scholarly journals Development and analytical validation of a finite element model of fluid transport through osteochondral tissue

2020 ◽  
Author(s):  
Brady D. Hislop ◽  
Chelsea M. Heveran ◽  
Ronald K. June
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Fluid Transport ◽  
Fluid Pressure ◽  
Viscoelastic Model ◽  
Element Model ◽  
Pressure Gradients ◽  
Superficial Zone ◽  
Bone Interface ◽  
Osteochondral Tissue

AbstractFluid transport between cartilage and bone is critical to joint health. The objective of this study was to develop and analytically validate a finite element model of osteochondral tissue capable of modeling cartilage-bone fluid transport. A biphasic viscoelastic model using an ellipsoidal fiber distribution was created with three distinct layers of cartilage (superficial zone, middle zone, and deep zone) along with a layer of subchondral bone. For stress-relaxation in unconfined compression, our results for compressive stress, radial stress, effective fluid pressure, and elastic recoil were compared with established biphasic analytical solutions. Our model also shows the development of fluid pressure gradients at the cartilage-bone interface during loading. Fluid pressure gradients developed at the cartilage-bone interface with consistently higher pressures in cartilage following initial loading to 10% strain, followed by convergence towards equal pressures in cartilage and bone during the 400s relaxation period. These results provide additional evidence that fluid is transported between cartilage and bone during loading and improves upon estimates of the magnitude of this effect through incorporating a realistic distribution and estimate of the collagen ultrastructure. Understanding fluid transport between cartilage and bone may be key to new insights about the mechanical and biological environment of both tissues in health and disease.

A finite element model for evaluation of tibial prosthesis-bone interface in total knee replacement

1992 ◽  
Vol 25 (12) ◽  
pp. 1413-1424 ◽  
Author(s):  
R.L. Rakotomanana ◽  
P.F. Leyvraz ◽  
A. Curnier ◽  
J.H. Heegaard ◽  
P.J. Rubin
Keyword(s):  
Finite Element ◽  
Total Knee Replacement ◽  
Finite Element Model ◽  
Knee Replacement ◽  
Element Model ◽  
Bone Interface ◽  
Total Knee

BLOOD FLOW IN CORONARY ARTERY BIFURCATION CALCULATED BY TURBULENT FINITE ELEMENT MODEL

2021 ◽  
Author(s):  
Aleksandar Nikolić ◽  
◽  
Marko Topalović ◽  
Milan Blagojević ◽  
Vladimir Simić
Keyword(s):  
Finite Element ◽  
Blood Flow ◽  
Kinetic Energy ◽  
Finite Element Model ◽  
Fluid Velocity ◽  
Fluid Pressure ◽  
Element Model ◽  
Viscous Sublayer ◽  
Flow Problems ◽  
Analysis Of Results

Simulation of blood flow in this paper is analyzed using two-equation turbulent finite element model that can calculate values in the viscous sublayer. Implicit integration of the equations is used for determining the fluid velocity, fluid pressure, turbulence, kinetic energy, and dissipation of turbulent kinetic energy. These values are calculated in the finite element nodes for each step of incremental- iterative procedure. Developed turbulent finite element model, with the customized generation of finite element meshes, is used for calculating complex blood flow problems. Analysis of results showed that a cardiologist can use proposed tools and methods for investigating the hemodynamic conditions inside bifurcation of arteries.

Description and Validation of a Finite Element Model of Backflow During Infusion Into a Brain Tissue Phantom

2012 ◽  
Vol 8 (1) ◽  
Author(s):  
José J. García ◽  
Ana Belly Molano ◽  
Joshua H. Smith
Keyword(s):  
Finite Element ◽  
Hydraulic Conductivity ◽  
Finite Element Model ◽  
Brain Tissue ◽  
Nonlinear Boundary ◽  
Fluid Pressure ◽  
Element Model ◽  
Analytical Models ◽  
External Boundary ◽  
Forward Flow

An axisymmetric biphasic finite element model is proposed to simulate the backflow that develops around the external boundary of the catheter during flow-controlled infusions. The model includes both material and geometric nonlinearities and special treatments for the nonlinear boundary conditions used to represent the forward flow from the catheter tip and the axial backflow that occurs in the annular gap that develops as the porous medium detaches from the catheter. Specifically, a layer of elements with high hydraulic conductivity and low Young’s modulus was used to represent the nonlinear boundary condition for the forward flow, and another layer of elements with axial hydraulic conductivity consistent with Poiseuille flow was used to represent the backflow. Validation of the model was performed by modifying the elastic properties of the latter layer to fit published experimental values for the backflow length and maximum fluid pressure obtained during infusions into agarose gels undertaken with a 0.98-mm-radius catheter. Next, the finite element model predictions showed good agreement with independent experimental data obtained for 0.5-mm-radius and 0.33-mm-radius catheters. Compared to analytical models developed by others, this finite element model predicts a smaller backflow length, a larger fluid pressure, and a substantially larger percentage of forward flow. This latter difference can be explained by the important axial flow in the tissue that is not considered in the analytical models. These results may provide valuable guidelines to optimize protocols during future clinical studies. The model can be extended to describe infusions in brain tissue and in patient-specific geometries.

A 3D Biphasic Finite Element Model of the Human Knee Joint for the Study of Tibiofemoral Contact and Fluid Pressurization

2013 ◽  
Author(s):  
Hongqiang Guo ◽  
Suzanne A. Maher ◽  
Robert L. Spilker
Keyword(s):  
Finite Element ◽  
Fluid Flow ◽  
Knee Joint ◽  
Contact Problem ◽  
Finite Element Model ◽  
Soft Tissues ◽  
Fluid Pressure ◽  
Element Model ◽  
Human Knee Joint ◽  
Biphasic Finite Element

Biphasic theory which considers soft tissue, such as articular cartilage and meniscus, as a combination of a solid and a fluid phase has been widely used to model their biomechanical behavior [1]. Though fluid flow plays an important role in the load-carrying ability of soft tissues, most finite element models of the knee joint consider cartilage and the meniscus as solid. This simplification is due to the fact that biphasic contact is complicated to model. Beside the continuity conditions for displacement and traction that a single-phase contact problem consists of, there are two additional continuity conditions in the biphasic contact problem for relative fluid flow and fluid pressure [2]. The problem becomes even more complex when a joint is being modeled. The knee joint, for example, has multiple contact pairs which make the biphasic finite element model of this joint far more complex. Several biphasic models of the knee have been developed [3–9], yet simplifications were included in these models: (1) the 3D geometry of the knee was represented by a 2D axisymmetric geometry [3, 5, 6, 9]; (2) no fluid flow was allowed between contact surfaces of the soft tissues [4, 8] which is inconsistent with the equation of mass conservation across the contact interface [10]; (3) zero fluid pressure boundary conditions were inaccurately applied around the contact area [7].

The Study of Permeability Revolution in Coal Reservoir during Methane Production

2011 ◽  
Vol 148-149 ◽  
pp. 1491-1499
Author(s):  
Bo Cui ◽  
Hao Liang Han ◽  
Derek Elsworth
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Pore Pressure ◽  
Methane Production ◽  
Gas Flow ◽  
Fluid Transport ◽  
Volumetric Strain ◽  
Element Model ◽  
Key Factor ◽  
Coal Reservoir

Permeability of coal is recognized as the most important parameter for fluid transport through the seams. A new finite element model is applied to quantify the gas flow, the deformation of matrix and the net change of permeability. After plenty of study of the permeability, the revolution of the permeability based on the pore pressure and the sorption-induced strain is built. The sorption which affects the volumetric strain is taken into consideration and the pore pressure is also been studied as a key factor for permeability and other relative parameters.

Damping Control in a Sandwich Structure With SMP Core

2015 ◽  
Author(s):  
Pauline Butaud ◽  
Morvan Ouisse ◽  
Emmanuel Foltête
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Sandwich Structure ◽  
Damping Ratio ◽  
Shape Memory Polymer ◽  
Viscoelastic Model ◽  
Element Model ◽  
Numerical Approach ◽  
Wide Frequency Range ◽  
Frequency Range

A shape memory polymer (SMP), the tBA/PEGDMA, is elaborated and characterized. The dynamic mechanical characterization of this SMP highlights promising damping properties. The frequency and temperature dependency of the SMP is represented by a viscoelastic model allowing the introduction of the material in the design process of complex structures. A composite sandwich is developed by coupling the SMP with aluminum skins. A finite element model is developed for modeling the behavior of the SMP when integrated in a sandwich structure. The damping performances obtained by the numerical approach are validated experimentally using modal analysis. The experimental results are found to be in good agreement with the predictions of the finite element model. Furthermore, it is found that the controlled heating of the SMP core allows damping the structure over a wide frequency range. The SMP core temperature is tuned from the time-temperature superposition through a calibration curve to correspond to optimal values of damping ratio in the frequency range of interest; a vibration attenuation of about 20dB is observed.

Analysis on Oil Extraction Progressing Cavity Pump Three-Dimensional Finite Element Model

2014 ◽  
Vol 644-650 ◽  
pp. 670-673
Author(s):  
Guo You Han ◽  
Ming Qi Wang ◽  
Yu Hou ◽  
Qiang Li
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Finite Element Model ◽  
Fluid Pressure ◽  
Three Dimensional ◽  
Element Model ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Analysis Model ◽  
Element Analysis

The finite element analysis of PCP involves three nonlinear of geometry, material and contact, and the load of PCP is diversity, leading to it difficult to establish the finite element model and calculate by finite method. This article takes GLB120-27 as an example, to establish 3D solid model of PCP by using SolidWorks; to determine M-R model constant of stator rubber by using the data of uniaxial tensile test: to separate the seal band from the stator chamber by using Boolean operation and set up contact pairs, to achieve the correct simulation of stator chamber fluid pressure; to correctly simulate the interference fit between stator and rotor through setting correlation parameters; to establish 3D finite element analysis model and verify the correctness by using the experiment data of hydraulic characteristics of PCP.

Design Curves for Maximum Stresses in Blocks Containing Pressurized Bore Intersections

1991 ◽  
Vol 113 (4) ◽  
pp. 427-431 ◽  
Author(s):  
J. R. Sorem ◽  
J. R. Shadley ◽  
S. M. Tipton
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Approximation Method ◽  
Fluid Pressure ◽  
Element Model ◽  
Industrial Applications ◽  
Sound Design ◽  
The Finite Element Model ◽  
Maximum Stresses ◽  
Block Dimensions

Intersecting bore geometries are used in a number of industrial applications such as in fluid ends of reciprocating pumps. Maximum tensile stresses at stress concentration points in the block can be many times the fluid pressure in the bores. Obtaining good estimates of the maximum stresses in the structure is necessary for making sound design decisions on the block dimensions. Finite element models of the bore intersection geometry were analyzed for ranges of bore sizes and block dimensions. Results of the finite element model were compared with predictions provided by a popular approximation method based on mechanics of materials principles. The approximation method was found to underpredict the maximum stresses in the block in almost every case analyzed. For some conditions, the maximum stresses computed from the finite element model were more than two times the predictions provided by the approximation method. Design curves, based on the ratio of the sizes of the intersecting bores, are presented for selecting block dimensions to meet desired maximum stress criteria.

Cartilage Stresses in the Human Hip Joint

1994 ◽  
Vol 116 (1) ◽  
pp. 10-18 ◽  
Author(s):  
Thomas Macirowski ◽  
Slobodan Tepic ◽  
Robert W. Mann
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Fluid Pressure ◽  
Element Model ◽  
Contact Network ◽  
Physiological Level ◽  
Long Duration ◽  
Joint Lubrication ◽  
Constitutive Properties

The total surface stress measured in vitro on acetabular cartilage when step-loaded by an instrumented hemiprosthesis are partitioned into fluid and cartilage network stresses using a finite element model of the cartilage layer and measurements of the layer consolidation. The finite element model is based on in situ measurements of cartilage geometry and constitutive properties. Unique instrumentation was employed to collect the geometry and constitutive properties and pressure and consolidation data. When loaded, cartilage consolidates and exudes its interstitial fluid through and from its solid network into the interarticular gap. The finite element solutions include the spatial distributions of fluid and network stresses, the normal flow velocities into the gap, and the contact network stresses at the cartilage surface, all versus time. Even after long-duration application of physiological-level force, fluid pressure supports 90 percent of the load with the cartilage network stresses remaining well below the drained modulus of cartilage. The results support the “weeping” mechanism of joint lubrication proposed by McCutchen.

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