scholarly journals The impact of vertical human-structure interaction on the response of footbridges to pedestrian excitation

2017 ◽  
Vol 402 ◽  
pp. 104-121 ◽  
Author(s):  
K. Van Nimmen ◽  
G. Lombaert ◽  
G. De Roeck ◽  
P. Van den Broeck
Keyword(s):  
Structure Interaction ◽  
The Impact ◽  
Pedestrian Excitation

Entrapping an impacting particle at a liquid–gas interface

2018 ◽  
Vol 841 ◽  
pp. 1073-1084 ◽  
Author(s):  
Han Chen ◽  
Hao-Ran Liu ◽  
Xi-Yun Lu ◽  
Hang Ding
Keyword(s):  
Immersed Boundary Method ◽  
Density Ratio ◽  
Liquid Pool ◽  
Diffuse Interface ◽  
Critical Conditions ◽  
Immersed Boundary ◽  
Structure Interaction ◽  
Scaling Models ◽  
The Impact

We numerically investigate the mechanism leading to the entrapment of spheres at the gas–liquid interface after impact. Upon impact onto a liquid pool, a hydrophobic sphere is seen to follow one of the three regimes identified in the experiment (Lee & Kim, Langmuir, vol. 24, 2008, pp. 142–145): sinking, bouncing or being entrapped at the interface. It is important to understand the role of wettability in this process of flow–structure interaction with dynamic wetting, and in particular, to what extent the wettability can determine whether the sphere is entrapped at the interface. For this purpose, a diffuse-interface immersed boundary method is adopted in the numerical simulations. We expand the parameter space considered previously, provide the phase diagrams and identify the key phenomena in the impact dynamics. Then, we propose the scaling models to interpret the critical conditions for the occurrence of sphere entrapment, accounting for the wettability of the sphere. The models are shown to provide a good correlation among the impact inertia of the drop, the surface tension, the wettability and the density ratio of the sphere to the liquid.

Impact of E-Services Quality on E-Loyalty in Paltel E-Satisfaction as a Mediating Variable

2020 ◽  
Vol 12 (2) ◽  
pp. 81-101
Author(s):  
Maan Ali Alkhateeb
Keyword(s):  
Service Quality ◽  
Quantitative Research ◽  
Services Quality ◽  
Customer Retention ◽  
Research Approach ◽  
Content Structure ◽  
Structure Interaction ◽  
Independent Variable ◽  
Security And Reliability ◽  
The Impact

E-loyalty has received great interest from researchers as a key element for customer retention and the growth of firms as well as gaining new customers. This study aims to investigate the impact of the electronic website services quality on e-loyalty in the companies listed within Paltel using electronic satisfaction as a mediating variable. Seven dimensions of e-service quality are examined including content, structure, interaction, presentation, responsiveness, e-security, and reliability. The quantitative research approach is conducted on the returned 393 valid surveys. The findings revealed and emphasized the role played by e-satisfaction as a mediating variable between the independent variable's dimensions and the independent variable.

Explicit Finite Element Study of Liquid Sloshing Behavior in Fluid-Structure Interaction Condition

2017 ◽  
Author(s):  
Shuo Yang ◽  
Raymond K. Yee
Keyword(s):  
Finite Element ◽  
Water Level ◽  
Similarity Theory ◽  
Fluid Structure Interaction ◽  
Water Levels ◽  
Tank Wall ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Sloshing Phenomenon ◽  
The Impact

As a common phenomenon in liquid motions, sloshing usually happens in a partially filled liquid tank of moving vehicle or structure. The objectives of this paper are to study sloshing behavior in rigid tank and deformable tank, and to develop a better performance baffle design in the tank under seismic excitations. The tank is surged with a sinusoidal oscillation about horizontal x-direction. The hydro-elasticity effect of sloshing pressure on the tank wall was taken into consideration due to the fluid-structure interaction between impact pressures and tank structures. ABAQUS finite element program using Coupled Eulerian-Lagrangian (CEL) technique was employed to simulate fluid sloshing. The sloshing phenomenon was studied in rigid tank and deformable tank models with three different water levels, and the effect of wall thickness of the deformable tank on sloshing behavior was discussed. One way to minimize the effect of sloshing in a tank, baffles are used and installed in the middle of the tank, and then various heights and material types of baffle were evaluated. The simulation results show that higher water level case creates greater pressure impact on the tank wall than lower water level case, and the elasticity of the tank structure would reduce the impact pressure of the wall. For the simulation tank model with size of 1m (H) × 1m (W) × 0.2m (D), better performance baffle was found to be the one with the height of 0.35m and was made of acrylic material. Moreover, the conclusion of this study can be extrapolated to other dimensions of the model based on similarity theory. This paper also can serve as an aid in further studying sloshing phenomenon. The findings of this study can be applied to restrain or minimize sloshing motions inside a tank.

Simulation of Thermal Fluid-Structure Interaction in Blade-Disc Configuration of an Aircraft Turbine Model

2014 ◽  
Author(s):  
Hannes Lück ◽  
Michael Schäfer ◽  
Heinz-Peter Schiffer
Keyword(s):  
Fluid Structure Interaction ◽  
Labyrinth Seal ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Sector Model ◽  
Implicit Approach ◽  
Coupling Approach ◽  
Disc Configuration ◽  
State Mixing ◽  
The Impact

This paper describes the impact of structural deformations on interstage cavity flow dynamics by adopting thermal fluid-structure interaction methods. These coupled numerical approaches solve the fluid-solid heat transfer in conjunction with the geometrical deformation due to mismatched centrifugal and thermal expansion of rotating and stationary turbine discs. Especially the changing clearances at the interstage labyrinth seal, at the rotor blade tips and at the rotor stator rim seals can be captured to calculate the correct flow physics at these locations. A manual explicit coupling approach in ANSYS is utilized that couples the CFX CHT solver with the FE solver Mechanical. The validation of a 3D sector model with experimental data shows improvements in predicting the metal temperature of the rotating walls but also disclose problems with the overheated stationary parts, mainly due to the utilization of steady state mixing planes. Additionally, a surrogate 2D model of the 3D model is introduced to compare the explicit coupling approach with an implicit approach exploiting the ANSYS MFX interface between the fluid and the solid domain. Thereby, the manual coupling approach reveals to be much more efficient for the examined thermal fluid-structure interaction.

scholarly journals Modal Analysis of the Ice-Structure Interaction Problem

2008 ◽  
Author(s):  
Michael A. Venturella ◽  
Mayuresh J. Patil ◽  
Leigh S. McCue
Keyword(s):  
Modal Analysis ◽  
Interaction Model ◽  
Primary Response ◽  
System Response ◽  
Structure Interaction ◽  
Ice Accumulation ◽  
Vibration Modal ◽  
Future Work ◽  
The Impact ◽  
Interaction Problem

In this paper the authors build upon the single degree of freedom ice-structure interaction model initially proposed by Matlock, et al. (1969, 1971). The model created by Matlock, et al. (1969, 1971), assumed that the primary response of the structure would be in its fundamental mode of vibration. Modal analysis is used in this study, in which the response of each mode is superposed to find the complete modal response of the entire length of a pier subject to incremental ice loading. In Matlock, et al., the physical system is a bottom supported pier modeled as a cantilever beam. Realistic conditions such as ice accumulation on the pier modeled as a point mass and uncertainties in the ice characteristics are introduced in order to provide a stochastic response. The impact of number of modes in modeling is studied as well as dynamics due to fluctuations of ice impact height as a result of typical tidal fluctuations. A Poincare´ based analysis following on the research of Karr, et al. (1992) is employed to identify and periodic behavior of the system response. The intention of this work is to provide a foundation for future work coupling multiple piers and connecting structure for a comprehensive ice-wind-structural dynamics model.

scholarly journals Wave Propagation Across Solid-Fluid Interface With Fluid-Structure Interaction

2015 ◽  
Author(s):  
Tomohisa Kojima ◽  
Kazuaki Inaba ◽  
Kosuke Takahashi
Keyword(s):  
Wave Propagation ◽  
Theoretical Model ◽  
Characteristic Impedance ◽  
Fluid Structure Interaction ◽  
Fluid Interface ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Mechanism Of Wave Propagation ◽  
Free Falling ◽  
The Impact

This paper reports on investigations conducted with a view towards developing a theoretical model for wave propagation across solid-fluid interfaces with fluid-structure interaction. Although many studies have been conducted, the mechanism of wave propagation close to the solid-fluid interface remains unclear. Consequently, our aim is to clarify the mechanism of wave propagation across the solid-fluid interface with fluid-structure interaction and develop a theoretical model to explain this phenomenon. In experiments conducted to develop the theory, a free-falling steel projectile is used to impact the top of a solid buffer placed immediately above the surface of water within a polycarbonate tube. The stress waves created as a result of the impact of the projectile propagated through the buffer and reached the interface of the buffer and water (fluid) in the tube. Two different buffers (polycarbonate and aluminum) were used to examine the interaction effects. The results of the experiments indicated that the amplitude of the interface pressure increased in accordance with the characteristic impedance of the solid medium. This cannot be explained by the classical theory of wave reflection and transmission. Thus, it is clear that on the solid-fluid interface with fluid-structure interaction, classical theories alone cannot precisely predict the generated pressure.

Modelling the source of glacial earthquakes for a better understanding of the impact of iceberg capsize on glacier stability

2020 ◽  
Author(s):  
Pauline Bonnet ◽  
Vladislav Yastrebov ◽  
Alban Leroyer ◽  
Patrick Queutey ◽  
Anne Mangeney ◽  
...  
Keyword(s):  
Mass Loss ◽  
Fluid Structure Interaction ◽  
Greenland Ice Sheet ◽  
Stick Slip ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Dynamic Mass ◽  
Glacier Terminus ◽  
Glacier Dynamics ◽  
The Impact

<p>One current concern in climate science is the estimations of the amount of ice loss by glaciers each year and the corresponding rate of sea level rise. Greenland ice sheet contribution is significant with about 30% to the global ice mass losses. Ice loss in Greenland is distributed approximately equally between loss in land by surface melting and loss at the front of marine-terminating glaciers that is modulated by dynamic processes. Dynamic mass loss includes both submarine melting and iceberg calving. The processes that control ablation at tidewater glacier termini, glacier retreat and calving are complex, setting the limits to the estimation of dynamic mass loss and the relation to glacier dynamics. It involves interactions between bedrock – glaciers – icebergs – ice-mélange – water – atmosphere. Moreover, the capsize of cubic kilometer scale icebergs close to a glacier front can destabilize the glacier, generate tsunami waves, and induce mixing of the water column which can impact both the local fauna and flora.</p><p>We aim to improve the understanding of iceberg capsize using a mechanical modeling of iceberg rotation against the glacier terminus, constrained by the generated seismic waves that are recorded at teleseismic distances. To achieve this objective, we develop a fluid-structure interaction model for the capsizing iceberg. Full scale fluid-structure interaction models enable accurate simulation of complex fluid flows in presence of rigid or deformable solids and in presence of free surfaces. However, such models are computationally very expensive. Therefore, our strategy is to construct a simple solid dynamics model involving contact and friction, whose simplified interaction with water is governed by parametrized forces and moments. We fine tune these parametrized effects on an iceberg capsizing in contact with a glacier with the help of reference direct numerical simulations of fluid-structure interactions involving full resolution of Navier-Stokes equations. We assess the sensitivity of the glacier dynamics to the glacier-bedrock friction law and the conditions for triggering a stick-slip motion of the glacier due to iceberg capsize. The seismogenic sources of the capsizing iceberg in contact with a glacier simulated with our model are then compared to the recorded seismic signals for well documented events.</p>

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