Harsha S. Bhat, Ares J. Rosakis, C. G. Sammis,
The micromechanical damage mechanics formulated by Ashby and Sammis, 1990, “The Damage Mechanics of Brittle Solids in Compression,” Pure Appl. Geophys., 133(3), pp. 489–521, and generalized by Deshpande and Evans 2008, “Inelastic Deformation and Energy Dissipation in Ceramics: A Mechanism-Based Constitutive Model,” J. Mech. Phys. Solids, 56(10), pp. 3077–3100. has been extended to allow for a more generalized stress state and to incorporate an experimentally motivated new crack growth (damage evolution) ...
Tópico(s): Mineral Processing and Grinding
2012 - ASM International | Journal of Applied Mechanics
Harish S. Bhat, C. G. Sammis, Ares J. Rosakis,
The micromechanical damage mechanics formulated by Ashby and Sammis (Pure Appl Geophys 133(3) 489–521, 1990) has been shown to give an adequate description of the triaxial failure surface for a wide variety of rocks at low confining pressure. However, it does not produce the large negative curvature in the failure surface observed in Westerly granite at high confining pressure. We show that this discrepancy between theory and data is not caused by the two most basic simplifying assumptions in the ...
Tópico(s): High-pressure geophysics and materials
2011 - Birkhäuser | Pure and Applied Geophysics
Marc A. Adams, Ali Lashgari, Bo Li, Michael McKerns, Jonathan Mihaly, M. Ortíz, Houman Owhadi, Ares J. Rosakis, Mark A. Stalzer, Timothy Sullivan,
This Part II of this series is concerned with establishing the feasibility of an extended data-on-demand (XDoD) uncertainty quantification (UQ) protocol based on concentration-of-measure inequalities and martingale theory. Specific aims are to establish the feasibility of the protocol and its basic properties, including the tightness of the predictions afforded by the protocol. The assessment is based on an application to terminal ballistics and a specific system configuration consisting of 6061-T6 ...
Tópico(s): Engineering and Material Science Research
2011 - Elsevier BV | Journal of the Mechanics and Physics of Solids
Duc Ngo, Yonggang Huang, Ares J. Rosakis, W. A. Griffith, David D. Pollard,
We examine the local nature of the dynamic stress field in the vicinity of the tip of a semi‐infinite sub‐Rayleigh (slower than the Rayleigh wave speed, c R ) mode II crack with a velocity‐weakening cohesive zone. We constrain the model using results from dynamic photoelastic experiments, in which shear ruptures were nucleated spontaneously in Homalite‐100 plates along a bonded, precut, and inclined interface subject to a far‐field uniaxial prestress. During the experiments, tensile cracks grew periodically ...
Tópico(s): High-pressure geophysics and materials
2011 - American Geophysical Union | Journal of Geophysical Research Atmospheres
Veronica Eliasson, M. Mello, Ares J. Rosakis, Paul E. Dimotakis,
Tópico(s): Combustion and Detonation Processes
2010 - Springer Science+Business Media | Shock Waves
Ronald L. Biegel, Harish S. Bhat, C. G. Sammis, Ares J. Rosakis,
Tópico(s): High-pressure geophysics and materials
2010 - Elsevier BV | Tectonophysics
Harish S. Bhat, Ronald L. Biegel, Ares J. Rosakis, C. G. Sammis,
We investigate asymmetric rupture propagation on an interface that combines a bulk elastic mismatch with a contrast in off-fault damage. Mode II ruptures propagating on the interface between thermally shocked (damaged) Homalite and polycarbonate plates were studied using high-speed photographs of the photoelastic fringes. The anelastic asymmetry introduced by damage is defined by 'T' and 'C' directions depending on whether the tensile or compressive lobe of the rupture tip stress concentration lies ...
Tópico(s): Rock Mechanics and Modeling
2010 - Elsevier BV | Tectonophysics
Xue Feng, Yonggang Huang, Ares J. Rosakis,
Tópico(s): Adhesion, Friction, and Surface Interactions
2007 - Elsevier BV | International Journal of Solids and Structures
Irene Arias, Jaroslaw Knap, Vijaya Chalivendra, Soonsung Hong, M. Ortíz, Ares J. Rosakis,
The conceptual simplicity and the ability of cohesive finite element models to describe complex fracture phenomena makes them often the approach of choice to study dynamic fracture. These models have proven to reproduce some experimental features, but to this point, no systematic study has validated their predictive ability; the difficulty in producing a sufficiently complete experimental record, and the intensive computational requirements needed to obtain converged simulations are possible causes. ...
Tópico(s): Fluid Dynamics Simulations and Interactions
2007 - Elsevier BV | Computer Methods in Applied Mechanics and Engineering