On the Role of Fluid–Structure Interaction on Structural Loading by Pressure Waves in Air

2018 ◽  
Vol 85 (11) ◽  
Author(s):  
Hannes L. Gauch ◽  
Francesco Montomoli ◽  
Vito L. Tagarielli

This study investigates the significance of fluid–structure interaction (FSI) effects on structural response to pressure wave and shock wave loading. Finite element (FE) simulations and one-dimensional (1D) analytical models are used to compare the responses of simple structures in presence and absence of FSI. Results are provided in nondimensional form and allow rapid estimation of the significance of FSI. The cases of a square elastic plate in bending and a square rigid-perfectly plastic plate undergoing membrane stretching are discussed in detail. We deduce simple formulae to identify scenarios in which effects of FSI can be neglected.

Fluids ◽  
2021 ◽  
Vol 6 (3) ◽  
pp. 95
Author(s):  
Stéphane Vincent ◽  
Jean-Paul Caltagirone

The unification of the laws of fluid and solid mechanics is achieved on the basis of the concepts of discrete mechanics and the principles of equivalence and relativity, but also the Helmholtz–Hodge decomposition where a vector is written as the sum of divergence-free and curl-free components. The derived equation of motion translates the conservation of acceleration over a segment, that of the intrinsic acceleration of the material medium and the sum of the accelerations applied to it. The scalar and vector potentials of the acceleration, which are the compression and shear energies, give the discrete equation of motion the role of conservation law for total mechanical energy. Velocity and displacement are obtained using an incremental time process from acceleration. After a description of the main stages of the derivation of the equation of motion, unique for the fluid and the solid, the cases of couplings in simple shear and uniaxial compression of two media, fluid and solid, make it possible to show the role of discrete operators and to find the theoretical results. The application of the formulation is then extended to a classical validation case in fluid–structure interaction.


2016 ◽  
Vol 08 (08) ◽  
pp. 1650095 ◽  
Author(s):  
H. Devaraj ◽  
Kean C. Aw ◽  
E. Haemmerle ◽  
R. Sharma

3D printed hair-like micro-structures have been previously demonstrated in a novel micro-fluidic flow sensor aimed at sensing air flows down to rates of a few milliliters per second. However, there is a lack of in-depth understanding of the structural response of these ‘micro-hairs' under a fluid flow field. This paper demonstrates the use of lattice Boltzmann methods (LBM) to understand this structural response towards a better optimization of the micro-hair flow sensors designed to suit the end applications' needs. The LBM approach was chosen as an efficient alternative to simulate Navier–Stokes equations for modeling fluid flow around complex geometries primarily for improved accuracy and simplicity with lesser computational costs. As the spatial dimensions of the sensor's flow channel are much larger in comparison to the actual micro-hairs (the sensing element), a multidimensional approach of combining two-dimensional (D2Q9) and three-dimensional (D3Q19) lattice configurations were implemented for improved computational speeds and efficiency. The drag force on the micro-hairs was estimated using the momentum-exchange method in the D3Q19 configuration and this drag force is transferred to the structural analysis model which determines the micro-hair deformation using Euler–Bernoulli beam theory. The entirety of the LBM Fluid–Structure Interaction (FSI) model was implemented within MATLAB and the obtained results are compared against the numerical model implemented on a commercially available software package.


2009 ◽  
Vol 46 (1) ◽  
pp. 43-52 ◽  
Author(s):  
Ryo Torii ◽  
Marie Oshima ◽  
Toshio Kobayashi ◽  
Kiyoshi Takagi ◽  
Tayfun E. Tezduyar

Author(s):  
Se Yun Hwang ◽  
Jang Hyun Lee ◽  
Sung Chan Kim ◽  
In Sik Nho ◽  
Beom Seon Jang ◽  
...  

Sloshing assessment of LNG cargo tanks is expected to satisfy the required structural strength of insulation components. It is difficult to estimate the sloshing pressure and structural response of cargo containment in real size because of the uncertainty of intensive computation time as well as the complexity of sloshing motion. In this study, several procedural components are suggested to meet the endurable strength of LNG CCS during the design of LNG cargo containment. The measured sloshing impacts from small scale model test are treated by individual impacts. Thereafter, static and transient structural response of LNG CCS is sequentially performed in order to evaluate the structural strength. The structural response is also calculated in time series through convolution method considering the history of pressure. It is used to investigate the structural response induced by the history of impacts. Finally, an idealized fluid structure interaction on the localized insulation panel is investigated in order to evaluate the structural strength in actual scale.


2019 ◽  
Vol 92 (2) ◽  
pp. 129-147 ◽  
Author(s):  
Andrea La Spina ◽  
Christiane Förster ◽  
Martin Kronbichler ◽  
Wolfgang A. Wall

2021 ◽  
Vol 9 (4) ◽  
pp. 400
Author(s):  
Donghan Woo ◽  
Jung Kwan Seo

Fire accidents on ships and offshore structures lead to complex non-linear material and geometric behavior, which can cause structural collapse. This not only results in significant casualties, but also environmental catastrophes such as oil spills. Thus, for the fire safety design of structures, precise prediction of the structural response to fire using numerical and/or experimental methods is essential. This study aimed to validate the two-way fluid-structure interaction (FSI) method for predicting the non-linear structural response of H-beams to a propane burner fire by comparison with experimental results. To determine the interaction between a fire simulation and structural analysis, the Fire-Thermomechanical Interface model was introduced. The Fire Dynamics Simulator and ANSYS Parametric Design Language were used for computational fluid dynamics and the finite element method, respectively. This study validated the two-way FSI method for precisely predicting the non-linear structural response of H-beams to a propane burner fire and proposed the proper time increment for two-way FSI analysis.


2021 ◽  
Author(s):  
Erick Johnson ◽  
Ryan Schwab ◽  
Mark Jankauski

Flapping, flexible insect wings deform during flight from aerodynamic and inertial forces. This deformation is believed to enhance aerodynamic and energetic performance. However, the predictive models used to describe flapping wing fluid-structure interaction (FSI) often rely on high fidelity computational solvers such as computational fluid dynamics (CFD) and finite element analysis (FEA). Such models require lengthy solution times and may obscure the physical insights available to analytical models. In this work, we develop a reduced order model (ROM) of a wing experiencing single-degree-of-freedom flapping. The ROM is based on deformable blade element theory and the assumed mode method. We compare the ROM to a high-fidelity CFD/FEA model and a simple experiment comprised of a mechanical flapper actuating a paper wing. Across a range of flapping-to-natural frequency ratios relevant to flying insects, the ROM predicts wingtip deflection five orders of magnitude faster than the CFD/FEA model. Both models are resolved to predict wingtip deflection within 30% of experimentally measured values. The ROM is then used to identify how the physical forces acting on the wing scale relative to one another. We show that, in addition to inertial and aerodynamic forces, added mass and aerodynamic damping influence wing deformation nontrivially.


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