Kinematics Of Deformation Research Articles

Enhancing buckling analysis of functionally graded plates using unified and generalized higher-order shear deformation theories

This paper introduces a comprehensive framework for stability analysis of functionally graded plates under diverse in-plane loading conditions while employing higher-order shear deformation theories. For this purpose, a unified model, including all shear deformation kinematics, has been proposed. This unified model incorporates any number or type of shear transverse functions, encompassing all existing plate shear deformation theories. This inclusivity is achieved through the introduction of a unique parameter, denoted by ”n” representing the number of shear deformation functions in the displacement model. Such a unified model allows great flexibility in choosing among higher order theories when modeling the behavior of plates subjected to shear deformation, making it a valuable tool for applications in engineering and materials science. Besides, this allowed us to easily introduce a fifth-order theory used for the first time in the buckling analysis of FGM plates. The critical buckling loads expressions corresponding to the employed kinematics were derived and the calculated values are compared to those computed using the numerical solver. The comparison demonstrates the effectiveness and accuracy of the formulated expressions in predicting critical buckling loads under uniaxial and biaxial loading conditions.

Influence of basement high and detachment on the kinematics of a fold-and-thrust belt in the central South Yellow Sea Basin, China: Insights from analog modeling

A fold-and-thrust belt (FTB) characterized by a basement high and detachment layer was developed beneath the South Yellow Sea Basin, an important petroleum exploration target. In the central basin, magnetic anomalies have revealed the basement high developed under the Laoshan Uplift. Seismic reflection together with drilling data have revealed the Lower Silurian Gaojiabian Formation exceeding ∼500 m acting as a low-cohesion detachment layer. However, the influence of these features on regional structures and the consequent hydrocarbon preservation conditions remains unclear. This study examined the kinematic characteristics and deformation localization associated with the basement high and intermediate detachment, respectively and collectively, using four sandbox models and particle velocity analysis under the FTB framework. Model 1, the reference, used pure quartz sand without either feature. Model 2 examined the role of the intermediate detachment using glass microbeads, finding very limited effect in producing typical thin-skinned FTB. Model 3 considered the basement high, finding that it strongly constrained the deformation regime of the wedge. Model 4 examined both features and suggested combined influence on FTB deformation processes. In Model 2, with the absence of a pre-existing basement high, the intermediate detachment did not play a role in FTB deformation. In Model 3, with the absence of an intermediate detachment, deformation propagated along the surface of the basement high after reaching its edge. In Model 4, shortening propagated upward along the edge of the basement high and then into the intermediate detachment; moreover, comparable structural geometry to the prototype was produced, including both thick- and thin-skinned FTBs in nature. The results indicate that in the central South Yellow Sea Basin, structural layers between the basement high and detachment should similarly experience weak deformation; thus, good hydrocarbon preservation conditions can be expected there. This study is of significant importance to guide future petroleum exploration in the central South Yellow Sea Basin.

Reconstructability of Open‐Ocean Upper‐Layer Dynamics From Surface Observations Using Surface Quasigeostrophy (SQG) Theory

AbstractAlthough previous studies suggest that the surface quasigeostrophy (SQG) theory is practically applicable for subsurface reconstruction from sea surface observations, they mostly examine the reconstructability of density but seldom evaluate the velocities. Meanwhile, these studies all focus on the regions of energetic kinetic energy, and observational validation of the SQG reconstructability has been lacking in relatively quiescent mid‐ocean regions. We perform such validation in a typical open‐ocean area of the Northeast Atlantic, using a SQG‐based “interior plus surface quasigeostrophic” (isQG) method. The inputs to isQG include satellite‐derived sea surface height, temperature and salinity. The reconstructed density and horizontal velocities are assessed against long‐term in situ observations. Overall, reasonable isQG reconstructability is found during the period with elevated mesoscale activities. In particular, when satellite‐derived sea surface density anomaly (SSDA) is consistent with its in situ counterpart, the reconstructed density captures the observed mesoscale signals reasonably well, including the period with the density anomaly changing sign with depth. However, the density reconstruction is considerably degraded when the satellite‐derived SSDA has large uncertainties. The horizontal velocity reconstruction is less affected by the SSDA uncertainty, and shows a better resemblance to the observation. Using the reconstructed variables, we further diagnose vertical velocities, wisQG, via the three‐dimensional QG omega equation, and compare them to the mooring‐based vertical velocities, wmo, estimated through the nondiffusive density equation. During a 1‐month period with the best reconstructions of density and horizontal velocity, wisQG well reproduce the persistent downwelling pattern of wmo associated with the geostrophic kinematic deformation forcing.

Flexural vibration of elastic composite beams using a third-order deformation kinematics

The present study introduces a one-dimensional finite element (FE) model that utilizes third-order deformation kinematics to analyze the flexural vibration of two-layered composite beams with partial shear slip. The proposed model incorporates a three-node straight beam element, utilizing the field-consistent approach and full numerical integration of the stiffness matrix. This approach is adopted to effectively address stress oscillation and shear locking issues, ensuring accurate and reliable results. The analysis focuses on the third-order deformation kinematics of longitudinal displacement within the beam depth, examining each of the two layers individually. The interface between the two material layers is joined using deformable shear connectors, which are represented as dispersed shear springs over the length of the beam. This study focuses on conducting a flexural vibration analysis of two-layered composite beams. The analysis includes the examination of both free vibration and forced vibration responses while considering or omitting the influence of damping under various loading conditions. The validity of the proposed FE model is assessed by the utilization of a two-dimensional model developed within the ABAQUS software. Additionally, the suggested model is evaluated through the process of verification by comparing it with previously published results.

A magnetic fabric study of the origin of englacial debris bands at Fláajökull, Southeast Iceland

Two debris bands associated with an overdeepened basin in the terminus region of the Fláajökull glacier, Iceland, have been sampled for their ice and debris. Here the kinematics of deformation are investigated through anisotropy of magnetic susceptibly (AMS), microstructural analyses, and c-axis preferred orientations. Comparison of the crystallographic orientations of 180 grains and the AMS shape orientations of mineral inclusions in polycrystalline ice reveals a multi-maximum girdle oblique to the planar stratification and a record of near vertical triaxial ellipsoids. These two distinct fabrics can be attributed to both pure and simple shear suggesting a complex deformational history. In addition, AMS from an ice-free sediment ridge on the glacier surface indicates pure shear locally dominated strain. The physical properties of the debris bands, sedimentology and field observations suggest that they were sourced from the glacial bed and emplaced by highly pressurized water into localized fractures.

Theoretical evaluation of nonlinear thermomechanical deflection characteristics of damaged (cracked) layered composite structural panel bonded with shape memory alloy (SMA) fibre and experimental verification

Thermomechanical deflections of the cracked multi-layered composite panels were investigated numerically using full-scale geometrical nonlinearity and higher-order deformation kinematics. The panel is embedded with shape memory alloy (SMA) fiber to improve the structural strength and integrity under thermomechanical loadings. The theoretical model for the SMA-reinforced cracked laminated composite shell panel is derived considering the material and geometrical nonlinearity. The numerical and experimental cases were performed for the intact and damaged cylindrical panels by varying the environmental conditions. Additional examples of structural and geometrical parameters have been conducted, including SMA-related data.

Kinematic deformation and intensity assessment of the 2021 Maduo MS7.4 earthquake in Qinghai revealed by high-frequency GNSS

Rapid acquisition of the kinematic deformation field and seismic intensity distribution of large earthquakes is crucial for postseismic emergency rescue, disaster assessment, and future seismic risk research. The advancement of GNSS observation and data processing makes it play an important role in this field, especially the high-frequency GNSS. We used the differential positioning method to calculate the 1 HZ GNSS data from 98 sites within 1000 km of the MS7.4 Maduo earthquake epicenter. The kinematic deformation field and the distribution of the seismic intensity by using the peak ground velocity derived from displacement waveforms were obtained. The results show that: 1) Horizontal coseismic response deformation levels ranging from 25 mm to 301 mm can be observed within a 1000 km radius from the epicenter. Coseismic response deformation on the east and west sides shows bilateral asymmetry, which markedly differs from the symmetry presented by surface rupture. 2) The seismic intensity obtained through high-frequency GNSS and field investigations exhibits good consistency of the scope and orientation in the high seismic intensity area, although the former is generally slightly smaller than the latter. 3) There may exist obstacles on the eastern side of the seismogenic fault. The Maduo earthquake induced a certain tectonic stress loading effect on the western Kunlun Pass-Jiangcuo fault (KPJF) and Maqin-Maqu segment, resulting in higher seismic risk in the future.

Kinematics of crustal deformation along the central Himalaya

Kinematics of crustal deformation along the central Himalaya

Early Paleozoic oblique convergence from subduction to collision: Insights from timing and structural style of the transpressional dextral shear zone in the Qilian orogen, northern Tibet of China

Transpressional shear zones commonly occur in ancient and modern convergent plate boundaries to accommodate oblique plate convergence. The early Paleozoic Qilian orogen in northeastern Tibet records the subduction of Proto-Tethyan Ocean lithosphere and the accretion-collision of various magmatic arcs and continental terranes. This study focused on the Datong ductile shear zone, which represents the central part of the WNW-ESE−striking ductile shear zone along the northern margin of the Qilian block in the Qilian orogen. This structure bears key information about the evolution of oblique convergence during the early Paleozoic orogeny. The kinematics and timing of the Datong ductile shear zone were investigated via field-based, microstructural, and mica 40Ar/39Ar dating analyses. Mesostructural and microstructural data showed predominantly dextral strike-slip shearing within the Datong ductile shear zone. Microstructural features and quartz c-axis crystallographic preferred orientation patterns indicated that dextral ductile shearing occurred under lower-amphibolite-facies conditions (∼500−550 °C and ∼5.6 kbar) within the shear zone. Microstructures of quartz showed subgrain rotation (SGR) and grain boundary migration (GBM), suggesting dislocation creep−dominated deformation. A strain rate of 10−12 s−1 and a differential stress of 25−39 MPa were estimated by the rheological flow law and quartz paleopiezometry. Finite strain measurements indicated that all deformed rocks of the Datong ductile shear zone exhibit a weakly oblate ellipsoid near the plane strain. Kinematic vorticity (ranging 0.47−0.83) analysis suggested the coexistence of simple shear and pure shear strains within the Datong ductile shear zone, indicating a transpressional setting. Biotite and muscovite 40Ar/39Ar data showed that transpressional shearing deformation started in the Ordovician (before 453 Ma) and lasted to the Silurian (ca. 430 Ma). Our new data combined with regional geological data show that the deformation type, kinematics, and dynamics of the Datong ductile shear zone were controlled by the southward oblique subduction of the Paleo-Qilian Ocean (Proto-Tethyan Ocean) and the following oblique collision between the Qilian block and the Alxa block. The intensive transpressional deformation along the northern Qilian block may reflect strong coupling between the subducting Paleo-Qilian oceanic slab and the overriding Qilian block as well as a high degree of convergence obliquity during the ongoing early Paleozoic convergence.

Multi-source data analysis to assess the past and present kinematics of the Pisciotta Deep-Seated Gravitational Slope Deformation (southern Italy)

Although Deep-Seated Gravitational Slope Deformations are well-known in the literature, their evolution and kinematics are still poorly understood. Their behavior is often complex and characterized by small movements associated with steady-state creep, alternating with periods of stasis, or accelerating downslope movements that, in some cases, could result in sudden and catastrophic failure events. Therefore, a multidisciplinary approach is often required. In this work, we shed light on the complex geometry and kinematics of the Pisciotta DSGSD, a deep-seated roto-translational sliding involving structurally complex turbiditic rock mass and interacting with man-made infrastructures. To reveal the geometrical features and the spatial and temporal behavior of the analyzed phenomenon, a multidisciplinary investigation was performed. Typical DSGSD landforms were mapped employing in-situ surveys, aided by stereoscopic analysis of historical aerial images and high-resolution drone-based mapping. Structural data and ancillary ground-based surveys revealed the presence of a highly weathered and folded turbiditic sequence, with competent sandstone and calcarenite units alternated by tectonically disrupted, weak argillite and mudrock layers. Remote sensing measurements from optical imagery and Synthetic Aperture Radar satellite data assessed the DSGSD's past and current kinematics, allowing to distinguish a pre-failure period with accelerating displacement rates, a failure period with maximum displacement rates, and a current post-failure period with decelerating displacement rates. Analytical modeling established the deep reach (up to 85 m) of the studied DSGSD as it allowed the estimation of its bottom surface and volume, as verified by available boreholes and inclinometric measurements. Furthermore, numerical modeling outcomes highlighted how the progressive weakening and alteration of the DSGSD material, in conjunction with changes in groundwater dynamics, serve as the primary mechanisms driving the observed kinematics. The models also revealed the intricate interaction between the DSGSD and the neighboring infrastructures.

Mathematical modeling and numerical simulation of arterial dissection based on a novel surgeon's view.

This paper presents a mathematical model for arterial dissection based on a novel hypothesis proposed by a surgeon, Axel Haverich, see Haverich (Circulation 135(3):205-207, 2017. https://doi.org/10.1161/circulationaha.116.025407 ). In an attempt and based on clinical observations, he explained how three different arterial diseases, namely atherosclerosis, aneurysm and dissection have the same root in malfunctioning Vasa Vasorums (VVs) which are micro capillaries responsible for artery wall nourishment. The authors already proposed a mathematical framework for the modeling of atherosclerosis which is the thickening of the artery walls due to an inflammatory response to VVs dysfunction. A multiphysics model based on a phase-field approach coupled with mechanical deformation was proposed for this purpose. The kinematics of mechanical deformation was described using finite strain theory. The entire model is three-dimensional and fully based on a macroscopic continuum description. The objective here is to extend that model by incorporating a damage mechanism in order to capture the tearing (rupture) in the artery wall as a result of micro-injuries in VV. Unlike the existing damage-based model of the dissection in the literature, here the damage is driven by the internal bleeding (hematoma) rather than purely mechanical external loading. The numerical implementation is carried out using finite element method (FEM).

Salt Tectonics Versus Shortening: Recognizing Pre‐Orogenic Evaporite Deformation in Salt‐Bearing Fold‐And‐Thrust Belts on the Example of the Silica Nappe (Inner Western Carpathians)

AbstractRecognizing salt‐related structures and differentiating them from tectonic shortening‐related anticlines and synclines can be a very challenging task in salt‐bearing fold‐and‐thrust belts, especially in poor outcrop conditions. In this study, we explain several diagnostic structural and sedimentary features that may be used to distinguish pre‐orogenic halokinetic structures from shortening‐related structures on the example of the Silica Nappe (Inner Western Carpathians, Central Europe). Detailed structural mapping in this area resulted in the recognition of several pre‐orogenic salt‐related structures, including linear salt walls and minibasins. Initial evaporite movement started as early as the late Early Triassic, and widespread diapirism occurred during the Middle to Late Triassic, ultimately leading to facies differentiation, with carbonate platform growth in the subsiding minibasins and reduced basinal deposition on top of the diapirs. Later, the inherited salt structures localized the deformation during the Cretaceous Alpine orogeny, and exerted a strong control on the geometry and kinematics of the subsequent deformations. Our new interpretation explains previously unsolved structural problems in the Silica Nappe, like pre‐orogenic thickness variations during the post‐rift phase, frequent young‐on‐older type thrust contacts and multiple folding directions with variable vergencies. The results point out that the Silica Nappe is a fold‐and‐thrust belt, where pre‐orogenic salt tectonics and its effects on the fold‐and‐thrust belt evolution can be studied in detail.

Numerical prediction of thermoacoustic responses of CNT reinforced natural (luffa) fibre/epoxy hybrid composite and experimental verification

This research reported the thermoacoustic radiation characteristics of luffa fibre/epoxy hybridised with MW-CNT (multi-walled carbon nanotube) composite flat panel structures. The acoustic responses are evaluated under harmonic excitation and uniform thermal environments. The panel model is derived from a coupled scheme by merging two different computational techniques, i.e., finite element method, FEM (structural modelling) and boundary element method, BEM (fluid part), via higher-order deformation kinematics. Additionally, the higher-order panel model utilises an equivalent single-layer theory for computational purposes. The responses are obtained through MATLAB computer code from the derived mathematical formulation by customising the parameters (geometry and material). A few frequency responses with and without environmental effects are compared with experimental data from home-grown experimentation facilities. The impact of individual parameters is thoroughly analysed, and highlighted their significance in controlling the panel’s acoustic radiation behaviour. The findings of this study contribute to the understanding of the acoustic radiation properties of luffa fibre/epoxy hybridised with MW-CNT composite flat panels. The higher-order coupled FEM-BEM scheme-based tailored MATLAB code also provides a reliable computational tool for analysing various composite structural components for futuristic design. This research would be a valuable reference for optimising composite flat panel structural design and performance in engineering applications requiring enhanced vibroacoustic control.

Biomimetic Spun Silk Ionotronic Fibers for Intelligent Discrimination of Motions and Tactile Stimuli.

Innovation in the ionotronics field has significantly accelerated the development of ultraflexible devices and machines. However, it is still challenging to develop efficient ionotronic-based fibers with necessary stretchability, resilience, and conductivity due to inherent conflict in producing spinning dopes with both high polymer and ion concentrations and low viscosities. Inspired by the liquid crystalline spinning of animal silk, this study circumvents the inherent tradeoff in other spinning methods by dry spinning a nematic silk microfibril dope solution. The liquid crystalline texture allows the spinning dope to flow through the spinneret and form free-standing fibers under minimal external forces. The resultant silk-sourced ionotronic fibers (SSIFs) are highly stretchable, tough, resilient, and fatigue-resistant. These mechanical advantages ensure a rapid and recoverable electromechanical response of SSIFs to kinematic deformations. Further, the incorporation of SSIFs into core-shell triboelectric nanogenerator fibers provides outstanding stable and sensitive triboelectric response to precisely and sensitively perceive small pressures. Moreover, by implementing a combination of machine learning and Internet of Things techniques, the SSIFs can sort objects made of different materials. With these structural, processing, performance, and functional merits, the SSIFs prepared herein are expected to be applied in human-machine interfaces.

Insights into the deformation kinematics of Xieliupo landslide, Zhouqu, China, through remote sensing and geomorphological observations

Insights into the deformation kinematics of Xieliupo landslide, Zhouqu, China, through remote sensing and geomorphological observations

Spatial variation of pure and simple shear across transpressive shear zones: flow kinematics map of the Posada-Asinara shear zone (NE Sardinia, Italy)

Flow kinematics estimations are necessary to determine how the deformation is partitioned in shear zones at different scales. Combining different scales of structural analysis with quantitative vorticity constraint allows a more rigorous examination of the kinematics of deformation. The Posada-Asinara shear zone (PASZ) in northern Sardinia (Italy) is a crustal-scale km-thick transpressive shear zone, separating the High- from the Medium-Grade Metamorphic Complex. After microstructural analysis, the vorticity of the flow was estimated to investigate the southernmost boundary of the PASZ, highlighting a dominant pure shear component far from the core of the shear zone. These results have been integrated with existing data to derive a regional-scale flow kinematic map of the Baronie region, highlighting the potentiality of automated geostatistical mapping to become a powerful complementary tool in the investigation of flow kinematics in collisional environments.

On the relativistic spatial localization for massive real scalar Klein–Gordon quantum particles

I rigorously analyze a proposal, introduced by D.R. Terno, about a spatial localization observable for a Klein–Gordon massive real particle in terms of a Poincaré-covariant family of POVMs. I prove that these POVMs are actually a kinematic deformation of the Newton–Wigner PVMs. The first moment of one of these POVMs, however, exactly coincides with a restriction (on a core) of the Newton–Wigner self-adjoint position operator, though the second moment does not. This fact permits to preserve all nice properties of the Newton–Wigner position observable, dropping the unphysical features arising from the Hegerfeldt theorem. The considered POVM does not permit spatially sharply localized states, but it admits families of almost localized states with arbitrary precision. Next, I establish that the Terno localization observable satisfies part of a requirement introduced by D.P.L. Castrigiano about causal temporal evolution concerning the Lebesgue measurable spatial regions of any Minkowskian reference frame. The validity of the complete Castrigiano’s causality requirement is also proved for a notion of spatial localization which generalizes Terno’s one in a natural way.

Structural architecture and late Cenozoic tectonic evolution of the Ulsan Fault Zone, SE Korea: New insights from integration of geological and geophysical data

Integration of geological and geophysical data is essential to elucidate the configuration and geometry of surface and subsurface structures, as well as their long-term evolution. The NNW–SSE-striking incised valley and parallel mountain range in the southeastern margin of the Korean Peninsula, extending 50 km from Gyeongju to Ulsan cities, are together regarded as one of the most prominent geographical features in South Korea. This paper presents an investigation into the structural architecture and deformation history of the valley and mountain range during the late Cenozoic based on combined data from field observations and gravity and electrical resistivity surveys. Our results based on integrated and reconciled geological, structural, and geophysical data are as follows. First, the incised fault valley can be divided into 1) the northern part, which comprises several distributed buried or exposed fault strands; and 2) the southern part, which comprises a concentrated deformation zone along the eastern margin of the valley. Different deformation features between the two parts are controlled by the lithology of host rocks and by the location and geometry of the neighboring major structures, that is, the Yeonil Tectonic Line (YTL) and the Yangsan Fault. Second, we defined the Ulsan Fault Zone as a NNW–SSE-to N–S-striking fault within the incised valley and along the eastern margin of the valley. In particular, the constituent strands located along the eastern margin of the valley have acted mainly as an imbricate thrust zone, characterized by an east-side-up geometry with moderate to low dip angles and reverse-dominant kinematics in the shallow subsurface during the Quaternary. Third, reactivated strands within the Ulsan Fault Zone during the Quaternary are interpreted as shortcut faults developed in the footwall of Miocene subvertical structures, predominantly the YTL. In addition, movements on the Ulsan Fault Zone and the YTL during the Miocene to Quaternary were arrested by the NNE–SSW-striking Yangsan Fault, which was a prominent and mature pre-existing structure. Our results highlight the spatiotemporal structural variation in SE Korea and emphasize the strong control of the configuration and geometry of pre-existing structures on the distribution and characteristics (i.e., geometry and kinematics) of the subsequent deformation under changing tectonic environments through the late Cenozoic.

Finite deformation analysis of electro-active shells

In this contribution, a novel nonlinear formulation for the finite deformation analysis of shell-like structures made of dielectric polymers and subject to electrical loading is developed. The kinematics of mechanical deformation is described via a seven-parameter shell model. Moreover, a second-order Taylor expansion, containing three parameters, is proposed to approximate the electrical potential through the thickness of the shell. The combined mechanical and electrical parameters constitute a ten-parameter electro-shell model. After developing the variational formulation of the problem, a nonlinear finite element formulation for the numerical solution of the coupled electromechanical problem is also developed. The formulation is further enriched by the enhanced assumed strain method to alleviate locking in thin shells. Finally, the applicability of the proposed formulation in several benchmark examples is demonstrated. In particular, it is shown that the formulation can capture the results available in the literature with high accuracy.

ANALYSIS OF THE STATE OF STRESS AND DEFORMATION OF THE MATERIAL OF THE BILLET WHEN PLANTING BY THE RESOURCE-SAVING METHOD OF STAMPING BY ROLLING

The processes of planting blanks by the rolling stamping method allow for the efficient production of a wide range of high-quality products, but the possibility of material destruction during deformation prevents the expansion of their technological capabilities. Further development of the processes is possible through the development of new technological schemes based on the analysis of deformation kinematics and the appointment of favorable technological parameters, taking into account their influence on the stress-strain state and deformability of the material of the workpieces. In order to widely use the method of assessing the deformability of workpieces, a reliable technique is needed, which provides for the presence of a mathematical model of the trajectory of deformation of material particles in the coordinates "stress state indicator - accumulated plastic deformation before failure." The work uses an approach to finding an analytical representation of the deformation trajectory based on the construction of a differential equation between the components of plastic deformation increments, followed by the solution of this equation and the identification of its parameters based on experimental data. According to the results of the research, the deformation trajectories of the material particles of the peripheral surface of the flange when planting by rolling stamping method were schematically constructed in the coordinates "intensity of deformations - stress state indicator". Based on the built model, damage accumulation can be simulated by changing the values of the model parameters for different materials and deformation paths. An analytical representation of the deformation trajectory in a parametric form was obtained. The advantages of representing the deformation trajectory in the form of parametric equations are the convenience of analyzing these trajectories. The advantage of the model of the trajectory of deformation of material particles in the coordinates "stress state indicator - plastic strain accumulated before failure" is the absence of a material constant in the analytical expression for the stress state, and the consequence is additional convenience of analyzing ratios and selecting the value of the material constant based on experimental data.