The Experts below are selected from a list of 300 Experts worldwide ranked by ideXlab platform
Masayuki Uemura - One of the best experts on this subject based on the ideXlab platform.
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Fundamental studies on the influence of wave loads on a trimaran’s cross-Deck Structure
Journal of Marine Science and Technology, 2019Co-Authors: Hajime Kihara, Junya Dobashi, Shigeyuki Hibi, Masayuki UemuraAbstract:For the design of trimaran Structures, a lot of knowledge is necessary, and particularly it is important at an initial design stage to collect the qualitative knowledge under what wave conditions the stress concentration will occur. In the present paper, some fundamental numerical studies are carried out for the structural analysis of the trimaran using the whole ship model, particularly focusing on the strength of the cross Deck. First, the hydrodynamic pressure for wave loads acting on the trimaran hulls is predicted based on the potential theory. These are input loads on the Structure analysis of the trimaran, and the validity of the present approach is discussed with results of towing tank tests. Additionally, the load transfers should be done appropriately for the Structure analysis. This is because the difference between the grid size of the hydrodynamic analysis and that of Structure analysis, for example, finite-element (FE) analysis, may lead to a drop of computational accuracy. Next, the global strength of the target trimaran is discussed using the design loads by the rules. Finally, the local strength analysis using FE model is studied and the elastic behavior of the cross-Deck Structure is investigated to collect the useful properties for the cross-Deck design.
Hajime Kihara - One of the best experts on this subject based on the ideXlab platform.
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Fundamental studies on the influence of wave loads on a trimaran’s cross-Deck Structure
Journal of Marine Science and Technology, 2019Co-Authors: Hajime Kihara, Junya Dobashi, Shigeyuki Hibi, Masayuki UemuraAbstract:For the design of trimaran Structures, a lot of knowledge is necessary, and particularly it is important at an initial design stage to collect the qualitative knowledge under what wave conditions the stress concentration will occur. In the present paper, some fundamental numerical studies are carried out for the structural analysis of the trimaran using the whole ship model, particularly focusing on the strength of the cross Deck. First, the hydrodynamic pressure for wave loads acting on the trimaran hulls is predicted based on the potential theory. These are input loads on the Structure analysis of the trimaran, and the validity of the present approach is discussed with results of towing tank tests. Additionally, the load transfers should be done appropriately for the Structure analysis. This is because the difference between the grid size of the hydrodynamic analysis and that of Structure analysis, for example, finite-element (FE) analysis, may lead to a drop of computational accuracy. Next, the global strength of the target trimaran is discussed using the design loads by the rules. Finally, the local strength analysis using FE model is studied and the elastic behavior of the cross-Deck Structure is investigated to collect the useful properties for the cross-Deck design.
R. K. Gaydukov - One of the best experts on this subject based on the ideXlab platform.
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A Compressible Fluid Flow with Double-Deck Structure Inside an Axially Symmetric Wavy-Wall Pipe
Russian Journal of Mathematical Physics, 2019Co-Authors: A. V. Fonareva, R. K. GaydukovAbstract:The problem of viscous compressible fluid flow in an axially symmetric pipe with small periodic irregularities on the wall is considered for large Reynolds numbers. An asymptotic solution with double-Deck Structure of the boundary layer and unperturbed core flow is obtained. Numerical investigations of the influence of the density of the core flow on the flow behavior in the near-wall region are presented.
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MultiDeck Structures of boundary layers in compressible flows
2019 Days on Diffraction (DD), 2019Co-Authors: R. K. Gaydukov, Vladimir G. DanilovAbstract:Equations describing the double- and triple-Deck Structure are demonstrated for the case of compressible flows along a small perturbed plate for large Reynolds numbers. Numerical and analytical investigations of the influence of the upstream flow on the behavior of the flow in the near-wall region are presented.
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Double-Deck Structure in the problem of a compressible flow along a plate with small localized irregularities on the surface
European Journal of Mechanics - B Fluids, 2018Co-Authors: R. K. GaydukovAbstract:Abstract We consider the stationary problem of flow of a viscous compressible subsonic fluid along a flat plate with small localized (hump-type) irregularities on the surface for large Reynolds numbers. We obtain a formal asymptotic solution with double-Deck Structure of the boundary layer. We present the results of numerical simulation of the flow in the thin boundary layer (i.e., in the near-boundary region).
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double Deck Structure of the boundary layer in the problem of a compressible flow along a plate with small irregularities on the surface
European Journal of Mechanics B-fluids, 2017Co-Authors: R. K. GaydukovAbstract:Abstract We consider the problem of a viscous compressible subsonic fluid flow along a flat plate with small periodic irregularities on the surface for large Reynolds numbers. We obtain a formal asymptotic solution with double-Deck Structure of the boundary layer. We present the results of numerical simulation of flow in the thin boundary layer (i.e., in the near-boundary region).
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Double-Deck Structure of the boundary layer in the problem of flow in an axially symmetric pipe with small irregularities on the wall for large Reynolds numbers
Russian Journal of Mathematical Physics, 2017Co-Authors: V. G. Danilov, R. K. GaydukovAbstract:The problem of flow of a viscous incompressible fluid in an axially symmetric pipe with small irregularities on the wall is considered. An asymptotic solution of the problem with the double-Deck Structure of the boundary layer and the unperturbed flow in the environment (the “core flow”) is obtained. The results of flow numerical simulation in the thin and “thick” boundary layers are given.
Akira Matsunawa - One of the best experts on this subject based on the ideXlab platform.
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thick sandwich panel fabrication for bridge Deck Structure and its joint strength
LAMP 2002: International Congress on Laser Advanced Materials Processing, 2003Co-Authors: Akikazu Kitagawa, Naoaki Fukuda, Shinnosuke Takeda, Akira MatsunawaAbstract:The purpose of this study is to evaluate the static strength of thick plate laser welded lap joint and the performance of thick sandwich panel for bridge Deck Structure. The strength of thin sheet laser welded lap joint whose thickness is less than 1.6 mm have been already reported, but the strength of thick plate laser welded lap joint whose thickness is more than 10 mm is not known. The authors believe this thick laser welded lap jont enable heavy industries to make a revolution on applying it for sandwich panel fabrication. Then, they have conducted mechanical tests of 10 mm + 6 mm thick laser welded lap joints to grasp their static strength. According to the obtained data, they fabricate a thick sandwich panel model of newly designed bridge Deck Structure for evaluation. The static lading test, cyclic loading test and collapsing test show that the thick sandwich panel has enough performance for the practical application.
T.h. Jansen - One of the best experts on this subject based on the ideXlab platform.
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Multidisciplinary Health Monitoring of a Steel Bridge Deck Structure
Structural Health Monitoring-an International Journal, 2013Co-Authors: P.l. Pahlavan, R.j.m. Pijpers, J.h. Paulissen, H.c. Hakkesteegt, T.h. JansenAbstract:Fatigue cracks in orthotropic bridge Decks are an important cause for the necessary renovation of existing bridges. Parallel utilization of various technologies based on different physical sensing principles can potentially maximize the efficiency of structural health monitoring (SHM) systems for these complex Structures. A multidisciplinary SHM system composed of acoustic emission, strain measurements, and vibration measurement has been applied to a test steel bridge Deck under a fatigue loading in a lab environment. Having the main focus on acoustic emission and strain measurement, the present paper provides an evaluation of the performance of the SHM system in terms of detection of the crack initiation, localization, and growth. During the destructive test, the strain measurement was employed as a local monitoring method, and acoustic emission was utilized as a local/global monitoring scheme. The monitoring performance was validated using visual inspection and time of flight diffraction (TOFD) measurements. Some of the main observations in this study are: (i) good agreement between the estimated crack size based on the strain measurement and TOFD measurement, (ii) the earlier detection of the crack activity by acoustic emission compared to the 10% deviation of the strain measured at a few millimeters away from the crack initiation location, and (iii) localization of multiple active cracks by acoustic emission.
