Fluid–Structure Interaction Effects in the Dynamic Response of Free-Standing Plates to Uniform Shock Loading

2006 ◽  
Vol 74 (5) ◽  
pp. 1042-1045 ◽  
Author(s):  
Nayden Kambouchev ◽  
Raul Radovitzky ◽  
Ludovic Noels
Keyword(s):  
Dynamic Response ◽  
Shock Intensity ◽  
Acoustic Waves ◽  
Shock Loading ◽  
Fluid Structure Interaction ◽  
Mass Range ◽  
Free Standing ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Transmitted Impulse

The problem of uniform shocks interacting with free-standing plates is studied analytically and numerically for arbitrary shock intensity and plate mass. The analysis is of interest in the design and interpretation of fluid–structure interaction (FSI) experiments in shock tubes. In contrast to previous work corresponding to the case of incident blast profiles of exponential distribution, all asymptotic limits obtained here are exact. The contributions include the extension of Taylor’s FSI analysis for acoustic waves, the exact analysis of the asymptotic limits of very heavy and very light plates for arbitrary shock intensity, and a general formula for the transmitted impulse in the intermediate plate mass range. One of the implications is that the impulse transmitted to the plate can be expressed univocally in terms of a single nondimensional compressible FSI parameter.

scholarly journals Experimental and Numerical Study on Modal Dynamic Response of Water-Surrounded Slender Bridge Pier with Pile Foundation

2017 ◽  
Vol 2017 ◽  
pp. 1-20 ◽  
Author(s):  
Yulin Deng ◽  
Qingkang Guo ◽  
Lueqin Xu
Keyword(s):  
Dynamic Response ◽  
Water Level ◽  
Pile Foundation ◽  
Numerical Study ◽  
Fluid Structure Interaction ◽  
Bridge Pier ◽  
Experimental Program ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Tip Mass

This paper presents an experimental program performed to study the effect of fluid-structure interaction on the modal dynamic response of water-surrounded slender bridge pier with pile foundation. A reduced scale slender bridge pier specimen is built and tested through forced vibration method. The vibration periods of the first four lateral modes, including the first two modes along x-axis and the first two modes along y-axis, are measured based on the specimen submerged by 16 levels of water and designated with 4 levels of tip mass. Three-dimensional (3D) finite-element models are established for the tested water-pier system and analyzed under various combined cases of water level and tip mass. Percentage increases of vibration periods with respect to dry vibration periods (i.e., vibration periods of the specimen without water) are determined as a function of water level and tip mass to evaluate the effect of fluid-structure interaction. The numerical results are successfully validated against the recorded test data. Based on the validated models, the modal hydrodynamic pressures are calculated to characterize the 3D distribution of hydrodynamic loads on the pier systems. The research provides a better illumination into the effect of fluid-structure interaction on the modal dynamic response of deepwater bridges.

Mitigation of Sliding Motion of a Cask-Canister by Fluid-Structure Interaction in an Annular Region

2011 ◽  
Author(s):  
Tomohiro Ito ◽  
Yoshihiro Fujiwara ◽  
Atsuhiko Shintani ◽  
Chihiro Nakagawa ◽  
Kazuhisa Furuta
Keyword(s):  
Equations Of Motion ◽  
Fluid Structure Interaction ◽  
Shaking Table ◽  
Annular Region ◽  
Test Model ◽  
Free Standing ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Sliding Motion ◽  
Standing Structure

The cask-canister system is a coaxial circular cylindrical structure in which several spent fuels are installed. This system is a free-standing structure thus, it is very important to reduce sliding motion for very large seismic excitations. In this study, we propose a mitigation method for sliding motion. Water is installed in an annular region between a cask and a canister. The equations of motion are derived taking fluid-structure interaction into consideration for nonlinear sliding motion analyses. Based on these equations, mitigation effects of sliding motions are studied analytically. Furthermore, a fundamental test model of a cask-canister system is fabricated and shaking table tests are conducted. From the analytical and test results, sliding motion mitigation effects are investigated.

Strongly Coupled Fluid–Structure Interaction in a Three-Dimensional Model Combustor During Limit Cycle Oscillations

2018 ◽  
Vol 140 (6) ◽  
Author(s):  
Mina Shahi ◽  
Jim B. W. Kok ◽  
J. C. Roman Casado ◽  
Artur K. Pozarlik
Keyword(s):  
Limit Cycle ◽  
Acoustic Waves ◽  
Fluid Structure Interaction ◽  
Transfer Model ◽  
Air Cooling ◽  
Three Dimensional Model ◽  
Structural Vibrations ◽  
Liner Material ◽  
Fluid Structure ◽  
Structure Interaction

Due to the high temperature of the flue gas flowing at high velocity and pressure, the wall cooling is extremely important for the liner of a gas turbine engine combustor. The liner material is heat-resistant steel with relatively low heat conductivity. To accommodate outside wall forced air cooling, the liner is designed to be thin, which unfortunately facilitates the possibility of high-amplitude wall vibrations (and failure due to fatigue) in case of pressure fluctuations in the combustor. The latter may occur due to a possible occurrence of a feedback loop between the aerodynamics, the combustion, the acoustics, and the structural vibrations. The structural vibrations act as a source of acoustic emitting the acoustic waves to the confined fluid. This leads to amplification in the acoustic filed and hence the magnitude of instability in the system. The aim of this paper is to explore the mechanism of fluid–structure interaction (FSI) on the LIMOUSINE setup which leads to limit cycle of pressure oscillations (LCO). Computational fluid dynamics (CFD) analysis using a RANS approach is performed to obtain the thermal and mechanical loading of the combustor liner, and finite element model (FEM) renders the temperature, stress distribution, and deformation in the liner. Results are compared to other numerical approaches like zero-way interaction and conjugated heat transfer model (CHT). To recognize the advantage/disadvantage of each method, validation is made with the available measured data for the pressure and vibration signals, showing that the thermoacoustic instabilities are well predicted using the CHT and two-way coupled approaches, while the zero-way interaction model prediction gives the largest discrepancy from experimental results.

Fluid Structure Interactions for Blast Wave Mitigation

2011 ◽  
Vol 78 (3) ◽  
Author(s):  
Wen Peng ◽  
Zhaoyan Zhang ◽  
George Gogos ◽  
George Gazonas
Keyword(s):  
Shock Wave ◽  
Blast Wave ◽  
Fluid Structure Interaction ◽  
Wave Formation ◽  
Plate Motion ◽  
Fluid Structure Interactions ◽  
Free Standing ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Shock Wave Formation

The dynamic response of a free-standing plate subjected to a blast wave is studied numerically to investigate the effects of fluid-structure interaction (FSI) in blast wave mitigation. Previous work on the FSI between a blast wave and a free-standing plate (Kambouchev, N., et al., 2006, “Nonlinear Compressibility Effects in Fluid-Structure Interaction and Their Implications on the Air-Blast Loading of Structures,” J. Appl. Phys., 100(6), p. 063519) has assumed a constant atmospheric pressure at the back of the plate and neglected the resistance caused by the shock wave formation due to the receding motion of the plate. This paper develops an FSI model that includes the resistance caused by the shock wave formation at the back of the plate. The numerical results show that the resistance to the plate motion is especially pronounced for a light plate, and as a result, the previous work overpredicts the mitigation effects of FSI. Therefore, the effects of the interaction between the plate and the shock wave formation at the back of the plate should be considered in blast wave mitigation.

Aerodynamic Damping and Fluid-Structure Interaction of Blast Loaded Flexible Structures

2011 ◽  
Vol 82 ◽  
pp. 491-496
Author(s):  
Martien Teich ◽  
Norbert Gebbeken ◽  
Martin Larcher
Keyword(s):  
Dynamic Response ◽  
Fluid Structure Interaction ◽  
Flexible Structures ◽  
Blast Loads ◽  
Damping Term ◽  
Damping Force ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Aerodynamic Damping ◽  
Compliant Systems

This paper analyses the e ects of air-structure interaction of systems subjectedto weak blast loads. While these coupling e ects are negligible for typical steel or concretestructures, they may dominate the dynamic response of lighter and more exible (compliant)systems like membranes, blast curtains or cable facades. For these light and exible systems,a classical decoupled analysis, i.e., neglecting the inuence of the surrounding air, might sig-ni cantly overestimate the deections and strains. However, we show that the coupling e ectscan be accounted for by basically adding a viscous aerodynamic damping force. We discussand compare two approaches how to obtain the aerodynamic damping term. With decreasingstructural sti ness and mass, the damping contribution of air increases signi cantly. The resultsof Hydrocode simulations are presented, and an outlook into further areas of research is given.

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