Non-uniform Slip Research Articles

Seismic response of mountain tunnel induced by fault slip

With the rapid development of Chinese transportation networks, such as the Sichuan-Tibet railway, numerous tunnels are under construction or planned in mountainous regions. Some of these tunnels must traverse or be situated near active fault zones, which could suffer damage from fault slip. In this study, the seismic response of a mountain tunnel subjected to coseismic faulting was analyzed using a fault-structure system in a two-step process. Firstly, a nonuniform slip model was proposed to calculate the ground deformations and internal displacements induced by a specific active fault on a geological scale, considering nonuniform slips on the fault plane. The 1989 Loma Prieta and 2022 Menyuan earthquakes were chosen as case studies to validate the proposed slip model. Secondly, the calculated displacement of the Menyuan earthquake was used as the input load for the discrete–continuous coupling analysis of the Daliang tunnel on an engineering scale. The simulated deformation of the Daliang tunnel aligned with the on-site damage observations following the Menyuan earthquake. Lastly, the effects of different fault conditions on the tunnel seismic response were investigated. The results indicate that the distribution of the peak longitudinal strain of the lining is governed by fault mechanisms, and the degree of fault slip significantly influences the response of the tunnel. A tunnel passing through an active fault with a wider fault fracture zone and smaller dip angle experience less damage.

Unlocking slip-mediated bending in multilayers: Efficient modeling and solutions with high precision and simplicity

This work introduces a novel approach to understanding the bending behavior of multilayer structures with weak interfaces. Despite the existence of various theoretical models, achieving high accuracy and computational efficiency remains a challenge. To address these limitations, we propose a Non-uniform Slip Model (NSM) governed by two essential dimensionless parameters: the number of layers and the shear factor. Utilizing the Semiparametric Hybrid Variational (SHV) method, we derive theoretical solutions that require less computational effort and offer enhanced accuracy. We further simplify the NSM through homogenization to the Uniform Slip Model (USM), yielding clear and concise analytical solutions for deflection curves and effective bending stiffness with high precision. The USM is also extended to account for nonlinear slipping interfaces with continuous shearing flow, providing an analytical stiffness expression that includes the bending angle. This extension explains the experimental observation of multilayered graphene’s bending stiffness, which decreases from cubic to linear with increasing number of layers due to continuous slip and dislocation between atomic layers. Our study delivers theoretical insights for analyzing slip-mediated bending in laminated materials, paving the way for the design and optimization of such structures.

Impact of Variable Fault Geometries and Slip Rates on Earthquake Catalogs From Physics‐Based Simulations of a Normal Fault

AbstractPhysics‐based earthquake simulators have been developed to overcome the relatively short duration and incompleteness of historical earthquake and paleoseismic records, respectively. These simulators have the potential to be a useful addition to seismic hazard assessment as they produce millions of synthetic earthquakes over thousands to millions of years using predefined fault geometries and slip rates. Due to the sparsity of fault data and the computational expense of the modeling, it is common to simplify earthquake simulator input parameters. Fault surfaces are typically characterized by simplified mapped traces and constant dip with depth, with slip rates that are often assumed to be uniform over the fault plane. This study uses the well‐defined 3D geometry of an active normal fault in offshore Aotearoa New Zealand, the Cape Egmont Fault, to demonstrate the impact of using nonuniform slip rates and nonplanar fault geometries on the resulting synthetic earthquakes from the earthquake simulator RSQSim. Adopting variable slip rates that decrease to zero along the fault tipline (rather than uniform slip rates) reduces unrealistically high nucleation rates of seismicity along fault edges. Introduction of complex 3D fault geometries, including fault segmentation and bends on kilometer scales, and variable slip rates produces less characteristic earthquake populations, increasing the number of M6‐7 moderate‐large magnitude events. Incorporation of variable fault geometries and slip rates in physics‐based simulators may modify the seismic hazards estimated from synthetic earthquake catalogs.

Entropy generation in Williamson hybrid nanofluid with inclined magnetic field, non-uniform heat flux, thermal radiation and slip effects

The present study provides the influence of entropy generation on steady two-dimensional laminar non-Newtonian Williamson hybrid nanofluid flow past a horizontal stretching sheet under the influence of the inclined magnetic field, radiation, non-uniform heat source/sink and slip effects. The governing partial differential equations are reduced to a system of ordinary differential equations using similarity transformations. The Runge–Kutta-4rth order method and the shooting technique are then adopted to solve the system. Two different kinds of fluids namely the engine oil based Molybdenum disulfide (MoS 2) nanofluid and Zinc Oxide (ZnO)-Molybdenum disulfide (MoS 2) engine oil hybrid nanofluids are considered to investigate the flow. The effect of important parameters on velocity, temperature, entropy generation and Bejan number are displayed in the form of figures and tables. Our results for some special cases are compared with previously published results to check the present study’s correctness and were found to be in good agreement. It is observed that the Williamson parameter increases the temperature but decreases the entropy generation whereas the angle of inclination of the magnetic field increases both the temperature and entropy generation. It is also observed entropy decreases with an increase in either velocity or thermal slips whereas it increases with radiation.

Interfacial slip verification and slip defect identification in shrink-fitted bimetallic sleeve roll used in hot rolling mill

Shrink-fitted sleeve rolls have several advantages including the ability to reuse shafts by replacing worn sleeves and the ability to apply to next-generation rolls. However, the authors’ previous simulation showed a “non-uniform slip” may appear between the shaft and the shrink-fitted sleeve even under free rolling and when no overall uniform slip condition is satisfied. In this paper, the rolling experiment is conducted by using a miniature rolling mill to verify the slip phenomenon realized by the numerical simulation. To understand the phenomenon, the slip defect formation and the slip growth are investigated by observing the slipped surfaces in detail. It is found that the slip defect starts from the contact of the surface roughness where the width of the defect coincides with the pitch of the machining feed. Eventually, the slip defect is developed by erosion wear and cohesive wear during the rolling and finally forming a large oval-shaped erosion groove at the end of the scratch. Finally, the fatigue strength of the sleeve roll is evaluated by considering the slip defect geometry observed from the experiment.

Stress State in the Source Region of Mw2.2 Earthquake in a Deep Gold Mine in South Africa Determined from Borehole Cores

In December 2007, an Mw2.2 earthquake occurred in a gabbroic dike at 3.3 km depth in a deep gold mine in South Africa. The fore- and aftershock activity was analyzed in an effort to understand the preparation and generation processes of earthquakes; these findings have already been published. The present paper focuses on the stress state in the source region of the mainshock. A 90-m-long borehole across the mainshock fault was drilled ~ 1.5 years after the mainshock and logged by an optical televiewer. The fault can be identified by severe damage to the borehole wall at the point where the borehole intersected the aftershock cluster. Except for a 10-m section in the hanging wall of the fault, borehole cores were fully recovered. Borehole breakout (BO) and core disking (CD) were found to occur. Two stress measurement techniques [Deformation Rate Analysis (DRA) and Diametrical Core Deformation Analysis (DCDA)] were applied to the borehole cores. By combining their results with occurrence criteria for BO and CD, the principal stress state in the source region of the mainshock was determined. The principal directions in the hanging wall of the fault were nearly identical to the virgin stress state, while it was significantly disturbed in the footwall. The vertical stresses were 106 MPa and 40 MPa in the hanging wall and footwall, respectively. The significant difference in the vertical stress between the two sides of the fault can be explained by the stress redistribution associated with a nonuniform slip on a nonplanar fault.

Study on interface non-uniform slip of combined rotor considering real preload distribution

This paper studied the interface non-uniform slip phenomenon and proposed a characterization model. Firstly, by analyzing the mechanical status of combined rotor during operation, the generation mechanism of non-uniform slip is revealed. Then, the bolt preload is tested by ultrasonic testing system, and the non-uniform slip simulation based on measured preload distribution is carried out. Finally, by constructing the Generalized Gray Level Co-occurrence Matrix (GLCM) considering the preload distribution and extracting the corresponding texture features, a non-uniform slip characterization model is established. The paper discussed the influence of rotational speed and various coefficients on the characterization model, when the coefficients selection is reasonable, the model error is 2.11%. The research content strongly supports the study of connection structure dynamics.

Correction to: Regional Tsunami Forecasting: Uncertainties Due to Non-uniform Slip

Correction to: Regional Tsunami Forecasting: Uncertainties Due to Non-uniform Slip

Regional Tsunami Forecasting: Uncertainties Due to Non-uniform Slip

Regional Tsunami Forecasting: Uncertainties Due to Non-uniform Slip

Coupled Faxen relations for non-uniform slip Janus spheres

A non-uniform surface slip can cause a symmetry breaking in the geometry of an otherwise homogeneous spherical particle to give rise to an anisotropic hydrodynamic resistance to the particle. Here, we develop a more general theoretical framework capable of decoding the surface-pattern-dependent hydrodynamic features for single heterogeneous spheres having arbitrary non-uniform slip length distributions in small variations, especially for those of weakly stick–slip or slip–slip Janus spheres in either the two-faced or striped type. Utilizing the Lorentz reciprocal theorem in conjunction with surface spherical harmonic expansion, we derive a new coupled set of Faxen formulas for the hydrodynamic force and torque on a non-uniform slip sphere by expressing impacts of slip anisotropy in terms of surface dipole and quadrupole without solving detailed flow fields. Our results reveal not only how various additional forces/torques arise from surface dipole and quadrupole, but also that it is the anti-symmetric dipole responsible for distinctive force-rotation/torque-translation coupling. These features are very distinct from those of no-slip or uniform-slip particles, possibly spurring new means to characterize or sort Janus particles in microfluidic experiments. In addition, the coupled Faxen relations with surface moment contributions reported here may infer potential changes in the collective nature of hydrodynamic interactions between non-uniform slip spheres. Furthermore, the present framework can also be readily applied to heterogeneous self-propelled squirmers whose swimming velocities are sensitive to slip anisotropy.

The impact of heterogeneous microstructural features on crystal plasticity modeling of plastic anisotropy

Crystal plasticity finite element models typically assume each grain starts with a spatially uniform dislocation distribution, meaning each grain is initialized with a single lattice orientation and all grains share the same slip resistance. This study assessed that assumption by comparing crystal plasticity simulations of tensile tests against experiments on an extruded aluminum 7079 alloy. The simulations utilized computational microstructures with ‘pancaked’ grains and a significant degree of crystallographic texture, consistent with experimental measurements. In one case, the computational microstructures were assigned a single slip resistance and a single lattice orientation for each grain prior to the tension tests. In another case, the extrusion process prior to the tension tests was simulated to cause nonuniform slip resistances, nonuniform crystal orientations within each grain, and nonuniform slip resistances at each material point. Both approaches produced reasonably accurate predictions of the measured yield stress and lateral strain ratio anisotropy, but the predictions considering the initial nonuniformity exhibited less prediction error. Other factors, such as latent vs self hardening of slip systems and fine vs coarse grains, did not have as large an impact. These results suggest that dislocation heterogeneity should be experimentally characterized and fed into future crystal plasticity simulations.

Lattice Boltzmann investigation of the influence of slip distributions on the flow past a diamond cylinder at low-Reynolds-number

Two-dimensional flow past a diamond cylinder with varying slip distributions is numerically investigated using the lattice Boltzmann method at a Reynolds number of 100. Nine slip distributions, namely, fore-up (FU), after-up (AU), fore-up + fore-down (FU–FD), after-up + after-down (AU–AD), FU–AU, FU–AD, FU–FD–AU, FU–AU–AD, and full-slip, are examined and compared with the no-slip case. Fore-side and after-side slip were found to have opposite effects on the friction drag of the diamond cylinder, and the combination of the fore-up and after-up (FU–AU) slip is beneficial for pressure reduction. A maximum drag reduction of 13.6% is achieved by the full-slip case mainly contributed by the pressure reduction. Furthermore, comparison of two typical slip distributions with a non-uniform slip length is investigated. A uniform slip length for the FU and AU (or the FD and AD) is found to be very helpful for pressure reduction. The asymmetric slip distributions could also result in torque on the cylinder, which can be utilized to achieve flow control by adjusting the slip length and the slip length difference between different locations of the cylinder edges.

Non-Newtonian fluid flow having fluid–particle interaction through a porous zone in a channel with permeable walls

Abstract The flow of Casson fluid streaming through a porous zone in a permeable channel with homogeneously distributed dust particles is studied. The flow is oscillatory and exposed to thermal radiation. With non-uniform temperature and velocity slip at the wall, the channel is put under transverse magnetic flux control. The variable separation approach is used to obtain the exact analytic solution for the flow fields of fluid and dust particles. Physical insights of collective effects of suction/injection, magnetic field, thermal radiation, and buoyance force on the fluid velocity, temperature, rate of heat transport and friction at the wall surface are examined and analysed graphically. Results reveal that surface friction increases on both channel plates as an injection on the hot plate rises.

The relationship between slip behavior and dislocation arrangement for large-size Mo-3Nb single crystal at room temperature

The slip behavior and mechanism of large-size Mo-3Nb single crystal have been investigated and disclosed comprehensively at room temperature by quasi-static compression with various strains. With the increase of deformation, the slip traces change from shallow non-uniform slip lines to dense and uniform slip bands. Different slip traces in the same deformation condition were observed, suggesting that the slip traces in the single crystal are controlled by different types and arrangement mechanisms of mobile dislocation. To clarify the relationship between slip behavior and dislocation arrangement, TEM and AFM analyses were performed. Significant discrepancy between the mobility of screw segments and edge segments caused by double cross-slip multiplication mechanism is the reason why different slip features were witnessed. During the whole slip deformation process, screw dislocations play a dominant role and they are inclined to form wall-substructures by interaction and entanglement. With the development of dislocation accumulation, the entangled dislocation walls evolve into dislocation cells with higher stability.

Nonuniform Slip Effect in Wetting Films

The slip effect in wetting films is theoretically studied, and a nonlinear dependence of the hydrodynamic velocity on the slip length is discovered. It is demonstrated that the hydrodynamic flow is essentially affected by the presence of a nonuniform slip length distribution, leading also to enhancement of the energy dissipation in the films. This effect could dramatically slow the usually quick hydrodynamic flows over superhydrophobic surfaces, for instance.

Tsunami inundation hazard across Japan

Japan faces the world's highest tsunami hazard and risk due to its tectonic environment, high population density and exposure concentration along its coastlines. It is therefore of paramount interest to quantify and differentiate absolute and relative tsunami hazard and risk on a countrywide scale. We quantify tsunami hazard in terms of inundation depth for the entire Japanese coastline with a probabilistic tsunami hazard assessment utilizing the earthquake source information of the 2017 Japanese seismic hazard model. We simulate a stochastic event set for offshore earthquake sources and generate, for each single source with MW ≥ 7.5, non-uniform finite-fault slip models. We calculate elastic seafloor and landmass deformations that serve as initial conditions to high-resolution numerical modelling of tsunami wave propagation and coastal inundations by solving the non-linear shallow water equation. Variable land surface roughness based on land cover data is used to simulate accurate hydraulics of coastal inundation.We differentiate tsunami hazard by inundation depth hazard curves and inundation depth return period maps aggregated to city ward polygons as meaningful administrative boundaries. We find mega-thrust events on the subduction interfaces constituting the largest hazard. However, events down to MW = 7.5 can contribute to substantial hazard in several regions along the coast. In particular for city wards within the Tokyo bay area, we find that earthquakes occurring on the Sagami trough and not the largest mega-thrust events on the Nankai trough, contribute to the highest inundation hazard. Our results also illustrate that tsunami hazard on the western Japanese coast is not negligible.

Oscillatory slip flow of Fe3O4 and Al2O3 nanoparticles in a vertical porous channel using Darcy's law with thermal radiation

AbstractThe heat transfer phenomena and oscillatory flow of an electrically conducting viscous nanofluid (NF) in a channel with porous walls and saturated porous media exposed to the thermal radiation are studied. The nanoparticles (NPs) Fe3O4 and Al2O3 are taken with water as base fluid along with nonuniform temperature and velocity slip at the wall of channel (y′ = 0). The basic laws of momentum and energy conservation are converted into the dimensionless system of the partial differential equations (PDEs) using similarity variables. Closed‐form solutions of these coupled PDEs are constructed for all values of time by taking the oscillatory pressure gradient. The physical insight of involved parameters on the fluid velocity, temperature profile, heat transfer rate, and surface friction is studied and analyzed graphically. It is noted from this study that the fluid velocity shows a decreasing behavior with the volume fraction of NPs. Furthermore, the amplitude of the oscillatory motion in case of skin friction decreases for a large magnetic field.

A non-uniform dip slip formula to calculate the coseismic deformation: Case study of Tohoku Mw9.0 Earthquake

AbstractThe distribution of slip faults along the fault plane plays a special role in the kinetic pattern of tectonic deformation. To better understand the coseismic deformation and geodynamics of the earthquake, this paper applied the pile-up theory and derived an analytical formula to describe the non-uniform slip distribution along the fault width. To validate the new formula, it was tested with the coseismic displacements at the global positioning system (GPS) stations for the Tohoku earthquake in 11 March, 2011. Then, the computed horizontal and vertical displacements calculated using NDSM were compared to back-slip model (BSM) using GPS data obtained from the Jet Propulsion Laboratory (JPL). Finally, the theoretical analysis revealed that the analytical formulas derived here can be perceived as the expansion and perfection of the uniform dislocation model. Meanwhile, our results showed that the characteristics of the spatial distribution deformation from NDSM are similar to those derived by GPS measurements. Furthermore, the near-field RMS errors indicated that the horizontal displacements estimated using NDSM is 27.5%, and 35.6% for the vertical components. Our new formulas and findings could assist better portray the crustal deformation in some region and geodynamics in specific earthquake.

Tsunami Hazard Evaluation in the Coquimbo Region Using Nonuniform Slip Distribution Sources

Correction| August 21, 2019 Tsunami Hazard Evaluation in the Coquimbo Region Using Nonuniform Slip Distribution Sources Mauricio Fuentes Serrano; Mauricio Fuentes Serrano Corresponding Author Search for other works by this author on: GSW Google Scholar Sebastián Riquelme Muñoz; Sebastián Riquelme Muñoz Search for other works by this author on: GSW Google Scholar Miguel Medina; Miguel Medina Search for other works by this author on: GSW Google Scholar Matias Mocanu; Matias Mocanu Search for other works by this author on: GSW Google Scholar Rodrigo Filippi Fernandez Rodrigo Filippi Fernandez Search for other works by this author on: GSW Google Scholar Author and Article Information Mauricio Fuentes Serrano Corresponding Author Sebastián Riquelme Muñoz Miguel Medina Matias Mocanu Rodrigo Filippi Fernandez Publisher: Seismological Society of America First Online: 21 Aug 2019 Online Issn: 1938-2057 Print Issn: 0895-0695 © Seismological Society of America Seismological Research Letters (2019) 90 (5): 2094. https://doi.org/10.1785/0220190189 Article history First Online: 21 Aug 2019 Connected Content Errata: Tsunami Hazard Evaluation in the Coquimbo Region Using Nonuniform Slip Distribution Sources Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Mauricio Fuentes Serrano, Sebastián Riquelme Muñoz, Miguel Medina, Matias Mocanu, Rodrigo Filippi Fernandez; Tsunami Hazard Evaluation in the Coquimbo Region Using Nonuniform Slip Distribution Sources. Seismological Research Letters 2019;; 90 (5): 2094. doi: https://doi.org/10.1785/0220190189 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietySeismological Research Letters Search Advanced Search In Fuentes Serrano et al. (2019), the captions for figures 5 and 6 omitted citations to the Aránguiz et al. (2018) reference. The corrected figures captions are as follows. Figure 5. Average maximum amplitude with its runup minimum, maximum, and average for different nesting level (Aránguiz et al., 2018). White box depicts the next nested level. (a) First nesting level; (b) second nesting level; (c) third nesting level; (d) fourth nesting level. The fifth is shown in a different figure. The color version of this figure is available only in the electronic edition. Figure 6. Global... View Original Article You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Source Characteristics of the 28 September 2018 Mw 7.5 Palu-Sulawesi, Indonesia (SE Asia) Earthquake Based on Inversion of Teleseismic Bodywaves

We study source characteristics of the September 28, 2017 Mw 7.5 Palu (Sulawesi, Indonesia) earthquake that occurred in central Sulawesi and triggered devastating tsunami waves along the coastal plains of the island. We apply point-source teleseismic P- and SH-body waveform inversion and kinematic slip inversion techniques to obtain double-couple source mechanism and comprehensive finite-fault slip model of the source. The overall results show a strike-slip faulting mechanism (strike: 353° ± 5°, dip: 65° ± 5° and rake angles: − 4° ± 5°) with a small amount of dip-slip component at a shallow focal depth of 16 ± 2 km associated with the NW–SE trending left-lateral Palu-Koro strike-slip fault in the central Sulawesi region. The P- wave first motion polarity readings recorded at near-field and regional seismic stations are found to be reasonably consistent with the source mechanism solution of the earthquake and estimated error limits. We have extensively studied and considered the rupture velocity to be about 4.1 km/s during the slip inversion as previously proposed by seismological and geodetic studies for this event. The obtained finite-fault slip distribution model displays a rupture starting from the hypocentre located at 16 km, and then it propagated south accompanied by high amount of displacement, and reached the surface. The model has two slip-patches of 2.0–4.0 m at north of the fault plane, and 5.0–6.3 m at south near Palu city, which is very well matched with the observed damage and destruction related to the earthquake. The fault length and width, average slip and stress drop values are estimated to be 150 km, 45 km, 1.5 m and 13 bars, respectively. We have also obtained total source duration to be about 40 s with the most of seismic energy released at 10 s and 25 s. Furthermore, a small dip-slip component is evidently observed from both source models, and we suggest that this oblique shear which reflects the bending of slip vector along the strike direction could be comparatively responsible for tsunami generation along the left-lateral Palu-Koro Fault. The validation of this hypothesis could be done by evaluating the results of the mathematical tsunami simulations based on the comprehensive non-uniform slip models along with a high-resolution bathymetry data, which provides the details of the continental shelf in Palu bay.