检索结果-内蒙古大学图书馆

Partitioned solution strategies for coupled BEM-FEM acoustic fluid-structure interaction problems

COMPUTERS & structureS 2015年 152卷 45-58页

作者： Rodriguez-Tembleque, Luis Gonzalez, Jose A. Cerrato, Antonio Univ Seville Escuela Tecn Super Ingn E-41092 Seville Spain

This paper investigates two FEM-BEM coupling formulations for acoustic fluid-structure interaction (FSI) problems, using the Finite Element Method (FEM) to model the structure and the Boundary Element Method (BEM) to represent a linear acoustic fluid. The coupling methods described interconnect fluid and structure using classical or localized Lagrange multipliers, allowing the connection of non-matching interfaces. First coupling technique is the well known mortar method, that uses classical multipliers and is compared with a new formulation of the method of localized Lagrange multipliers (LLM) for PSI applications with non-matching interfaces. The proposed non-overlapping domain decomposition technique uses a classical non-symmetrical acoustic BEM formulation for the fluid, although a symmetric GalerIcin BEM formulation could be used as well. A comparison between the localized methodology and the mortar method in highly non conforming interface meshes is presented. Furthermore, the methodology proposes an iterative preconditioned and projected bi-conjugate gradient solver which presents very good scalability properties in the solution of this kind of problems. (C) 2015 Elsevier Ltd. All rights reserved.

关键词： Domain decomposition FETI BETI fluid-structure interaction Localized Lagrange multipliers Mortar

来源：评论

学校读者我要写书评

暂无评论

Multiscale fluid-structure interaction modelling to determine the mechanical stimulation of bone cells in a tissue engineered scaffold

引用

BIOMECHANICS AND MODELING IN MECHANOBIOLOGY 2015年第2期14卷 231-243页

作者： Zhao, Feihu Vaughan, Ted J. Mcnamara, Laoise M. Natl Univ Ireland Coll Engn & Informat Biomechan Res Ctr BMEC Biomed Engn Galway Ireland

Recent studies have shown that mechanical stimulation, by means of flow perfusion and mechanical compression (or stretching), enhances osteogenic differentiation of mesenchymal stem cells and bone cells within biomaterial scaffolds in vitro. However, the precise mechanisms by which such stimulation enhances bone regeneration is not yet fully understood. Previous computational studies have sought to characterise the mechanical stimulation on cells within biomaterial scaffolds using either computational fluid dynamics or finite element (FE) approaches. However, the physical environment within a scaffold under perfusion is extremely complex and requires a multiscale and multiphysics approach to study the mechanical stimulation of cells. In this study, we seek to determine the mechanical stimulation of osteoblasts seeded in a biomaterial scaffold under flow perfusion and mechanical compression using multiscale modelling by two-way fluid-structure interaction and FE approaches. The mechanical stimulation, in terms of wall shear stress (WSS) and strain in osteoblasts, is quantified at different locations within the scaffold for cells of different attachment morphologies (attached, bridged). The results show that 75.4 % of scaffold surface has a WSS of 0.1-10 mPa, which indicates the likelihood of bone cell differentiation at these locations. For attached and bridged osteoblasts, the maximum strains are 397 and 177,200 , respectively. Additionally, the results from mechanical compression show that attached cells are more stimulated ( ) than bridged cells ( ). Such information is important for understanding the biological response of osteoblasts under in vitro stimulation. Finally, a combination of perfusion and compression of a tissue engineering scaffold is suggested for osteogenic differentiation.

关键词： fluid-structure interaction Multiscale modelling Osteoblast Tissue engineered scaffold

来源：评论

学校读者我要写书评

暂无评论

A matrix free, partitioned solution of fluid-structure interaction problems using finite volume and finite element methods

引用

EUROPEAN JOURNAL OF MECHANICS B-fluidS 2015年第PartA期49卷 272-286页

作者： Suliman, R. Oxtoby, O. F. Malan, A. G. Kok, S. CSIR ZA-0002 Pretoria South Africa Univ Pretoria Dept Mech & Aeronaut Engn ZA-0002 Pretoria South Africa Univ Cape Town Dept Mech Engn ZA-7700 Cape Town South Africa

A fully-coupled partitioned finite volume-finite volume and hybrid finite volume-finite element fluid-structure interaction scheme is presented. The fluid domain is modelled as a viscous incompressible isothermal region governed by the Navier-Stokes equations and discretised using an edge-based hybrid-unstructured vertex-centred finite volume methodology. The structure, consisting of a homogeneous isotropic elastic solid undergoing large, non-linear deformations, is discretised using either an elemental/nodal-strain finite volume approach or isoparametric Q8 finite elements and is solved using a matrix-free dual-timestepping approach. Coupling is on the solver sub-iteration level leading to a tighter coupling than if the subdomains are converged separately. The solver is parallelised for distributed-memory systems using METIS for domain-decomposition and MPI for inter-domain communication. The developed technology is evaluated by application to benchmark problems for strongly-coupled fluid-structure interaction systems. It is demonstrated that the scheme results in full coupling between the fluid and solid domains, whilst furnishing accurate solutions. (C) 2014 Elsevier Masson SAS. All rights reserved.

关键词： fluid-structure interaction Partitioned solution Arbitrary Lagrangian-Eulerian (ALE) Finite volume methods Finite element methods Parallelisation

来源：评论

学校读者我要写书评

暂无评论

An immersogeometric variational framework for fluid-structure interaction: Application to bioprosthetic heart valves

引用

COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING 2015年 284卷 1005-1053页

作者： Kamensky, David Hsu, Ming-Chen Schillinger, Dominik Evans, John A. Aggarwal, Ankush Bazilevs, Yuri Sacks, Michael S. Hughes, Thomas J. R. Univ Texas Austin Inst Computat Engn & Sci Ctr Cardiovasc Simulat Austin TX 78712 USA Iowa State Univ Dept Mech Engn Ames IA 50011 USA Univ Minnesota Dept Civil Engn Minneapolis MN 55455 USA Univ Colorado Dept Aerosp Engn Sci Boulder CO 80309 USA Univ Calif San Diego Dept Struct Engn La Jolla CA 92093 USA

In this paper, we develop a geometrically flexible technique for computational fluid-structure interaction (FSI). The motivating application is the simulation of tri-leaflet bioprosthetic heart valve function over the complete cardiac cycle. Due to the complex motion of the heart valve leaflets, the fluid domain undergoes large deformations, including changes of topology. The proposed method directly analyzes a spline-based surface representation of the structure by immersing it into a non-boundary-fitted discretization of the surrounding fluid domain. This places our method within an emerging class of computational techniques that aim to capture geometry on non-boundary-fitted analysis meshes. We introduce the term "immersogeometric analysis" to identify this paradigm. The framework starts with an augmented Lagrangian formulation for FSI that enforces kinematic constraints with a combination of Lagrange multipliers and penalty forces. For immersed volumetric objects, we formally eliminate the multiplier field by substituting a fluid-structure interface traction, arriving at Nitsche's method for enforcing Dirichlet boundary conditions on object surfaces. For immersed thin shell structures modeled geometrically as surfaces, the tractions from opposite sides cancel due to the continuity of the background fluid solution space, leaving a penalty method. Application to a bioprosthetic heart valve, where there is a large pressure jump across the leaflets, reveals shortcomings of the penalty approach. To counteract steep pressure gradients through the structure without the conditioning problems that accompany strong penalty forces, we resurrect the Lagrange multiplier field. Further, since the fluid discretization is not tailored to the structure geometry, there is a significant error in the approximation of pressure discontinuities across the shell. This error becomes especially troublesome in residual-based stabilized methods for incompressible flow, leading to problemat

关键词： fluid-structure interaction Bioprosthetic heart valve Immersogeometric analysis Isogeometric analysis Nitsche's method Weakly enforced boundary conditions

来源：评论

学校读者我要写书评

暂无评论

A non-intrusive partitioned approach to couple smoothed particle hydrodynamics and finite element methods for transient fluid-structure interaction problems with large interface motion

引用

COMPUTATIONAL MECHANICS 2015年第4期55卷 697-718页

作者： Li, Zhe Leduc, Julien Nunez-Ramirez, Jorge Combescure, Alain Marongiu, Jean-Christophe Ecole Cent Lyon Lab Mecan Fluides & Acoust F-69134 Ecully France ANDRITZ Hydro F-69100 Villeurbanne France INSA Lyon Lab Mecan Contacts & Struct F-69621 Villeurbanne France

We propose a non-intrusive numerical coupling method for transient fluid-structure interaction (FSI) problems simulated by means of different discretization methods: smoothed particle hydrodynamics (SPH) and finite element (FE) methods for the fluid and the solid sub-domains, respectively. As a partitioned coupling method, the present algorithm can ensure a zero interface energy during the whole period of numerical simulation, even in the presence of large interface motion. In other words, the time integrations of the two sub-domains (second order Runge-Kutta scheme for fluid and Newmark integrator for solid) are synchronized. Thanks to this energy-conserving feature, one can preserve the minimal order of accuracy in time and the numerical stability of the FSI simulations, which are validated with a 1D and a 2D trivial numerical test cases. Additionally, some other 2D FSI simulations involving large interface motion have also been carried out with the proposed SPH-FE coupling method. Finally, an example of aquaplaning problem is given in order to show the feasibility of such coupling method in multi-dimensional applications with complicated structural geometries.

关键词： Coupling of SPH-FE methods Interface-energy conserving fluid-structure interaction Large interface motion Transient analysis

来源：评论

学校读者我要写书评

暂无评论

Analysis of hydraulic fracturing in concrete dam considering fluid-structure interaction using XFEM-FVM model

引用

ENGINEERING FAILURE ANALYSIS 2015年 57卷 399-412页

作者： Wang, Kefeng Zhang, Qing Xia, Xiaozhou Wang, Lei Liu, Xuecong Hohai Univ Dept Engn Mech Nanjing 210098 Jiangsu Peoples R China

High-pressure hydraulic fracturing (HF) of cracks is the crucial factor in the safety-assessment of high concrete dams, and fluid-structure interaction in HF is the key to accurately calculate the fluid pressure within cracks. In this study, a hybrid approach combining the extended finite element method (XFEM) and the finite volume method (FVM) is introduced to simulate HF in concrete dams. Through the hybrid approach XFEM-FVM, we can obtain water pressure distribution within cracks, which reflects the coupling relationship between water pressure and fracture width. This approach is verified by an example, and the numerical results agree well with the corresponding analytic solutions. Then, we use it to simulate the HF in a concrete gravity dam. Results show that, in contrast to the constant water pressure distribution within cracks, the distribution calculated by XFEM-FVM varies with time and leads to the bigger crack extension angle, contrary to growth length. It also illustrates the significance of considering fluid-structure interaction in HF progress. This study reveals that the approach is a very efficient tool for HF simulation in concrete dam. (C) 2015 Elsevier Ltd. All rights reserved.

关键词： fluid-structure interaction Gravity dam Hydraulic fracturing XFEM FVM Crack growth

来源：评论

学校读者我要写书评

暂无评论

Uniform stabilization to equilibrium of a nonlinear fluid-structure interaction model

引用

NONLINEAR ANALYSIS-REAL WORLD APPLICATIONS 2015年 25卷 51-63页

作者： Lu, Yongjin Virginia State Univ Dept Math & Econ Petersburg VA 23806 USA

We consider uniform stability to a nontrivial equilibrium of a nonlinear fluid-structure interaction (FSI) defined on a two or three dimensional bounded domain. Stabilization is achieved via boundary and/or interior feedback controls implemented on both the fluid and the structure. The interior damping on the fluid combining with the viscosity effect stabilizes the dynamics of fluid. However, this dissipation propagated from the fluid alone is not sufficient to drive uniformly to equilibrium the entire coupled system. Therefore, additional interior damping on the wave component or boundary porous like damping on the interface is considered. A geometric condition on the interface is needed if only boundary damping on the wave is active. The main technical difficulty is the mismatch of regularity of hyperbolic and parabolic component of the coupled system. This is overcome by considering special multipliers constructed from Stokes solvers. The uniform stabilization result obtained in this article is global for the fully coupled FSI model. (C) 2015 Elsevier Ltd. All rights reserved.

关键词： fluid-structure interaction Navier-Stokes equation Wave equation Boundary feedback control Interior feedback control Uniform stability

来源：评论

学校读者我要写书评

暂无评论

An embedded strategy for the analysis of fluid structure interaction problems

引用

COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING 2016年 300卷 106-128页

作者： Costarelli, Santiago D. Garelli, Luciano Cruchaga, Marcela A. Storti, Mario A. Ausensi, Ronald Idelsohn, Sergio R. CONICET UNL CIMEC Ctr Invest Metodos Computac Santa Fe Argentina UN Litoral Fac Ingn Ciencias Hidr Santa Fe Argentina Univ Santiago Chile USACH Dept Ingn Mecan Santiago Chile ICREA Barcelona Spain Tech Univ Catalonia UPC Int Ctr Numer Methods Engn CIMNE Gran Capitan S-N Barcelona 08034 Spain

A Navier-Stokes solver based on Cartesian structured finite volume discretization with embedded bodies is presented. fluid structure interaction with solid bodies is performed with an explicit partitioned strategy. The Navier-Stokes equations are solved in the whole domain via a Semi-Implicit Method for Pressure Linked Equations (SIMPLE) using a colocated finite volume scheme, stabilized via the Rhie-Chow discretization. As uniform Cartesian grids are used, the solid interface usually do not coincide with the mesh, and then a second order Immersed Boundary Method is proposed, in order to avoid the loss of precision due to the staircase representation of the surface. This fact also affects the computation of fluid forces on the solid wall and, accordingly, the results in the fluid-structure analysis. In the present work, first and second order approximations for computing the fluid forces at the interface are studied and compared. The solver is specially oriented to General Purpose Graphic Processing Units (GPGPU) hardware and the efficiency is discussed. Moreover, a novel submerged buoy experiment is also reported. The experiment consists of a sphere with positive buoyancy fully submerged in a cubic tank, subject to harmonic displacements imposed by a shake table. The sphere is attached to the bottom of the tank with a string. The position of the buoy is determined from video records with a Motion Capture algorithm. The obtained amplitude and phase curves allow a precise determination of the added mass and drag forces. Due to this aspect the experimental data can be of interest for comparison with other fluid-structure interaction codes. Finally, the numerical results are compared with the experiments, and allow the confirmation of the numerically predicted drag and added mass of the body. (C) 2015 Elsevier B.V. All rights reserved.

关键词： Graphics Processing Units Incompressible Navier-Stokes Embedded methods Added mass fluid-structure interaction Fully submerged buoy experiments

来源：评论

学校读者我要写书评

暂无评论

Numerical evaluation of blood viscosity affecting pulse wave propagation in a fluid-structure interaction model

引用

BIOMEDICAL ENGINEERING-BIOMEDIZINISCHE TECHNIK 2015年第1期60卷 11-15页

作者： He, Fan Hua, Lu Gao, Li-jian Beijing Univ Civil Engn & Architecture Sch Sci Dept Mech Beijing 100044 Peoples R China Chinese Acad Med Sci Fuwai Hosp Natl Ctr Cardiovasc Dis Key Lab Clin Trial Res Cardiovasc DrugsMinist Hl Beijing 100037 Peoples R China Peking Union Med Coll Beijing 100037 Peoples R China

High blood viscosity often causes cardiovascular diseases, such as hypertension, atherosclerosis and thrombosis. It is proven that blood viscosity plays an important role in cardiovascular functions. In this paper, pulse wave characteristics with normal and high blood viscosities are presented in detail to evaluate how blood viscosity affects pulse wave propagation. A fluid-structure interaction is employed to solve for pulse wave characteristics. The results show that increased blood viscosity does not change the time delay of wave propagation. However, high viscosity reduces the velocity amplitude, while it enhances the pressure level. This study provides physical insight for evaluating blood viscosity leading potentially to pulse wave changes.

关键词： blood viscosity finite element method fluid-structure interaction pulse wave propagation

来源：评论

学校读者我要写书评

暂无评论

Investigation of material modeling in fluid-structure interaction analysis of an idealized three-layered abdominal aorta: aneurysm initiation and fully developed aneurysms

引用

JOURNAL OF BIOLOGICAL PHYSICS 2015年第2期41卷 173-201页

作者： Simsek, Fatma Gulden Kwon, Young W. Bogazici Univ Inst Biomed Engn Istanbul Turkey Naval Postgrad Sch Dept Mech & Aerosp Engn Monterey CA 93943 USA

Different material models for an idealized three-layered abdominal aorta are compared using computational techniques to study aneurysm initiation and fully developed aneurysms. The computational model includes fluid-structure interaction (FSI) between the blood vessel and the blood. In order to model aneurysm initiation, the medial region was degenerated to mimic the medial loss occurring in the inception of an aneurysm. Various cases are considered in order to understand their effects on the initiation of an abdominal aortic aneurysm. The layers of the blood vessel were modeled using either linear elastic materials or Mooney-Rivlin (otherwise known as hyperelastic) type materials. The degenerated medial region was also modeled in either linear elastic or hyperelastic-type materials and assumed to be in the shape of an arc with a thin width or a circular ring with different widths. The blood viscosity effect was also considered in the initiation mechanism. In addition, dynamic analysis of the blood vessel was performed without interaction with the blood flow by applying time-dependent pressure inside the lumen in a three-layered abdominal aorta. The stresses, strains, and displacements were compared for a healthy aorta, an initiated aneurysm and a fully developed aneurysm. The study shows that the material modeling of the vessel has a sizable effect on aneurysm initiation and fully developed aneurysms. Different material modeling of degeneration regions also affects the stress-strain response of aneurysm initiation. Additionally, the structural analysis without considering FSI (called noFSI) overestimates the peak von Mises stress by 52% at the interfaces of the layers.

关键词： Three-layered wall fluid-structure interaction Abdominal aorta Wall stresses and strains

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：