Articles de revues : « Deformation Field »

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YAMAGUCHI, MASAHIRO. « GAUGE DEFORMATIONS OF CONFORMAL FIELD THEORIES AND ZAMOLODCHIKOV'S C-FUNCTION ». International Journal of Modern Physics A 05, n^o 22 (20 novembre 1990) : 4279–300. http://dx.doi.org/10.1142/s0217751x90001781.

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We study the deformations of conformal field theories in which the perturbing fields include the Virasoro secondary fields of the form L−1φ. We introduce the notion of gauge deformation which is an analogue of the off-shell gauge transformation in string theory. We also calculate Zamolodchikov's c-function and show that it is invariant under the gauge deformation.

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TRINCHERO, R. « SCALAR FIELD ON NON-INTEGER-DIMENSIONAL SPACES ». International Journal of Geometric Methods in Modern Physics 09, n^o 08 (29 octobre 2012) : 1250070. http://dx.doi.org/10.1142/s0219887812500703.

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Deformations of the canonical spectral triples over the n-dimensional torus are considered. These deformations have a discrete dimension spectrum consisting of non-integer values less than n. The differential algebra corresponding to these spectral triples is studied. No junk forms appear for non-vanishing deformation parameter. The action of a scalar field in these spaces is considered, leading to non-trivial extra structure compared to the integer-dimensional cases, which does not involve a loss of covariance. One-loop contributions are computed leading to finite results for non-vanishing deformation.

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Fan, Jinyan, Zhibiao Guo, Xiaobing Qiao, Zhigang Tao, Fengnian Wang et Chunshun Zhang. « Constant Resistance and Yielding Support Technology for Large Deformations of Surrounding Rocks in the Minxian Tunnel ». Advances in Civil Engineering 2020 (28 septembre 2020) : 1–13. http://dx.doi.org/10.1155/2020/8850686.

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During the excavation of the Minxian tunnel, problems of large deformations of surrounding rocks and failure of support structures appeared frequently, which caused serious influences on construction safety and costs of the tunnel. Based on laboratory analysis of mineral composition and field investigations on deformation characteristics of the surrounding rocks, the large deformation mechanism of surrounding rocks of the tunnel was considered as water-absorbing swelling molecules of carbonaceous slate and stress-induced asymmetric structural deformations of the surrounding rocks. The structural deformations of surrounding rocks mainly include bending deformation, interlayer sliding, and crushing failure of local rock blocks. Then, a new constant resistance and yielding support technology based on the constant resistance and large deformation (CRLD) anchor cable was proposed to control large deformations of surrounding rocks. The field tests and deformation monitoring were carried out. The monitoring results showed that compared with original support measure, the surrounding rock deformations, stresses of primary supports, and permanent lining using new support technology decreased greatly. Among them, the maximum deformation of surrounding rock was only 73 mm. The effects of field application and results of deformation monitoring showed that the new support technology can effectively control large deformations of the surrounding rocks in the Minxian tunnel.

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IBRAGIMOV, Kudaibergen, Darkhan ARTYKBAEV, Kanat BAIBOLOV et Kamol NAZAROV. « Field Deformation Stamp Experiments ». Trudy Universiteta, n^o 3 (2021) : 166–71. http://dx.doi.org/10.52209/1609-1825_2021_3_166.

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Hallberg, Håkan, et Kevin Hult Blixt. « Evaluation of Nanoscale Deformation Fields from Phase Field Crystal Simulations ». Metals 12, n^o 10 (28 septembre 2022) : 1630. http://dx.doi.org/10.3390/met12101630.

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Different methods for evaluation of displacement and strain fields based on phase field crystal (PFC) simulations are shown. Methods originally devised for molecular dynamics (MD) simulations or analysis of high-resolution microscopy images are adapted to a PFC setting, providing access to displacement and strain fields for systems of discrete atoms, such as in MD, as well as to continuous deformation fields. The latter being achieved by geometrical phase analysis. As part of the study, the application of prescribed non-affine deformations in a 3D structural PFC (XPFC) setting is demonstrated as well as an efficient numerical scheme for evaluation of PFC phase diagrams, such as, for example, those required to stabilize solid/liquid coexistence. The present study provides an expanded toolbox for using PFC simulations as a versatile numerical method in the analysis of material behavior at the atomic scale.

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Ligas, Marcin, Marek Banaś et Anna Szafarczyk. « A method for local approximation of a planar deformation field ». Reports on Geodesy and Geoinformatics 108, n^o 1 (10 octobre 2019) : 1–8. http://dx.doi.org/10.2478/rgg-2019-0007.

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AbstractWe present a method of approximation of a deformation field based on the local affine transformations constructed based on n nearest neighbors with respect to points of adopted grid. The local affine transformations are weighted by means of inverse distance squared between each grid point and observed points (nearest neighbors). This work uses a deformation gradient, although it is possible to use a displacement gradient instead – the two approaches are equivalent. To decompose the deformation gradient into components related to rigid motions (rotations, translations are excluded from the deformation gradient through differentiation process) and deformations, we used a polar decomposition and decomposition into a sum of symmetric and an anti-symmetric matrices (tensors). We discuss the results from both decompositions. Calibration of a local affine transformations model (i.e., number of nearest neighbors) is performed on observed points and is carried out in a cross-validation procedure. Verification of the method was conducted on simulated data-grids subjected to known (functionally generated) deformations, hence, known in every point of a study area.

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Bushenkova, Natalia A., et Olga A. Kuchay. « SEISMOTECTONIC DEFORMATIONS IN THE PACIFIC AND OKHOTSK LITHOSPHERIC PLATES CONTACT ZONE ». Interexpo GEO-Siberia 2, n^o 2 (21 mai 2021) : 9–16. http://dx.doi.org/10.33764/2618-981x-2021-2-2-9-16.

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The seismotectonic deformations were determined in the Pacific and Okhotsk (Eurasian) lithospheric plates subduction zone based on 2458 mechanisms of earthquake foci data for 1977-2019. The deformation features of medium in different deep layers are shown. The deformation field uniformity in the depth range of 1-70 km and the deformation field inhomogeneity for the submerged plate deep parts (105-200, 200-400 and 400-700 km) are revealed. One of the deformations field change reasons is the influence of ascending and, especially, descending currents of thermogravitational convection in the upper mantle sublithospheric part, in particular, the convection structure influence on the subducting plate geometry

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Perez-Payan, Sinuhe, M. Sabido, E. Mena et C. Yee-Romero. « Analysis of Scalar Field Cosmology with Phase Space Deformations ». Advances in High Energy Physics 2014 (2014) : 1–5. http://dx.doi.org/10.1155/2014/958137.

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Phase space deformations on scalar field cosmology are studied. The deformation is introduced by modifying the symplectic structure of the minisuperspace variables. The effects of the deformation are studied in the “C-frame” and the “NC-frame.” In order to remove the ambiguities of working on different frames, a new principle is introduced. When we impose that both frames should be physically equivalent, we conclude that the only possibility for this model, is to have an effective cosmological constantΛeff≥0. Finally we bound the parameter space forθandβ.

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KRIZ, IGOR. « PERTURBATIVE DEFORMATIONS OF CONFORMAL FIELD THEORIES REVISITED ». Reviews in Mathematical Physics 22, n^o 02 (mars 2010) : 117–92. http://dx.doi.org/10.1142/s0129055x10003916.

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The purpose of this paper is to revisit the theory of perturbative deformations of conformal field theory from a mathematically rigorous, purely worldsheet point of view. We specifically include the case of N = (2,2) conformal field theories. From this point of view, we find certain surprising obstructions, which appear to indicate that contrary to previous findings, not all deformations along marginal fields exist perturbatively. This includes the case of deformation of the Gepner model of the Fermat quintic along certain cc fields. In other cases, including Gepner models of K3-surfaces and the free field theory, our results coincides with known predictions. We give partial interpretation of our results via renormalization and mirror symmetry.

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Barkov, L. A., Marina N. Samodurova et O. A. Nevraeva. « Kinematic and Dynamic Conditions in Metal Rolling of Porous Materials ». Materials Science Forum 989 (mai 2020) : 705–10. http://dx.doi.org/10.4028/www.scientific.net/msf.989.705.

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Mathematical modeling of plastic deformations in rolling consists in a consequent combination of the general energetic relationship in plasticity and the variation inequality expressed the principle of minimum of entire deformation energy. A real deformation state in a plastic zone beneath rolls and corresponding kinematic and dynamics conditions on the contact surface are considered as a limited one for the consequent approximate deformation states and are found out by the method of approximated approach. Any realization of this method on personal computers requires a rational construction of a kinematic-possible velocity field in the spatial domain on plastic flow. Using the ordinary propositions and a new assumptions the authors have constructed a simple kinematic-possible velocity field in the plastic zone beneath rolls. On the base of the consequent approach in which the general energetic relationship and the variation inequality are interrelated the authors have been able to find out the geometric, kinematic and dynamics characteristics of plastic deformation’s states in metal rolling.

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ANCO, STEPHEN C. « GAUGE THEORY DEFORMATIONS AND NOVEL YANG–MILLS CHERN–SIMONS FIELD THEORIES WITH TORSION ». International Journal of Geometric Methods in Modern Physics 01, n^o 04 (août 2004) : 493–544. http://dx.doi.org/10.1142/s0219887804000265.

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A basic problem of classical field theory, which has attracted growing attention over the past decade, is to find and classify all nonlinear deformations of linear abelian gauge theories. The physical interest in studying deformations is to address uniqueness of known nonlinear interactions of gauge fields and to look systematically for theoretical possibilities for new interactions. Mathematically, the study of deformations aims to understand the rigidity of the nonlinear structure of gauge field theories and to uncover new types of nonlinear geometrical structures. The first part of this paper summarizes and significantly elaborates a field-theoretic deformation method developed in earlier work. Some key contributions presented here are, firstly, that the determining equations for deformation terms are shown to have an elegant formulation using Lie derivatives in the jet space associated with the gauge field variables. Secondly, the obstructions (integrability conditions) that must be satisfied by lowest-order deformations terms for existence of a deformation to higher orders are explicitly identified. Most importantly, a universal geometrical structure common to a large class of nonlinear gauge theory examples is uncovered. This structure is derived geometrically from the deformed gauge symmetry and is characterized by a covariant derivative operator plus a nonlinear field strength, related through the curvature of the covariant derivative. The scope of these results encompasses Yang–Mills theory, Freedman–Townsend theory, and Einstein gravity theory, in addition to their many interesting types of novel generalizations that have been found in the past several years. The second part of the paper presents a new geometrical type of Yang–Mills generalization in three dimensions motivated from considering torsion in the context of nonlinear sigma models with Lie group targets (chiral theories). The generalization is derived by a deformation analysis of linear abelian Yang–Mills Chern–Simons gauge theory. Torsion is introduced geometrically through a duality with chiral models obtained from the chiral field form of self-dual (2+2) dimensional Yang–Mills theory under reduction to (2+1) dimensions. Field-theoretic and geometric features of the resulting nonlinear gauge theories with torsion are discussed.

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Romero, Cristian, Dan Casas, Maurizio M. Chiaramonte et Miguel A. Otaduy. « Contact-centric deformation learning ». ACM Transactions on Graphics 41, n^o 4 (juillet 2022) : 1–11. http://dx.doi.org/10.1145/3528223.3530182.

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We propose a novel method to machine-learn highly detailed, nonlinear contact deformations for real-time dynamic simulation. We depart from previous deformation-learning strategies, and model contact deformations in a contact-centric manner. This strategy shows excellent generalization with respect to the object's configuration space, and it allows for simple and accurate learning. We complement the contact-centric learning strategy with two additional key ingredients: learning a continuous vector field of contact deformations, instead of a discrete approximation; and sparsifying the mapping between the contact configuration and contact deformations. These two ingredients further contribute to the accuracy, efficiency, and generalization of the method. We integrate our learning-based contact deformation model with subspace dynamics, showing real-time dynamic simulations with fine contact deformation detail.

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Wan, Qiang, Li Ming Wei, Zhen Kai Zhou et Yun Fei Li. « Dependence of Damage-Induced Magnetization on the Plastic Deformation for X80 Steel ». Applied Mechanics and Materials 330 (juin 2013) : 106–11. http://dx.doi.org/10.4028/www.scientific.net/amm.330.106.

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Metal magnetic memory (MMM) method is a novel, passive magnetic method for inspecting mechanical degradation of ferromagnetic components. In this paper, the correlation between plastic deformation and the deformation-induced magnetic field was experimentally investigated for the X80 steel. Various tensile plastic deformations are introduced into test pieces with different initial discontinuities. The surface strain distributions and normal natural magnetic fields component are measured after the tensile testings. The results show that the normal natural magnetic fields component are effective in capturing different deformation stages under tensions, the relationship between the intensity of damage-induced magnetization and the maximum plastic strain follows a simple formula proposed in this paper.

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Gu, J., H. Sol, S. He, A. Van Bael et J. Duflou. « OS9-1-1 Full field optical measurement of large deformation fields in Single Point Incremental Forming (SPIF) Processes ». Abstracts of ATEM : International Conference on Advanced Technology in Experimental Mechanics : Asian Conference on Experimental Mechanics 2007.6 (2007) : _OS9–1–1–1—_OS9–1–1–6. http://dx.doi.org/10.1299/jsmeatem.2007.6._os9-1-1-1.

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Morinelli, Vincenzo, et Karl-Henning Rehren. « Spacelike deformations : higher-helicity fields from scalar fields ». Letters in Mathematical Physics 110, n^o 8 (11 juin 2020) : 2019–38. http://dx.doi.org/10.1007/s11005-020-01294-w.

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Abstract In contrast to Hamiltonian perturbation theory which changes the time evolution, “spacelike deformations” proceed by changing the translations (momentum operators). The free Maxwell theory is only the first member of an infinite family of spacelike deformations of the complex massless Klein–Gordon quantum field into fields of higher helicity. A similar but simpler instance of spacelike deformation allows to increase the mass of scalar fields.

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Liu, Yin, Shoue Chen, Xiaobo Tan et Changyong Cao. « A Finite Element Framework for Magneto-Actuated Large Deformation and Instability of Slender Magneto-Active Elastomers ». International Journal of Applied Mechanics 12, n^o 01 (janvier 2020) : 2050013. http://dx.doi.org/10.1142/s1758825120500131.

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In this paper, we present an efficient finite element framework for modeling the finite deformations of slender magneto-active elastomers (MAE) under applied magnetic fields or currents. For the convenience of numerical modeling, magnetic field is defined at fixed spatial coordinates in the background space rather than in the elastic MAEs using material coordinates. The magnetic field will vary with free or localized currents while the spatial distribution of the magnetic field will evolve with the motion or deformation of the MAE materials, which is actuated by the surface or body forces induced by external magnetic fields or equivalent currents. A staggered strategy and a Riks method are introduced to solve the strongly coupled governing equations of the magnetic field and displacement field using finite element method. The mesh distortion along the interfaces between MAE domain and free-space domain is resolved by considering concurrent deformation of the mesh in these two domains. A few 2D numerical examples demonstrate the validity and efficiency of the developed model for simulating large deformation of MAE with non-uniform spatial magnetic field under different actuation sources such as free currents, magnetization or external magnetic field. This framework offers a new solution strategy for modeling mechano-magneto problems of MAEs and will help rational design and analysis of MAE-based actuators and soft robotics in the future.

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Sonntag, Nadja, Birgit Skrotzki, Robert Stegemann, Peter Löwe et Marc Kreutzbruck. « The Role of Surface Topography on Deformation-Induced Magnetization under Inhomogeneous Elastic-Plastic Deformation ». Materials 11, n^o 9 (23 août 2018) : 1518. http://dx.doi.org/10.3390/ma11091518.

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It is widely accepted that the magnetic state of a ferromagnetic material may be irreversibly altered by mechanical loading due to magnetoelastic effects. A novel standardized nondestructive testing (NDT) technique uses weak magnetic stray fields, which are assumed to arise from inhomogeneous deformation, for structural health monitoring (i.e., for detection and assessment of damage). However, the mechanical and microstructural complexity of damage has hitherto only been insufficiently considered. The aim of this study is to discuss the phenomenon of inhomogeneous “self-magnetization” of a polycrystalline ferromagnetic material under inhomogeneous deformation experimentally and with stronger material-mechanical focus. To this end, notched specimens were elastically and plastically deformed. Surface magnetic states were measured by a three-axis giant magnetoresistant (GMR) sensor and were compared with strain field (digital image correlation) and optical topography measurements. It is demonstrated that the stray fields do not solely form due to magnetoelastic effects. Instead, inhomogeneous plastic deformation causes topography, which is one of the main origins for the magnetic stray field formation. Additionally, if not considered, topography may falsify the magnetic signals due to variable lift-off values. The correlation of magnetic vector components with mechanical tensors, particularly for multiaxial stress/strain states and inhomogeneous elastic-plastic deformations remains an issue.

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Hu, Xin, Yanzhou Ji, Lei Chen, Ricardo A. Lebensohn, Long-Qing Chen et Xiangyang Cui. « Spectral phase-field model of deformation twinning and plastic deformation ». International Journal of Plasticity 143 (août 2021) : 103019. http://dx.doi.org/10.1016/j.ijplas.2021.103019.

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Vendnroux, G., N. Schmidt et W. G. Knauss. « Submicron deformation field measurements : Part 3. Demonstration of deformation determinations ». Experimental Mechanics 38, n^o 3 (septembre 1998) : 154–60. http://dx.doi.org/10.1007/bf02325737.

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Parizot, Oriane, Yves Missenard, Pierre Vergely, Frederic Haurine, Aurélie Noret, Guillaume Delpech, Jocelyn Barbarand et Philippe Sarda. « Tectonic Record of Deformation in Intraplate Domains : Case Study of Far-Field Deformation in the Grands Causses Area, France ». Geofluids 2020 (15 juillet 2020) : 1–19. http://dx.doi.org/10.1155/2020/7598137.

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Although tectonic plates are usually considered as rigid blocks, intraplate deformation such as lithospheric buckling or diffuse brittle deformation has been recognized for a long time. However, the origin of these deformations remains puzzling. Indeed, whereas the chronology of deformation at plate boundaries can be constrained by numerous methods (syntectonic sedimentary record, thermochronology, etc.), dating of brittle structures (faults, veins, and joints) in the far-field domains remains challenging, preventing a global interpretation of the system as a whole. In this contribution, we have combined a tectonic study with a synkinematical geochronological study of fault-related calcites of the Grands Causses intraplate domain, north of the Pyrenean orogeny. We show that these faults record a much longer history of deformation than previously thought. The Mesozoic extension, usually attributed to an early Jurassic Tethysian rifting event, probably lasted until the Barremian-Aptian epoch, in response to the Pyrenean basin’s opening. The so-called “Pyrenean deformation” of the Grands Causses domain, usually associated with the paroxysm of deformation in the belt during the late Eocene, began much earlier, around 100 Ma, and lasted for more than 60-70 Ma. This study demonstrates the high sensitivity of an intraplate domain (Grands Causses area) to record extensional or compressional deformations occurring at the edge of neighbouring plates.

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Han, Liang, et Yuning Song. « Analysis on Welding Temperature Field and Stress Field of Boring Bar of New Boring Machine ». Journal of Physics : Conference Series 2280, n^o 1 (1 juin 2022) : 012037. http://dx.doi.org/10.1088/1742-6596/2280/1/012037.

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Abstract Ansys software is used to simulate the welding process of the boring bar of the new cylinder head boring machine. The indirect coupling method is used to analyze the temperature field, then the stress field and deformation. It is found that for the double support structure, the highest temperature occurs at the outer stiffened plate of the small diameter end, and the lowest temperature occurs at both ends of the inner support structure. The deformation of the whole structure mainly comes from the axial deformation, and the maximum deformation occurs at the large diameter end of the outer rib plate. Because the role of the supporting web is to limit the large deformation of the whole structure, the structure at the small diameter end is firmer and has the ability of anti-deformation. In terms of technology, the influence caused by deformation can be compensated by the compensation design of machining amount.

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SOCHICHIU, CORNELIU. « ON DEFECT INDUCED GAUGE AND YUKAWA FIELDS IN GRAPHENE ». International Journal of Modern Physics B 26, n^o 05 (20 février 2012) : 1250055. http://dx.doi.org/10.1142/s0217979212500555.

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We consider lattice deformations (both continuous and topological) of the hexagonal lattice model describing the electronic wave function of graphene in the tight binding approximation. The deformation involves operators with the range up to next-to-neighbor. In the low energy limit, we find that these deformations give rise to couplings of the electronic Dirac field to an external scalar (Yukawa) and gauge fields. The fields are expressed in terms of original defects. As a by-product we establish that the next-to-nearest order is the minimal range of deformations which produces the complete gauge and scalar fields. We consider an example of Stone–Wales defect, and find the associated gauge field.

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Fialowski, Alice, Ashis Mandal et Goutam Mukherjee. « Versal Deformations of Leibniz Algebras ». Journal of K-Theory 3, n^o 2 (3 juin 2008) : 327–58. http://dx.doi.org/10.1017/is008004027jkt049.

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AbstractIn this work we consider deformations of Leibniz algebras over a field of characteristic zero. The main problem in deformation theory is to describe all non-equivalent deformations of a given object. We give a method to solve this problem completely, namely work out a construction of a versal deformation for a given Leibniz algebra, which induces all non-equivalent deformations and is unique on the infinitesimal level.

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Brabec, Martin, Jan Tippner, Václav Sebera, Jaromír Milch et Peter Rademacher. « Standard and non-standard deformation behaviour of European beech and Norway spruce during compression ». Holzforschung 69, n^o 9 (1 novembre 2015) : 1107–16. http://dx.doi.org/10.1515/hf-2014-0231.

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Abstract The goal of the study is to investigate the non-standard deformation behaviour of wood loaded by compression parallel to the grain. This is represented as a negative increment of strain in the range of plastic deformations when the load continues to increase. The objectives of this study are to point out this problem and to provide its description based on the deformation fields that have been analysed using three approaches: a) full-field optical technique based on digital image correlation (DIC); b) “clip on” extensometer and its virtual analogy, and c) crosshead displacement method. Further, the negative strain phenomenon was studied depending on the sample length. The samples were made from the European beech (Fagus sylvatica L.) and Norway spruce (Picea abies L. Karst.). Based on the strain analysis, it can be concluded that the deformation field consists of three sub-regions exhibiting different stiffness values (three-spring model). The failure of less stiff zones near the compression plates during the “non-standard” compression behaviour causes almost zero compression deformation of the stiffer middle zone or even leads to its expansion. The three-zone heterogeneity of deformation field induces a deviation of the displacement and strain measured by the proposed approaches. This phenomenon substantially influences the resulting longitudinal Young’s modulus and, therefore, should be of concern when measuring wood in such mode.

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Saxena, Shashank, Darius Diogo Barreto et Ajeet Kumar. « Extension–torsion–inflation coupling in compressible electroelastomeric thin tubes ». Mathematics and Mechanics of Solids 25, n^o 3 (28 novembre 2019) : 644–63. http://dx.doi.org/10.1177/1081286519886901.

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We present an axisymmetric and axially homogeneous variational formulation to obtain coupled extension–torsion–inflation deformation in compressible electroelastomeric tubes in the presence of axial and radial electric fields. We show that such deformations occur under the following two conditions: (1) only the axial electric field is imposed, with the electric poling direction in the tube (if present) lying in the radial plane; and (2) only the radial electric field is imposed within the tube, with the electric poling direction (if present) also along the radial direction. The poling direction in condition (1) generates helical anisotropy in the tube. We then obtain the governing differential equations necessary to solve the above deformation problem for thick tubes. We further apply the thin tube limit to obtain simplified algebraic equations to solve the same deformation problem. The effect of applied electric field parameters on the extension–inflation coupling and induced internal pressure vs. imposed inflation behavior is finally presented through numerical solution of the above obtained algebraic equations. The study will be useful in designing soft electroelastic tubular actuators.

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De Pascalis, Riccardo, Michel Destrade et Giuseppe Saccomandi. « The stress field in a pulled cork and some subtle points in the semi-inverse method of nonlinear elasticity ». Proceedings of the Royal Society A : Mathematical, Physical and Engineering Sciences 463, n^o 2087 (21 août 2007) : 2945–59. http://dx.doi.org/10.1098/rspa.2007.0010.

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In an attempt to describe cork-pulling, we model a cork as an incompressible rubber-like material and consider that it is subject to a helical shear deformation superimposed onto a shrink fit and a simple torsion. It turns out that this deformation field provides an insight into the possible appearance of secondary deformation fields for special classes of materials. We also find that these latent deformation fields are woken up by normal stress differences. We present some explicit examples based on the neo-Hookean, the generalized neo-Hookean and the Mooney–Rivlin forms of the strain-energy density. Using the simple exact solution found in the neo-Hookean case, we conjecture that it is advantageous to accompany the usual vertical axial force by a twisting moment, in order to extrude a cork from the neck of a bottle efficiently. Then we analyse departures from the neo-Hookean behaviour by exact and asymptotic analyses. In that process, we are able to give an elegant and analytic example of secondary (or latent) deformations in the framework of nonlinear elasticity.

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Fetisov, V. Р. « Structural aspects of deformation hardening with repeated drawing low carbon wire ». Litiyo i Metallurgiya (FOUNDRY PRODUCTION AND METALLURGY), n^o 2 (31 mai 2022) : 44–49. http://dx.doi.org/10.21122/1683-6065-2022-2-44-49.

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While repeated drawing of low carbon wire, a decrease in the grain size of ferrite reduces the parameters of deformation hardening in the initial field of deformations with parabolic hardening and increases in the field of substructural hardening with large and extra‑large total compressions. The transition from large to super‑large total deformations goes along with the development of dynamic return processes that reduce the rate of deformation hardening. Preliminary thermal softening of cold‑formed wire increases the strength gain during subsequent drawing and can be used to increase the total compression of the wire rod before intermediate heat treatment.

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Lee, Seongeyl, Jihong Hwang, M. Ravi Shankar, Srinivasan Chandrasekar et W. Dale Compton. « Large strain deformation field in machining ». Metallurgical and Materials Transactions A 37, n^o 5 (mai 2006) : 1633–43. http://dx.doi.org/10.1007/s11661-006-0105-z.

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Levine, Alex J., D. A. Head et F. C. MacKintosh. « The deformation field in semiflexible networks ». Journal of Physics : Condensed Matter 16, n^o 22 (22 mai 2004) : S2079—S2088. http://dx.doi.org/10.1088/0953-8984/16/22/006.

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Murthy, Tejas G., Christopher Saldana, Matthew Hudspeth et Rachid M'Saoubi. « Deformation field heterogeneity in punch indentation ». Proceedings of the Royal Society A : Mathematical, Physical and Engineering Sciences 470, n^o 2166 (8 juin 2014) : 20130807. http://dx.doi.org/10.1098/rspa.2013.0807.

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Plastic heterogeneity in indentation is fundamental for understanding mechanics of hardness testing and impression-based deformation processing methods. The heterogeneous deformation underlying plane-strain indentation was investigated in plastic loading of copper by a flat punch. Deformation parameters were measured, in situ , by tracking the motion of asperities in high-speed optical imaging. These measurements were coupled with multi-scale analyses of strength, microstructure and crystallographic texture in the vicinity of the indentation. Self-consistency is demonstrated in description of the deformation field using the in situ mechanics-based measurements and post-mortem materials characterization. Salient features of the punch indentation process elucidated include, among others, the presence of a dead-metal zone underneath the indenter, regions of intense strain rate (e.g. slip lines) and extent of the plastic flow field. Perhaps more intriguing are the transitions between shear-type and compression-type deformation modes over the indentation region that were quantified by the high-resolution crystallographic texture measurements. The evolution of the field concomitant to the progress of indentation is discussed and primary differences between the mechanics of indentation for a rigid perfectly plastic material and a strain-hardening material are described.

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Ismail, Mohd Idris Shah, Yasuhiro Okamoto et Akira Okada. « Thermo-Mechanical Analysis on Thermal Deformation of Thin Stainless Steel in Laser Micro-Welding ». International Journal of Manufacturing, Materials, and Mechanical Engineering 6, n^o 2 (avril 2016) : 51–66. http://dx.doi.org/10.4018/ijmmme.2016040104.

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In the present study, a three-dimensional finite element model has been developed to simulate the temperature, stress and deformation fields in continuous wave (CW) laser micro-welding of thin stainless steel sheet. The welding deformation was experimentally evaluated using a single-mode fiber laser with a high-speed scanning system. Application of developed thermal model demonstrated that the laser parameters, such as laser power, scanning velocity and spot diameter have a significant effect on temperature field and the weld pool. In the case of welding deformation, numerical simulation was carried out by an uncoupled thermo-mechanical model. The welding stress and deformation are generated by plastic deformation during the heating and cooling periods. It was confirmed that the residual stress is higher than yield strength and has strongest effect upon the welding deformation. The numerical simulated results have proved that the developed finite element model is effective to predict thermal histories, thermally induced stresses and welding deformations in the thin material.

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Yang, Yong, Li Qiang Tang, Yong Wang et Chen Feng. « Dynamic Growing Crack Tip Field in Visco-Elastic Compressible Material ». Key Engineering Materials 385-387 (juillet 2008) : 101–4. http://dx.doi.org/10.4028/www.scientific.net/kem.385-387.101.

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A mechanical model of the visco-elastic compressible material is established in order to investigate the viscous effect in dynamic growing crack-tip field. The constitutive equations on the visco-elastic compressible material are deducted. Through asymptotic analysis, it is shown that in the stable creep growing stage, the elastic-deformation and the visco-deformation are equally dominant in the near-tip field, as 1 ( 1) n r− − . The asymptotic solutions of separative variable in the crack-tip field are aslo obtained. According to numerical calculation, the curves of stress, stain and displacement are given. The results indicate that the near-tip fields are mainly governed by the creep exponent n and Mach number M ; the stress fields of mode I and mode II is slightly affected by the elastic compressible deformation; the strain and displacement fields of mode I are deeply affected by the elastic compressible deformation. However, the strain and displacement fields of mode II are less affected by the elastic compressible deformation. The asymptotic solutions of dynamic growing crack-tip field gained here can conveniently degenerate the incompressible case, when the Poisson ratio 0.5 ν→ , named as HR field. The conclusions can provide the references for further studying the dynamic growing crack-tip field in compressible material.

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Wei, Yukun, Anders B. Lundberg et Fredrik Resare. « Systematic slope stability assessment through deformation field monitoring ». E3S Web of Conferences 92 (2019) : 18009. http://dx.doi.org/10.1051/e3sconf/20199218009.

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Field monitoring is frequently carried out during excavations and other geotechnical activities and provides additional information during the execution of a construction project. The interpretation of field monitoring data is often obscured by measurement noise and disturbance, and a systematic approach to assess both the quality and implications of the field monitoring data is very helpful in geotechnical practice. The possibility to infer practical conclusions from the field monitoring data depends on the type of field measurements, especially in monitoring of the stability of slopes. Pore pressure measurements can serve as a direct measurement of utilized soil strength for a slope, while deformation measurements are significantly more ambiguous and complicates the interpretation. The assessment of slope stability through field monitoring of deformations requires inverse or back analysis of the soil properties, followed by a forward analysis of the resulting slope stability. Such an inverse or back analysis is frequently influenced by non-uniqueness of the material properties and the stability of the measurement data. Systematic approaches to inverse or back analysis have been demonstrated in the scientific literature, but the practical use of these methods is not entirely straight-forward. The current paper presents a case study of systematic slope stability assessment through field measurements of deformations with a review of the field monitoring programme, numerical simulations of deformations, and a simplified approach to back analysis of the soil parameters. The excavation of a slope in an urban environment including layers of organic clay covered with highly heterogeneous gravel fill is used as an example of geotechnical back analysis. The aim is to elucidate some of the challenges in geotechnical back analysis while providing some practical solutions for practice.

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Huebschmann, Johannes. « The formal Kuranishi parameterization via the universal homological perturbation theory solution of the deformation equation ». Georgian Mathematical Journal 25, n^o 4 (1 décembre 2018) : 529–44. http://dx.doi.org/10.1515/gmj-2018-0054.

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AbstractUsing homological perturbation theory, we develop a formal version of the miniversal deformation associated with a deformation problem controlled by a differential graded Lie algebra over a field of characteristic zero. Our approach includes a formal version of the Kuranishi method in the theory of deformations of complex manifolds.

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Gorthi, Subrahmanyam, Valérie Duay, Xavier Bresson, Meritxell Bach Cuadra, F. Javier Sánchez Castro, Claudio Pollo, Abdelkarim S. Allal et Jean-Philippe Thiran. « Active deformation fields : Dense deformation field estimation for atlas-based segmentation using the active contour framework ». Medical Image Analysis 15, n^o 6 (décembre 2011) : 787–800. http://dx.doi.org/10.1016/j.media.2011.05.008.

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Anischenko, Galyna, et Denys Lavinskyi. « Non-stationary phenomena in technological systems of electromagnetic processing of materials ». Bulletin of the National Technical University «KhPI» Series : Dynamics and Strength of Machines, n^o 2 (31 décembre 2022) : 39–42. http://dx.doi.org/10.20998/2078-9130.2022.2.270863.

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A large number of technical and technological facilities work under the action of electromagnetic fields. In electroconductive bodies have significant largest electromagnetic forces that can cause movement or deformation of structural elements. The creation of effective methods of analysis of the distribution of the electromagnetic field and coupled nonstationary deformation of structural elements is topical at present time. The article contains a mathematical formulation of the problem of nonstationary deformation of structural elements under the action of electromagnetic fields. Coupling of electromagnetic field and mechanical field is carried out with the help of local electromagnetic forces. Further made the transition to a variational formulation on the basis of the task of finding the minimum of the total energy of the system, which includes the energy of the electromagnetic field. For the numerical solution the finite element method is used. Nodal unknowns in this case are the magnetic vector potential and displacements. The proposed method is applied to non-stationary deformation of the "inductor-billet" technological operation of magnetic-pulse processing of metals. Some results of the deformation are presented. A large number of technical and technological facilities work under the action of electromagnetic fields. In electroconductive bodies have significant largest electromagnetic forces that can cause movement or deformation of structural elements. The creation of effective methods of analysis of the distribution of the electromagnetic field and coupled nonstationary deformation of structural elements is topical at present time. The article contains a mathematical formulation of the problem of nonstationary deformation of structural elements under the action of electromagnetic fields. Coupling of electromagnetic field and mechanical field is carried out with the help of local electromagnetic forces. Further made the transition to a variational formulation on the basis of the task of finding the minimum of the total energy of the system, which includes the energy of the electromagnetic field. For the numerical solution the finite element method is used. Nodal unknowns in this case are the magnetic vector potential and displacements. The proposed method is applied to non-stationary deformation of the "inductor-billet" technological operation of magnetic-pulse processing of metals. Some results of the deformation are presented. A large number of technical and technological facilities work under the action of electromagnetic fields. In electroconductive bodies have significant largest electromagnetic forces that can cause movement or deformation of structural elements. The creation of effective methods of analysis of the distribution of the electromagnetic field and coupled nonstationary deformation of structural elements is topical at present time. The article contains a mathematical formulation of the problem of nonstationary deformation of structural elements under the action of electromagnetic fields. Coupling of electromagnetic field and mechanical field is carried out with the help of local electromagnetic forces. Further made the transition to a variational formulation on the basis of the task of finding the minimum of the total energy of the system, which includes the energy of the electromagnetic field. For the numerical solution the finite element method is used. Nodal unknowns in this case are the magnetic vector potential and displacements. The proposed method is applied to non-stationary deformation of the "inductor-billet" technological operation of magnetic-pulse processing of metals. Some results of the deformation are presented.

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Berger, Tobias, et Krzysztof Klosin. « A deformation problem for Galois representations over imaginary quadratic fields ». Journal of the Institute of Mathematics of Jussieu 8, n^o 4 (30 janvier 2009) : 669–92. http://dx.doi.org/10.1017/s1474748009000036.

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AbstractWe prove the modularity of minimally ramified ordinary residually reducible p-adic Galois representations of an imaginary quadratic field F under certain assumptions. We first exhibit conditions under which the residual representation is unique up to isomorphism. Then we prove the existence of deformations arising from cuspforms on GL2(AF) via the Galois representations constructed by Taylor et al. We establish a sufficient condition (in terms of the non-existence of certain field extensions which in many cases can be reduced to a condition on an L-value) for the universal deformation ring to be a discrete valuation ring and in that case we prove an R=T theorem. We also study reducible deformations and show that no minimal characteristic 0 reducible deformation exists.

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Wang, Lei, Yu Sheng Li et Qing Song Huang. « Numerical Simulation Study on the Stress - Deformation Characteristics of Rock Mass of Luding Power Transmission Project in Sichuan ». Applied Mechanics and Materials 368-370 (août 2013) : 1688–92. http://dx.doi.org/10.4028/www.scientific.net/amm.368-370.1688.

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In this page, combination of finite element numerical simulation and discrete element numerical simulation is used to study the stress - deformation characteristics of rock mass of power transmission project site,whichclarifies the rock mass stress is mainly controlled by thegravitational field,the form of the potential deformationis dominated by compression deformation,andthere is no possibility of occurrence of the horizontal shear deformation.

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Bakker, DM, et RJ Davis. « Soil deformation observations in a vertisol under field traffic ». Soil Research 33, n^o 5 (1995) : 817. http://dx.doi.org/10.1071/sr9950817.

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A procedure based on the point grid method has been used to measure and visualize soil deformation resulting from tyre loads in a controlled traffic system. Several tests were performed in an irrigated heavy clay soil under various moisture conditions and two different geometries of the wheel tracks, recessed and elevated. This represented normal working conditions and illustrated that significant deformations were occurring. Deformations increased with moisture content and the number of passes. From the point grid displacements, bulk density changes were calculated which corresponded with the measured increases in density obtained from cores. Large displacements were observed when the soil was trafficked at high moisture content with little corresponding increase in bulk density. Soil structural degradation resulting from trafficking this soil at high moisture content should therefore be seen as a different process, such as a change in the orientation of clay particles or porosity of natural aggregates, rather than an increase in bulk density. Significant differences between vertical and horizontal displacements were found for the various tests. Increases in horizontal displacements were contributed to an increase in the degree of saturation. The recessed wheel tracks increased horizontal displacements due to the geometry of the wheel tracks.

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Yang, Yong, Guo Hui Wu et Li Qiang Tang. « Study on Quasi-Static Growing Crack Field in Visco-Elastic Compressible Material ». Key Engineering Materials 488-489 (septembre 2011) : 694–97. http://dx.doi.org/10.4028/www.scientific.net/kem.488-489.694.

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A mechanical model of the visco-elastic compressible material is established in order to investigate the viscous effect in quasi-static growing crack-tip field. The constitutive equations on the visco-elastic compressible material are deducted. Through asymptotic analysis, it is shown that in the stable creep growing stage, the elastic-deformation and the visco-deformation are equally dominant in the near-tip field, as r-1/(n-1). The asymptotic solutions of separative variable in the crack-tip field are aslo obtained. According to numerical calculation, the curves of stress, stain and displacement are given. The results indicate that the near-tip fields are mainly governed by the creep exponent ; the stress fields of mode I and mode II is slightly affected by the elastic compressible deformation; the strain and displacement fields of mode I are deeply affected by the elastic compressible deformation. However, the strain and displacement fields of mode II are less affected by the elastic compressible deformation. The asymptotic solutions of dynamic growing crack-tip field gained here can conveniently degenerate the incompressible case, when the Poisson ratio , named as HR field. The conclusions can provide the references for further studying the dynamic growing crack-tip field in compressible material.

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Xu, Dongtao, Changrong Ge, Ying Li et Yuejuan Liu. « Fluid-solid-heat coupling deformation analysis of the valve trims in a multistage pressure reducing valve ». PLOS ONE 17, n^o 1 (25 janvier 2022) : e0263076. http://dx.doi.org/10.1371/journal.pone.0263076.

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A multistage pressure reducing valve with specially designed pressure reducing components is presented in this paper. As the deformation of the valve trims under fluid-solid-heat coupling has an important influence on the operation reliability of the valve, a numerical simulation is carried out to analyse the flow field characteristic in the valve and radial deformation of the valve trims using the ANSYS software. And a deformation experiment is designed to validate the deformations of the valve trims at high temperature of 693.15 K. The results indicate that the simulation results agree well with the experimental data. Moreover, it is found that the temperature field has the most significant influence on the deformation of the valve trims, the radial deformations of the matching surface vary from 0.439 to 0.442 mm. And the radial deformations caused by other factors vary from 0.005 to 0.015 mm. In addition, as a novel indicator, the clearance after deformation of the matching surface is used to evaluate the operation reliability of the valve. By using the GAP function in ANSYS static module, the clearances of the matching surface are obtained at different openings under the condition of fluid-solid-heat coupling, further indicating that the initial clearance between the valve plug and inner sleeve should be greater than 0.014 mm to ensure the operation reliability of the valve.

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Sui, Xiaodan, Yuanjie Zheng, Yunlong He et Weikuan Jia. « Symmetric Deformable Registration via Learning a Pseudomean for MR Brain Images ». Journal of Healthcare Engineering 2021 (23 avril 2021) : 1–8. http://dx.doi.org/10.1155/2021/5520196.

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Image registration is a fundamental task in medical imaging analysis, which is commonly used during image-guided interventions and data fusion. In this paper, we present a deep learning architecture to symmetrically learn and predict the deformation field between a pair of images in an unsupervised fashion. To achieve this, we design a deep regression network to predict a deformation field that can be used to align the template-subject image pair. Specifically, instead of estimating the single deformation pathway to align the images, herein, we predict two halfway deformations, which can move the original template and subject into a pseudomean space simultaneously. Therefore, we train a symmetric registration network (S-Net) in this paper. By using a symmetric strategy, the registration can be more accurate and robust particularly on the images with large anatomical variations. Moreover, the smoothness of the deformation is also significantly improved. Experimental results have demonstrated that the trained model can directly predict the symmetric deformations on new image pairs from different databases, consistently producing accurate and robust registration results.

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Sidor, Jurij J. « Deformation Texture Modelling By Mean-Field And Full-Field Approaches ». Advanced Materials Letters 10, n^o 9 (1 septembre 2019) : 643–50. http://dx.doi.org/10.5185/amlett.2019.0030.

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Gong, Xinglong, Guojiang Liao et Shouhu Xuan. « Full-field deformation of magnetorheological elastomer under uniform magnetic field ». Applied Physics Letters 100, n^o 21 (21 mai 2012) : 211909. http://dx.doi.org/10.1063/1.4722789.

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Deshmukh, Shivraj D., et Rochish M. Thaokar. « Deformation and breakup of a leaky dielectric drop in a quadrupole electric field ». Journal of Fluid Mechanics 731 (2 septembre 2013) : 713–33. http://dx.doi.org/10.1017/jfm.2013.386.

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AbstractThe deformation and breakup of a leaky dielectric drop suspended in a leaky dielectric medium subjected to a quadrupole electric field are studied. Analytical (linear and nonlinear asymptotic expansions in the electric capillary number, $C{a}_{Q} $, a ratio of electric to capillary stress) and numerical (boundary element) methods are used. A complete phase diagram for the drop deformation in the $R$–$Q$ plane is presented, where $R$ and $Q$ are the non-dimensional ratios of the resistivities and dielectric constants, respectively, of the drop and the medium phase. The prolate and oblate deformations are mapped in the phase diagram, and the flow contours are also shown. The large deformation and breakup of a drop at higher $C{a}_{Q} $ are analysed using the boundary element method. Several non-trivial shapes are observed at the onset of breakup of a drop. A prolate drop always breaks above a certain critical value of $C{a}_{Q} $. In the oblate deformation cases, breakup as well as steady shapes are observed at a higher value of $C{a}_{Q} $. A detailed study of prolate and oblate deformation tendencies due to the normal and tangential electric stresses and the countervailing role of viscous stresses is presented. The circulation inside a drop is found to be more intense for a quadrupole field as compared with a uniform electric field. More intense internal circulations can lead to enhanced mixing characteristics and will have implications in microfluidic devices.

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Estabrook, Ian D., Hawa Racine Thiam, Matthieu Piel et Rhoda J. Hawkins. « Calculation of the force field required for nucleus deformation during cell migration through constrictions ». PLOS Computational Biology 17, n^o 5 (24 mai 2021) : e1008592. http://dx.doi.org/10.1371/journal.pcbi.1008592.

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During cell migration in confinement, the nucleus has to deform for a cell to pass through small constrictions. Such nuclear deformations require significant forces. A direct experimental measure of the deformation force field is extremely challenging. However, experimental images of nuclear shape are relatively easy to obtain. Therefore, here we present a method to calculate predictions of the deformation force field based purely on analysis of experimental images of nuclei before and after deformation. Such an inverse calculation is technically non-trivial and relies on a mechanical model for the nucleus. Here we compare two simple continuum elastic models of a cell nucleus undergoing deformation. In the first, we treat the nucleus as a homogeneous elastic solid and, in the second, as an elastic shell. For each of these models we calculate the force field required to produce the deformation given by experimental images of nuclei in dendritic cells migrating in microchannels with constrictions of controlled dimensions. These microfabricated channels provide a simplified confined environment mimicking that experienced by cells in tissues. Our calculations predict the forces felt by a deforming nucleus as a migrating cell encounters a constriction. Since a direct experimental measure of the deformation force field is very challenging and has not yet been achieved, our numerical approaches can make important predictions motivating further experiments, even though all the parameters are not yet available. We demonstrate the power of our method by showing how it predicts lateral forces corresponding to actin polymerisation around the nucleus, providing evidence for actin generated forces squeezing the sides of the nucleus as it enters a constriction. In addition, the algorithm we have developed could be adapted to analyse experimental images of deformation in other situations.

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Xu, Hao, Qi Zhou, Lei Yang, Minjing Liu, Dongyue Gao, Zhanjun Wu et Maosen Cao. « Reconstruction of full-field complex deformed shapes of thin-walled special-section beam structures based on in situ strain measurement ». Advances in Structural Engineering 23, n^o 15 (4 juillet 2020) : 3335–50. http://dx.doi.org/10.1177/1369433220937156.

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This study proposed a method capable of reconstructing complex deformations of thin-walled special-section beam structures subjected to highly coupled loading cases, in terms of the combination of tension/compression, biaxial bending, and warping torsion. The complex beam deformation was decoupled, depending on axial strain measurement strategy on beam surface, and leads to reconstructed full-field displacements (deformed shapes) as the linear superposition of deformations subject to individual loading types. Full-filed strain/stress distributions can then be derived based on the reconstructed displacements. Particular efforts were focused on reconstructing beam deformation subject to warping torsion, where both rotations angles and warping displacements across the beam cross-section and along the beam length were identified precisely. As a proof-of-concept validation, the effectiveness of the method was examined using finite element analysis, where the deformed shape of a thin-walled hat-section beam under the coupling between uniaxial bending and warping torsion was reconstructed., Experiments were conducted subsequently to reconstruct deformation of an aluminum hat-section beam using distributed optical fiber sensors for the measurement of axial strains on the beam surface. The reconstructed full-field deformed shapes of the beam were compared with the three-dimensional displacement signals captured using a non-contact digital image correlation system. The effectiveness of the proposed methodology for complex deformation reconstruction is possible to be extended to a variety of thin-walled beam-type structures which are typical in civil and aerospace engineering, showing potential contributions in fields such as on-line structural health monitoring and active structural control.

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Shao, Xin Yan, Xian Zhang Ling, Wei Zhang, Liang Tang, Li Na Wang et Min Wang. « Finite Element Analysis on Instantaneous Deformation and Consolidation Deformation of Saturated Soft Clay Foundation ». Advanced Materials Research 250-253 (mai 2011) : 3198–203. http://dx.doi.org/10.4028/www.scientific.net/amr.250-253.3198.

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Deformation analysis of foundation is an important research field in geotechnical engineering, especially analysis on instantaneous deformation and consolidation deformation of saturated soft clay foundations. In this paper, a computation model of instantaneous deformation and consolidation deformation was built on the basis of Biot Consolidation Theory and consideration of mechanism of instantaneous deformation and consolidation deformation and consideration of interrelation of both deformations. A method was proposed to determine initial pore water pressure in soil. Nonlinearity of soil deformation under drainage conditions was considered by combining Duncan-Zhang model with compaction curve of soil, and failure soil elements were processed by Mohr-Coulomb Failure Criteria. By numerical simulation, a nonlinear axi-symmetric FEM program was complied to solve foundation deformation and applied in calculation of soft ground tank settlement. Results show that the method presented in this paper is efficient and suitable to analyze instantaneous deformation and consolidation deformation.

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Rather, Ishfaq A., Asloob A. Rather, Ilídio Lopes, V. Dexheimer, A. A. Usmani et S. K. Patra. « Magnetic-field Induced Deformation in Hybrid Stars ». Astrophysical Journal 943, n^o 1 (1 janvier 2023) : 52. http://dx.doi.org/10.3847/1538-4357/aca85c.

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Abstract The effects of strong magnetic fields on the deconfinement phase transition expected to take place in the interior of massive neutron stars are studied in detail for the first time. For hadronic matter, the very general density-dependent relativistic mean field model is employed, while the simple, but effective vector-enhanced bag model is used to study quark matter. Magnetic-field effects are incorporated into the matter equation of state and in the general-relativity solutions, which also satisfy Maxwell’s equations. We find that for large values of magnetic dipole moment, the maximum mass, canonical mass radius, and dimensionless tidal deformability obtained for stars using spherically symmetric Tolman–Oppenheimer–Volkoff (TOV) equations and axisymmetric solutions attained through the LORENE library differ considerably. The deviations depend on the stiffness of the equation of state and on the star mass being analyzed. This points to the fact that, unlike what was assumed previously in the literature, magnetic field thresholds for the approximation of isotropic stars and the acceptable use of TOV equations depend on the matter composition and interactions.

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Shi, A., L. Jiang, L. Zhou, H. Tang, B. Wei et J. Li. « DEFORMATION EXTRACTION AND ANALYSIS OF COSEISMIC DEFORMATION FIELD BASED ON D-INSAR TECHNOLOGY ». International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLIII-B3-2022 (31 mai 2022) : 1161–66. http://dx.doi.org/10.5194/isprs-archives-xliii-b3-2022-1161-2022.

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Abstract. Extracting the seismic deformation field and analyzing the surface deformation after an earthquake occurs are of great significance for explaining earthquake mechanism and earthquake relief. Through the dual polarization mode of the two-pass method D-InSAR technology, this paper extracted the coseismic deformation fields based on two Sentinel-1A SAR images covering the Yulin earthquake area, and analyzed the surface deformation. The results show that the subsidence area obtained by VV and VH polarization modes are consistent. The uplift center areas are located in Tongxin Village in Rong County and Mapo Town in Luchuan County, and the subsidence center area is located in Fuxin Town of Beiliu City in the northeast. In the earthquake area, the maximum uplift derived by the VV mode SAR data is 12.1 cm, and the maximum subsidence is 5.8 cm. the maximum uplift obtained by the VH mode SAR data is 11.2 cm, and the maximum subsidence is 9 cm. The results obtained by the two polarization modes are consistent. D-InSAR technology can accurately obtain the coseismic deformation field, which provides data guarantee for the follow-up study of the inversion of seismic source parameters in the region.

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