Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 22 for “"underwater explosion"”.
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Frequency analysis of an underwater explosion
Thesis (B.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering, 1944.
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Design of an underwater explosion simulator
Thesis (Nav.E)--Massachusetts Institute of Technology, Dept. of Naval Architecture and Marine Engineering, 1963.
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Plastic response of a spherical shell to an underwater explosion
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1984.
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Numerical Study of Energy Loss Mechanisms in Oscillating Underwater Explosion (UNDEX) Bubbles
… high-explosive detonation was investigated for underwater explosion (UNDEX) events. The problem of over-prediction for long-term UNDEX bubble behavior in modern hydrocodes that is known to be due to neglected secondary energy-loss mechanisms is evaluated. A single secondary energy-loss mechanism …
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Modeling Underwater Explosion (UNDEX) Shock Effects for Vulnerability Assessment in Early Stage Ship Design
… and assesses a simplified tool for modeling underwater explosion shock effects during early naval ship concept design. A simplified fluid model using Taylor flat-plate theory is incorporated directly into the OpenFSI module code in Nastran and used to interface with the structural solver in …
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Finite and Spectral Element Methods for Modeling Far-Field Underwater Explosion Effects on Ships
The far-field underwater explosion (UNDEX) problem is a complicated problem dominated by two phenomena: the shock wave traveling through the fluid and the cavitation in the fluid. Both of these phenomena have a significant effect on the loading of ship structures subjected to UNDEX. An approach to …
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Computationally-effective Modeling of Far-field Underwater Explosion for Early-stage Surface Ship Design
The vulnerability of a ship to the impact of underwater explosions (UNDEX) and how to incorporate this factor into early-stage ship design is an important aspect in the ship survivability study. In this dissertation, attention is focused on the cost-efficient simulation of the ship response to a …
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An Underwater Explosion-Induced Ship Whipping Analysis Method for use in Early-Stage Ship Design
… the whipping response of a hull girder to underwater explosion (UNDEX) bubble pulse loading. A potential flow-based UNDEX bubble model capable of calculating the behavior of a migrating bubble for up to three pulses is developed. An approximate vertical plane ship vibration model is derived …
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Damping mechanisms and their effects on the whipping response of a submerged submarine subjected to an underwater explosion
Thesis (Nav. E.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1995, and Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1995.
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Assessment of LS-DYNA and Underwater Shock Analysis (USA) Tools for Modeling Far-Field Underwater Explosion Effects on Ships
… LS-DYNA and USA in modeling general far-field underwater explosions (UNDEX) by modeling a three-dimensional box barge that is subjected to a far-field underwater explosion. Past UNDEX models using these tools have not been validated by experiment and most are limited to very specific problems …
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A Runge Kutta Discontinuous Galerkin-Direct Ghost Fluid (RKDG-DGF) Method to Near-field Early-time Underwater Explosion (UNDEX) Simulations
… for numerically simulating a near-field underwater explosion (UNDEX). An UNDEX consists of a complicated sequence of events over a wide range of time scales. Due to the complex physics, separate simulations for near/far-field and early/late-time are common in practice. This work focuses …
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Investigation of Close Proximity Underwater Explosion Effects on a Ship-Like Structure Using the Multi-Material Arbitrary Lagrangian Eulerian Finite Element Method
… the characteristics of a close proximity underwater explosion and its effect on a ship-like structure. Finite element model tests are conducted to verify and validate the propagation of a pressure wave generated by an underwater explosion through a fluid medium, and the transmission of the …
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Development of a method for determining the response of a thin hemispherical shell to the initial pressure pulse of an underwater explosion
… a head-on attack by the initial shock wave of an underwater explosion. The shell which is fastened to the end of a fixed, semi-infinite tube of the same radius is surrounded by a high density fluid similar to water, and the internal cavity of the shell is filled with a low density fluid similar to …
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Free-Lagrange simulations of single cavitation bubble collapse.
… boundary types. The simulations resemble an underwater explosion or laser- or spark-generated bubble, where the bubble evolution is driven by a high initial pressure difference between the bubble content and the surrounding water. The significant advantages of this method in simulating highly …
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Exploring Immersed FEM, Material Design, and Biological Tissue Material Modeling
… and parameterization of lung tissue for Diver Underwater Explosion (UNDEX) simulations. In the first part, a shape optimization scheme utilizing a four-noded rectangular immersed-interface element is presented. This method eliminates the need for interface fitted mesh or mesh morphing, reducing …
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On Shock Capturing for Liquid and Gas Media
… problem of tracking a material interface in the underwater explosion problem. The Riemann problem for water and for a gas-water interface is analyzed, as a vehicle for applying the Godunov method to shock phenomena in liquid media. A by-product of this study is a mapping theorem which establishes …
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Attributes of Astrocyte Response to Mechano-Stimulation by High-Rate Overpressure
… a 20 psi high-rate overpressure scheme using an underwater explosion-driven device. Astrocytes experienced dynamic energetic fluctuations in response to overpressure which were followed by the assumption of a classically defined reactive phenotype. Results indicated specific roles for cationic …
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Numerical study of detonation in solid explosives under hydrodynamic and elastic-plastic confinement
… of a detonator in isolation, guided by an underwater explosion test. Following validation, the strength of the blast wave is examined at several distances from the detonator. Results show that the blast wave in the near field is asymmetric and stronger along the axis of the detonator. …
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Empirical investigation of underwater blast
… effective placement. It should be noted that an underwater charge can be used in two distinctly different types of application against a target ' a large charge at a distance from the target (eg a torpedo) or a small charge in direct contact (eg demolition charge or limpet mine). In the first …
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Multiphase Fluid-Material Interaction: Efficient Solution Algorithms and Shock-Dominated Applications
… and the bubble generated in a near-field underwater explosion motivates the next part of this dissertation. The second part of this dissertation investigates the yielding and collapse of an underwater thin-walled aluminum cylinder in near-field explosions. As the explosion intensity varies …
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