Bibliographies thématiques / Finite speed of propagation

Littérature scientifique sur le sujet « Finite speed of propagation »

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Publié le 10 mars 2023

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Articles de revues sur le sujet "Finite speed of propagation"

Mariano, Paolo Maria, et Marco Spadini. « Sources of Finite Speed Temperature Propagation ». Journal of Non-Equilibrium Thermodynamics 47, n^o 2 (9 février 2022) : 165–78. http://dx.doi.org/10.1515/jnet-2021-0078.

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Abstract The relation between heat flux and temperature gradient has been considered as a constitutive structure or as a balance law in different approaches. Both views may allow a description of heat conduction characterized by finite speed propagation of temperature disturbances. Such a result, which overcomes Fourier’s drawback of infinite speed propagation, can be obtained also by considering insufficient the representation of a conductor, even when it is considered to be rigid, rather than the sole relation between heat flux and temperature gradient. We comment this last view and describe the intersection with previous proposals. Eventually, we show how under Fourier’s law we can have traveling-wave-type temperature propagation when thermal microstructures are accounted for.

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Fujishima, Y., et J. Habermann. « Finite speed propagation for parabolic quasiminimizers ». Nonlinear Analysis 198 (septembre 2020) : 111891. http://dx.doi.org/10.1016/j.na.2020.111891.

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Roe, John. « Finite propagation speed and Connes' foliation algebra ». Mathematical Proceedings of the Cambridge Philosophical Society 102, n^o 3 (novembre 1987) : 459–66. http://dx.doi.org/10.1017/s0305004100067517.

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In [4], A. Connes has defined the convolution algebra associated to a foliation ℱ of the compact manifold M. Here is the graph or holonomy groupoid of the foliation ℱ (Winkelnkemper [15]). By forming the completion of in its regular representation, he obtains the C*-algebra C*{M, ℱ) associated to the foliation. The completeness of C*(M, ℱ) makes it easier to handle in some analytical contexts, but in others it seems to be too big, and it is necessary to consider instead some carefully selected dense subalgebra (cf. [6]). The purpose of this note is to show that certain spectral functions of leafwise elliptic operators, which might a priori be expected to belong to C*(M, ℱ), in fact belong to the more controllable dense subalgebra . We give a couple of applications, including a proof not passing through C*-algebras of Connes' index theorem for measured foliations [4]. It should be emphasized that the proof of that result offered here is essentially Connes' one, but the presentation may perhaps be more congenial to those who are not C*-algebra specialists.

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Andreu, F., V. Caselles, J. M. MazÃ³n et S. Moll. « Some diffusion equations with finite propagation speed ». PAMM 7, n^o 1 (décembre 2007) : 1040101–2. http://dx.doi.org/10.1002/pamm.200700126.

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Harvey, B. J., J. Methven et M. H. P. Ambaum. « Rossby wave propagation on potential vorticity fronts with finite width ». Journal of Fluid Mechanics 794 (6 avril 2016) : 775–97. http://dx.doi.org/10.1017/jfm.2016.180.

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The horizontal gradient of potential vorticity (PV) across the tropopause typically declines with lead time in global numerical weather forecasts and tends towards a steady value dependent on model resolution. This paper examines how spreading the tropopause PV contrast over a broader frontal zone affects the propagation of Rossby waves. The approach taken is to analyse Rossby waves on a PV front of finite width in a simple single-layer model. The dispersion relation for linear Rossby waves on a PV front of infinitesimal width is well known; here, an approximate correction is derived for the case of a finite-width front, valid in the limit that the front is narrow compared to the zonal wavelength. Broadening the front causes a decrease in both the jet speed and the ability of waves to propagate upstream. The contribution of these changes to Rossby wave phase speeds cancel at leading order. At second order the decrease in jet speed dominates, meaning phase speeds are slower on broader PV fronts. This asymptotic phase speed result is shown to hold for a wide class of single-layer dynamics with a varying range of PV inversion operators. The phase speed dependence on frontal width is verified by numerical simulations and also shown to be robust at finite wave amplitude, and estimates are made for the error in Rossby wave propagation speeds due to the PV gradient error present in numerical weather forecast models.

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Andreu, Fuensanta, Vicent Caselles, José M. Mazón et Salvador Moll. « Finite Propagation Speed for Limited Flux Diffusion Equations ». Archive for Rational Mechanics and Analysis 182, n^o 2 (3 avril 2006) : 269–97. http://dx.doi.org/10.1007/s00205-006-0428-3.

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Constantin, Adrian. « Finite propagation speed for the Camassa–Holm equation ». Journal of Mathematical Physics 46, n^o 2 (février 2005) : 023506. http://dx.doi.org/10.1063/1.1845603.

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McLaughlin, Joyce R., et Jeong-Rock Yoon. « Finite Propagation Speed of Waves in Anisotropic Viscoelastic Media ». SIAM Journal on Applied Mathematics 77, n^o 6 (janvier 2017) : 1921–36. http://dx.doi.org/10.1137/16m1099959.

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Bonafede, S., G. R. Cirmi et A. F. Tedeev. « Finite Speed of Propagation for the Porous Media Equation ». SIAM Journal on Mathematical Analysis 29, n^o 6 (novembre 1998) : 1381–98. http://dx.doi.org/10.1137/s0036141096298072.

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Remling, Christian. « Finite propagation speed and kernel estimates for Schrödinger operators ». Proceedings of the American Mathematical Society 135, n^o 10 (1 octobre 2007) : 3329–41. http://dx.doi.org/10.1090/s0002-9939-07-08857-0.

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Thèses sur le sujet "Finite speed of propagation"

Barua, Suchi. « Modelling and analysis of semiconductor optical amplifiers for high-speed communication systems using finite-difference beam propagation method ». Thesis, Curtin University, 2014. http://hdl.handle.net/20.500.11937/1406.

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Semiconductor optical amplifiers (SOAs) have attracted lots of interests because of their application potential in the field of optical communications. The output pulse of SOA can be changed due to the variation of input parameters such as input pulse shape, input pulse width, input pulse energy. For this reason, in this research pulse shape dependent propagation characteristics and gain saturation characteristics depending on different parameters have been analyzed and compared for faster communication systems.

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Yao, Lan. « Experimental and numerical study of dynamic crack propagation in ice under impact loading ». Thesis, Lyon, 2016. http://www.theses.fr/2016LYSEI043/document.

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Les phénomènes liés au comportement à la rupture de la glace sous impact sont fréquents dans le génie civil, pour les structures offshore, et les processus de dégivrage. Pour réduire les dommages causés par l'impact de la glace et optimiser la conception des structures ou des machines, l'étude sur le comportement à la rupture dynamique de la glace sous impact est nécessaire. Ces travaux de thèse portent donc sur la propagation dynamique des fissures dans la glace sous impact. Une série d'expériences d'impact est réalisée avec un dispositif de barres de Hopkinson. La température est contrôlée par une chambre de refroidissement. Le processus dynamique de la rupture de la glace est enregistré avec une caméra à grande vitesse et ensuite analysé par des méthodes d'analyse d'images. La méthode des éléments finis étendus complète cette analyse pour évaluer la ténacité dynamique. Au premier abord, le comportement dynamique de la glace sous impact est étudié avec des échantillons cylindriques afin d'établir la relation contrainte-déformation dynamique qui sera utilisée dans les simulations numériques plus tard. Nous avons observé de multi-fissuration dans les expériences sur les échantillons cylindriques mais son étude est trop difficile à mener. Pour mieux comprendre la propagation des fissures dans la glace, des échantillons rectangulaires avec une pré-fissure sont employés. En ajustant la vitesse d'impact on aboutit à la rupture des spécimens avec une fissure principale à partir de la pré-fissure. L'histoire de la propagation de fissure et de sa vitesse sont évaluées par analyse d'images basée sur les niveaux de gris et par corrélation d'images. La vitesse de propagation de la fissure principale est identifiée dans la plage de 450 à 610 m/s ce qui confirme les résultats précédents. Elle varie légèrement au cours de la propagation, dans un premier temps elle augmente et se maintient constante ensuite et diminue à la fin. Les paramètres obtenus expérimentalement, tels que la vitesse d'impact et la vitesse de propagation de fissure, sont utilisés pour la simulation avec la méthode des éléments finis étendus. La ténacité d'initiation dynamique et la ténacité dynamique en propagation de fissure sont déterminées lorsque la simulation correspond aux expériences. Les résultats indiquent que la ténacité dynamique en propagation de fissure est linéaire vis à vis de la vitesse de propagation et semble indépendante de la température dans l'intervalle -15 à -1 degrés
The phenomena relating to the fracture behaviour of ice under impact loading are common in civil engineering, for offshore structures, and de-ice processes. To reduce the damage caused by ice impact and to optimize the design of structures or machines, the investigation on the dynamic fracture behaviour of ice under impact loading is needed. This work focuses on the dynamic crack propagation in ice under impact loading. A series of impact experiments is conducted with the Split Hopkinson Pressure Bar. The temperature is controlled by a cooling chamber. The dynamic process of the ice fracture is recorded with a high speed camera and then analysed by image methods. The extended finite element method is complementary to evaluate dynamic fracture toughness at the onset and during the propagation. The dynamic behaviour of ice under impact loading is firstly investigated with cylindrical specimen in order to obtain the dynamic stress-strain relation which will be used in later simulation. We observed multiple cracks in the experiments on the cylindrical specimens but their study is too complicated. To better understand the crack propagation in ice, a rectangular specimen with a pre-crack is employed. By controlling the impact velocity, the specimen fractures with a main crack starting from the pre-crack. The crack propagation history and velocity are evaluated by image analysis based on grey-scale and digital image correlation. The main crack propagation velocity is identified in the range of 450 to 610 m/s which confirms the previous results. It slightly varies during the propagation, first increases and keeps constant and then decreases. The experimentally obtained parameters, such as impact velocity and crack propagation velocity, are used for simulations with the extended finite element method. The dynamic crack initiation toughness and dynamic crack growth toughness are determined when the simulation fits the experiments. The results indicate that the dynamic crack growth toughness is linearly associated with crack propagation velocity and seems temperature independent in the range -15 to -1 degrees

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Li, Liangpan. « Local spectral asymptotics and heat kernel bounds for Dirac and Laplace operators ». Thesis, Loughborough University, 2016. https://dspace.lboro.ac.uk/2134/23004.

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In this dissertation we study non-negative self-adjoint Laplace type operators acting on smooth sections of a vector bundle. First, we assume base manifolds are compact, boundaryless, and Riemannian. We start from the Fourier integral operator representation of half-wave operators, continue with spectral zeta functions, heat and resolvent trace asymptotic expansions, and end with the quantitative Wodzicki residue method. In particular, all of the asymptotic coefficients of the microlocalized spectral counting function can be explicitly given and clearly interpreted. With the auxiliary pseudo-differential operators ranging all smooth endomorphisms of the given bundle, we obtain certain asymptotic estimates about the integral kernel of heat operators. As applications, we study spectral asymptotics of Dirac type operators such as characterizing those for which the second coefficient vanishes. Next, we assume vector bundles are trivial and base manifolds are Euclidean domains, and study non-negative self-adjoint extensions of the Laplace operator which acts component-wise on compactly supported smooth functions. Using finite propagation speed estimates for wave equations and explicit Fourier Tauberian theorems obtained by Yuri Safarov, we establish the principle of not feeling the boundary estimates for the heat kernel of these operators. In particular, the implied constants are independent of self-adjoint extensions. As a by-product, we affirmatively answer a question about upper estimate for the Neumann heat kernel. Finally, we study some specific values of the spectral zeta function of two-dimensional Dirichlet Laplacians such as spectral determinant and Casimir energy. For numerical purposes we substantially improve the short-time Dirichlet heat trace asymptotics for polygons. This could be used to measure the spectral determinant and Casimir energy of polygons whenever the first several hundred or one thousand Dirichlet eigenvalues are known with high precision by other means.

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Bacon, David R. « Finite amplitude propagation in acoustic beams ». Thesis, University of Bath, 1986. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.483000.

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Meyer, Arnd, Frank Rabold et Matthias Scherzer. « Efficient finite element simulation of crack propagation ». Universitätsbibliothek Chemnitz, 2006. http://nbn-resolving.de/urn:nbn:de:swb:ch1-200601402.

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The preprint delivers an efficient solution technique for the numerical simulation of crack propagation of 2D linear elastic formulations based on finite elements together with the conjugate gradient method in order to solve the corresponding linear equation systems. The developed iterative numerical approach using hierarchical preconditioners comprehends the interesting feature that the hierarchical data structure will not be destroyed during crack propagation. Thus, one gets the possibility to simulate crack advance in a very effective numerical manner including adaptive mesh refinement and mesh coarsening. Test examples are presented to illustrate the efficiency of the given approach. Numerical simulations of crack propagation are compared with experimental data.

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Chao, Jenny C. 1976. « The propagation mechanism of high speed turbulent deflagrations / ». Thesis, McGill University, 2002. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=33961.

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The propagation regimes of combustion waves in a 30 cm by 30 cm square cross-sectioned tube with an obstacle array of staggered vertical cylindrical rods (with BR = 0.41 and BR = 0.19) are investigated. Mixtures of hydrogen, ethylene, propane, and methane with air at ambient conditions over a range of equivalence ratios are used. In contrast to the previous results obtained in circular cross-sectioned tubes, it is found that only the quasi-detonation regime and the slow turbulent deflagration regimes are observed for ethylene-air and for propane-air. The transition from the quasi-detonation regime to the slow turbulent deflagration regime occurs at D/lambda ≈ 1 (where D is the tube "diameter" and lambda is the detonation cell size). When D/lambda >> 1, the quasi-detonation velocities that are observed are similar to those in unobstructed smooth tubes. For hydrogen-air mixtures, it is found that there is a gradual transition from the quasi-detonation regime to the high speed turbulent deflagration regime. The high speed turbulent deflagration regime is also observed for methane-air mixtures near stoichiometric composition. (Abstract shortened by UMI.)

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Ordovas, Miquel Roland. « Covariant projection finite elements for transient wave propagation ». Thesis, Imperial College London, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.342285.

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Ritchie, Stephen John Kerr. « The high speed double torsion test ». Thesis, Imperial College London, 1996. http://hdl.handle.net/10044/1/11437.

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Jurgens, Henry Martin. « High-accuracy finite-difference schemes for linear wave propagation ». Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ27970.pdf.

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Lilla, Antonio de. « Finite difference seismic wave propagation using variable grid sizes ». Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/54427.

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Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 1997.
Includes bibliographical references (leaves 115-118).
by Antonio De Lilla.
M.S.

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Livres sur le sujet "Finite speed of propagation"

Pommier, Sylvie, Anthony Gravouil, Alain Combescure et Nicolas Moës. Extended Finite Element Method for Crack Propagation. Hoboken, NJ USA : John Wiley & Sons, Inc., 2013. http://dx.doi.org/10.1002/9781118622650.

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T, McDaniel S., dir. Ocean acoustic propagation by finite difference methods. Oxford : Pergamon Press, 1988.

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Zingg, D. W. An optimized finite-difference scheme for wave propagation problems. Washington, D. C : AIAA, 1993.

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E, Turkel, et Institute for Computer Applications in Science and Engineering., dir. Accurate finite difference methods for time-harmonic wave propagation. Hampton, Va : Institute for COmputer Applications in Science and Engineering, NASA Langley Research Center, 1994.

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Jurgens, Henry Martin. High-accuracy finite-difference schemes for linear wave propagation. Ottawa : National Library of Canada = Bibliothèque nationale du Canada, 1997.

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Lewicki, David G. Effect of speed (centrifugal load) on gear crack propagation direction. [Cleveland, Ohio] : National Aeronautics and Space Administration, Glenn Research Center, 2001.

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Epstein, Eric Martin. A comparison of finite-difference schemes for linear wave propagation problems. [Toronto, Ont.] : University of Toronto, Graduate Dept. of Aerospace Science and Engineering, 1995.

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Epstein, Eric Martin. A comparison of finite-difference schemes for linear wave propagation problems. Ottawa : National Library of Canada, 1994.

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LeVeque, Randall J. High resolution finite volume methods on arbitrary grids via wave propagation. Hampton, Va : National Aeronautics and Space Administration, Langley Research Center, 1988.

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H, Hung H., dir. Wave propagation for train-induced vibrations : A finite/infinite element approach. Hackensack, NJ : World Scientific, 2009.

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Chapitres de livres sur le sujet "Finite speed of propagation"

Andreu, Fuensanta, Vicent Caselles et José M. Mazón. « Diffusion Equations with Finite Speed of Propagation ». Dans Functional Analysis and Evolution Equations, 17–34. Basel : Birkhäuser Basel, 2007. http://dx.doi.org/10.1007/978-3-7643-7794-6_2.

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Cowling, Michael G., et Alessio Martini. « Sub-Finsler Geometry and Finite Propagation Speed ». Dans Trends in Harmonic Analysis, 147–205. Milano : Springer Milan, 2013. http://dx.doi.org/10.1007/978-88-470-2853-1_8.

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Hutt, Axel. « Finite Propagation Speeds in Spatially Extended Systems ». Dans Understanding Complex Systems, 151–76. Berlin, Heidelberg : Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-642-02329-3_5.

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Marinov, P., et P. Kiriazov. « On the propagation of temperature with finite wave speed in two-composite linear thermoelastic materials ». Dans Progress and Trends in Rheology II, 114–17. Heidelberg : Steinkopff, 1988. http://dx.doi.org/10.1007/978-3-642-49337-9_29.

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Weik, Martin H. « propagation speed ». Dans Computer Science and Communications Dictionary, 1357. Boston, MA : Springer US, 2000. http://dx.doi.org/10.1007/1-4020-0613-6_14949.

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Bancal, Jean-Daniel. « Finite-Speed Hidden Influences ». Dans Springer Theses, 89–96. Cham : Springer International Publishing, 2013. http://dx.doi.org/10.1007/978-3-319-01183-7_9.

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Rass, Linda, et John Radcliffe. « The asymptotic speed of propagation ». Dans Mathematical Surveys and Monographs, 99–133. Providence, Rhode Island : American Mathematical Society, 2003. http://dx.doi.org/10.1090/surv/102/05.

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Gdoutos, E. E. « Crack Speed During Dynamic Crack Propagation ». Dans Problems of Fracture Mechanics and Fatigue, 365–67. Dordrecht : Springer Netherlands, 2003. http://dx.doi.org/10.1007/978-94-017-2774-7_79.

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Gdoutos, E. E. « Speed and Acceleration of Crack Propagation ». Dans Problems of Fracture Mechanics and Fatigue, 377–82. Dordrecht : Springer Netherlands, 2003. http://dx.doi.org/10.1007/978-94-017-2774-7_82.

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Achar, Ramachandra, et Michel Nakhla. « Minimum Realization of Reduced-Order High-Speed Interconnect Macromodels ». Dans Signal Propagation on Interconnects, 23–44. Boston, MA : Springer US, 1998. http://dx.doi.org/10.1007/978-1-4757-6512-0_3.

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Actes de conférences sur le sujet "Finite speed of propagation"

Shnaid, Isaac. « Governing Equations for Heat Conduction With Finite Speed of Heat Propagation ». Dans ASME 2002 International Mechanical Engineering Congress and Exposition. ASMEDC, 2002. http://dx.doi.org/10.1115/imece2002-33855.

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In heat conduction, two different analytical approaches exist. The classical approach is based on a parabolic type Fourier equation with infinite speed of heat propagation. The second approach employs the hyperbolic type governing equation assuming finite speed of heat propagation. This approach requires fundamental modifications of classical thermodynamics which are developed in the frame of extended thermodynamics. In this work, governing equations for heat conduction with finite speed of heat propagation are derived directly from classical thermodynamics. For a linear flow of heat, the developed governing equation is linear and of parabolic type. In a three dimensional case, the system of nonlinear equations is formulated. Analytical solutions of the equations for linear flow of heat are obtained, and their analysis shows characteristic features of heat propagation with finite speed, being fully consistent with classical thermodynamics.

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Vafaeian, Behzad, Yuchin Wu, Michael R. Doschak, Marwan El-Rich, Tarek El-Bialy et Samer Adeeb. « Finite Element Simulation of Ultrasound Propagation in Trabecular Bone ». Dans ASME 2013 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/imece2013-64035.

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Quantitative ultrasound is used to identify healthy versus osteoporotic bone. However the physics of ultrasound propagation in trabecular media is still not sufficiently understood. This lack of understanding is reported to be an obstacle in further development of this bone assessment technique. Numerical models of wave propagation stand as a potentially successful tool to explain the various experimental observations. The main issue in the numerical modeling of wave propagation in trabecular bone is the complex geometry of the trabecular structures surrounded by a fluid (bone marrow). So far, the complex geometrical domain of trabecular structures has been approximated by finite difference grids for wave propagation analyses. In this work, numerical simulation of ultrasound propagation into trabecular bone sample is performed using the finite element method (FEM). A new procedure for numerical modeling of trabecular bone tailored for the FEM is introduced. The entire complex trabecular geometries of two cubic bone samples are reconstructed using computed microtomography data. For the first time a three dimensional finite element mesh using tetrahedral elements is generated for the two-phase medium of a trabecular bone. Separate meshes for the bony part and the filling marrow (considered as non-viscous water) are generated and acoustic-structure interaction condition is imposed on their interface. It is shown that the three-dimensional simulation using the FEM can predict ultrasound propagation phenomena observed in experiments: linear dependency of attenuation on frequency, the effect of bone volume on the attenuation and speed of sound, and the propagation of fast and slow waves. Moreover, the broadband ultrasound attenuation (BUA) for two ultrasonic signals propagating into a healthy and an osteoporotic sample are compared. A distinguishable difference in BUA between the two samples is observed expressing lower BUA for osteoporotic bone. Our developed model is the first three-dimensional finite element analysis model to compare the ultrasound propagation in healthy versus osteoporotic bone. The developed model can be further utilized as a tool to explain various experimental observations of quantitative ultrasound of bone.

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Hobæk, H. « Experiment on Finite Amplitude Sound Propagation in a Fluid with a Strong Sound Speed Gradient ». Dans INNOVATIONS IN NONLINEAR ACOUSTICS : ISNA17 - 17th International Symposium on Nonlinear Acoustics including the International Sonic Boom Forum. AIP, 2006. http://dx.doi.org/10.1063/1.2210424.

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Hermansson, Bjorn, et David Yevick. « Accurate field propagation procedures ». Dans OSA Annual Meeting. Washington, D.C. : Optica Publishing Group, 1990. http://dx.doi.org/10.1364/oam.1990.tua6.

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Standard beam-propagation methods such as the split-step fast Fourier transform, the split-operator finite difference methods, finite element methods, and the real-space technique are generally based on a second-order formula for the exponentiated sum of two non-commuting operators expressed in terms of the products of the exponents of the individual operators. In this presentation, we introduce an accurate analogous fourth-order formula. The increased and speed of the associated field propagation techniques over standard methods is verified by explicit computations on smoothly varying one-dimensional lens profiles.

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Ng, Eu-gene, Tahany I. El-Wardany, Mihaela Dumitrescu et Mohamed A. Elbestawi. « 3D Finite Element Analysis for the High Speed Machining of Hardened Steel ». Dans ASME 2002 International Mechanical Engineering Congress and Exposition. ASMEDC, 2002. http://dx.doi.org/10.1115/imece2002-33633.

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The objective of this research is to illustrate the importance of modeling the right/similar chip formation with experimental results. When machining ‘difficult to cut’ materials at high cutting speeds, segmented chips are usually formed. When modeling the cutting process, it is important to consider the type of chip formed, as this affects the stress field generated in the workpiece. The modeled chips have to be the same type as those obtained during experimental work. However very few published models were capable of modeling the 3D oblique cutting with segmented chip formation. This paper presents a finite element model that includes a user customized catastrophic slip criterion and crack propagation module to model segmented chip formation in orthogonal & oblique machining of hardened AISI 4340 steel (52±2 HRC). Predicted cutting forces and chip thickness for segmented chips were in close agreement with experimental data. The modeled plastic strain and temperature distribution/magnitude were very different for continuous and segmented chip formation.

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Fonzo, Andrea, Pietro Salvini, Massimo Di Biagio et Gianluca Mannucci. « Full History Burst Test Through Finite Element Analysis ». Dans 2002 4th International Pipeline Conference. ASMEDC, 2002. http://dx.doi.org/10.1115/ipc2002-27120.

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Ductile Fracture propagation phenomena have been widely investigated by researchers in the last years, with particular regard to large metallic structures such as pressurized vessels or gas pipelines. A large number of burst tests have been carried out by Centro Sviluppo Materiali S.p.A. (C.S.M.) in the last decades to identify a set of significant parameters characterizing fracture propagation conditions; the aim is to foresee the behavior (speed and its derivatives) of longitudinal running cracks. The optimal choice of these parameters is strongly helped by appropriate use of Finite Element analysis. To this goal a Finite Element software has been developed, it allows the correct computing of some particular aspects of fracture propagation and the behavior of pressured real gases during decompression. In the present paper a pipeline burst test, carried out on a X100 grade pipeline, and all laboratory tests and data manipulations necessary to build up the whole procedure have been discussed. One of the main objectives is the setting of a procedure able to identify the fracture parameters, when a ductile propagation occurs, avoiding any scatter due to transient effects.

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Sun, C. T., et C. Han. « Dynamic Mode I Fracture Toughness Test of Composites Using a Kolsky Bar ». Dans ASME 2001 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2001. http://dx.doi.org/10.1115/imece2001/amd-25404.

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Abstract Mode I dynamic delamination fracture was studied with two polymeric fiber reinforced composites. Wedge insertion fracture test on a Kolsky bar (or split Hopkinson pressure bar) apparatus was conducted. A speed about 1,000 m/s of Mode I delamination crack propagation was achieved using high rates of loading. Dynamic fracture and crack propagation were modeled by the finite element method. Dynamic initiation fracture toughnesses of both composites S2/8552 and IM7/977-3 were obtained. For IM7/977-3, dynamic fracture toughness of IM7/977-3 associated with the high speed of propagating crack was examined. It is found that the dynamic fracture toughness of the delamination crack propagating at speed up to 1,000 m/s approximately equals to the dynamic initiation fracture toughness, which is again approximately equal to the static fracture toughness.

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Buchanan, W. J. « Application of 3D finite-difference time-domain (FDTD) method to predict radiation from a PCB with high speed pulse propagation ». Dans 9th International Conference on Electromagnetic Compatibility. IEE, 1994. http://dx.doi.org/10.1049/cp:19940711.

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Shim, Do-Jun, Gery Wilkowski, David Rudland, Brian Rothwell et James Merritt. « Numerical Simulation of Dynamic Ductile Fracture Propagation Using Cohesive Zone Modeling ». Dans 2008 7th International Pipeline Conference. ASMEDC, 2008. http://dx.doi.org/10.1115/ipc2008-64049.

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This paper presents the development of a dynamic ductile crack growth model to simulate an axially running crack in a pipe by finite element analyses. The model was developed using the finite element (FE) program ABAQUS/Explicit. To simulate the ductile crack propagation, a cohesive zone model was employed. Moreover, the interaction between the gas decompression and the structural deformation was simulated by using an approximate three-dimensional pressure decay relationship from experimental results. The dynamic ductile crack growth model was employed to simulate 152.4 mm (6-inch) diameter pipe tests, where the measured fracture speed was used to calibrate the cohesive model parameters. From the simulation, the CTOA values were calculated during the dynamic ductile crack propagation. In order to validate the calculated CTOA value, drop-weight tear test (DWTT) experiments were conducted for the pipe material, where the CTOA was measured with high-speed video during the impact test. The calculated and measured CTOA values showed reasonable agreement. Finally, the developed model was employed to investigate the effect of pipe diameter on fracture speed for small-diameter pipes.

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Zhu, Zheng H., et Shaker A. Meguid. « Dynamic Stability Analysis of Aerial Refueling Hose/Drogue System by Finite Element Method ». Dans ASME 2008 International Mechanical Engineering Congress and Exposition. ASMEDC, 2008. http://dx.doi.org/10.1115/imece2008-67103.

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The present work investigates the effect of pertinent parameters such as the hose tension, tow point disturbance and vortex wake on the dynamic stability of the aerial refueling hose and drogue system by using the finite element method with an accurate and computationally efficient three-noded, curved beam element. The analysis results show that the conventional spectrum method is inappropriate for the dynamic stability analysis of the aerial refueling hose/drogue system. This is because the mechanism of instability due to the tow point disturbance is not the resonance of the refueling hose/drogue system but the wave propagation along the hose absorbing energy from the airflow as it travels downstream from the tow point, if the propagation speed is less than the airflow speed. The study also demonstrates that the vortex wake has a significant impact on the dynamics of the system. The short hose system will orbit with the vortex and the orbiting behavior will diminish as the hose length increases.

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Rapports d'organisations sur le sujet "Finite speed of propagation"

Henyey, Frank S. Acoustic Propagation Through Sound Speed Heterogeneity. Fort Belvoir, VA : Defense Technical Information Center, septembre 2009. http://dx.doi.org/10.21236/ada531751.

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Moran, Mark, Steve Ketcham et Roy Greenfield. Three Dimensional Finite-Difference Seismic Signal Propagation. Fort Belvoir, VA : Defense Technical Information Center, août 1999. http://dx.doi.org/10.21236/ada393626.

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Jha, Ratneshwar. Wavelet Spectral Finite Elements for Wave Propagation in Composite Plates. Fort Belvoir, VA : Defense Technical Information Center, février 2012. http://dx.doi.org/10.21236/ada565193.

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LeVeque, Randall J. High Resolution Finite Volume Methods on Arbitrary Grids via Wave Propagation. Fort Belvoir, VA : Defense Technical Information Center, octobre 1987. http://dx.doi.org/10.21236/ada211691.

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Teng, Yu-chiung. Finite-Element Modeling of the Blockage and Scattering of LG Propagation. Fort Belvoir, VA : Defense Technical Information Center, novembre 1993. http://dx.doi.org/10.21236/ada277430.

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Petersson, N., et B. Sjogreen. Serpentine : Finite Difference Methods for Wave Propagation in Second Order Formulation. Office of Scientific and Technical Information (OSTI), mars 2012. http://dx.doi.org/10.2172/1046802.

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Gao, Kai. Generalized and High-Order Multiscale Finite-Element Methods for Seismic Wave Propagation. Office of Scientific and Technical Information (OSTI), novembre 2018. http://dx.doi.org/10.2172/1481964.

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Wilson, D. K., et Lanbo Liu. Finite-Difference, Time-Domain Simulation of Sound Propagation in a Dynamic Atmosphere. Fort Belvoir, VA : Defense Technical Information Center, mai 2004. http://dx.doi.org/10.21236/ada423222.

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Paxton, Alan H. Propagation of 3-D Beams Using a Finite-Difference Algorithm : Practical Considerations. Fort Belvoir, VA : Defense Technical Information Center, mai 2011. http://dx.doi.org/10.21236/ada544032.

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Kees, C. E. Speed of Propagation for Some Models of Two-Phase Flow in Porous Media. Fort Belvoir, VA : Defense Technical Information Center, janvier 2004. http://dx.doi.org/10.21236/ada445637.

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