scholarly journals A musculoskeletal finite element model of rat knee joint for evaluating cartilage biomechanics during gait

2021 ◽  
Author(s):  
Gustavo A. Orozco ◽  
Kalle Karjalainen ◽  
Eng Kuan Moo ◽  
Lauri Stenroth ◽  
Petri Tanska ◽  
...  
Keyword(s):  
Finite Element ◽  
Animal Models ◽  
Knee Joint ◽  
Gait Cycle ◽  
Numerical Models ◽  
Small Animal ◽  
Element Model ◽  
Lateral Compartment ◽  
Fe Model ◽  
Joint Injury

Abnormal loading of the knee due to injuries or obesity is thought to contribute to the development of osteoarthritis (OA). Small animal models have been used for studying OA progression mechanisms. However, numerical models to study cartilage responses under dynamic loading in preclinical animal models have not been developed. Here we present a musculoskeletal finite element (FE) model of a rat knee joint to evaluate cartilage biomechanical responses during a gait cycle. The rat knee joint geometries were obtained from a 3-D MRI dataset and the boundary conditions regarding loading in the joint were extracted from a musculoskeletal model of the rat hindlimb. The fibril-reinforced poroelastic (FRPE) properties of the rat cartilage were derived from data of mechanical indentation tests. Our numerical results showed the relevance of simulating anatomical and locomotion characteristics in the rat knee joint for estimating tissue responses such as contact pressures, stresses, strains, and fluid pressures. We found that the contact pressure and maximum principal strain were virtually constant in the medial compartment whereas they showed the highest values at the beginning of the gait cycle in the lateral compartment. Furthermore, we found that the maximum principal stress increased during the stance phase of gait, with the greatest values at midstance. We anticipate that our approach serves as a first step towards investigating the effects of gait abnormalities on the adaptation and degeneration of rat knee joint tissues and could be used to evaluate biomechanically-driven mechanisms of the progression of OA as a consequence of joint injury or obesity.

Numerical and Experimental Analysis of Articular Chondrocyte Deformation: Calibration of a Multiscale Finite Element Model

2007 ◽  
Author(s):  
Scott L. Bevill ◽  
Paul L. Briant ◽  
Thomas P. Andriacchi
Keyword(s):  
Finite Element ◽  
Load Transfer ◽  
Numerical Models ◽  
Experimental Studies ◽  
Element Model ◽  
Cartilage Explants ◽  
Fe Model ◽  
Articular Chondrocyte ◽  
Superficial Zone

Mechanical loading of chondrocytes in isolation [1] and of articular cartilage in culture [2] has been reported to be a potent regulator of chondrocyte metabolism. Experimental studies have related tissue-level and cell-level strains in mechanically loaded cartilage explants [3], but cannot be readily extended to address more physiologic loading cases. Numerical models, which might address this need, have primarily been axisymmetric [4, 5] or two-dimensional [6] and have idealized chondrocyte geometry. Given the complexity of the mechanism of the load transfer between the tissue and cell, however, there remains a lack of information regarding the in vivo level of cell stresses and strains. Thus, the purpose of this study was to develop a multiscale experimental/numerical approach to calibrate a three-dimensional finite element (FE) model of a chondrocyte based on experimentally derived chondrocyte morphology and deformation data. The method was than applied to determine the modulus of a chondrocyte located in the superficial zone.

Development of a 3-D Non-Linear Finite Element Model of Human Knee Joint

2002 ◽  
Author(s):  
Yuhua Song ◽  
Richard E. Debski ◽  
Jorge Gil ◽  
Savio L.-Y. Woo
Keyword(s):  
Finite Element ◽  
Knee Joint ◽  
Soft Tissues ◽  
Cruciate Ligament ◽  
Element Model ◽  
Fe Model ◽  
Full Extension ◽  
Human Knee ◽  
Human Knee Joint ◽  
Non Linear

A 3-D finite element (FE) model of the knee is needed to more accurately analyze the kinematics of a knee joint as well as the function of various soft tissues such as ligaments. The data obtained can provide a better understanding of mechanisms of injury and offer valuable information for ligament reconstruction and rehabilitation protocols. The objective of this study was to develop a 3-D non-linear FE model of a human knee and determine its kinematics and the force and stress distributions within the anterior cruciate ligament (ACL) in response to anterior tibial loads at full extension. This model was validated by comparing the computed results to data obtained experimentally by a Robotic/UFS testing system [1].

Fatigue Assessment of a Slender Footbridge Based on an Updated Finite Element Model

2018 ◽  
Vol 774 ◽  
pp. 589-594
Author(s):  
J. Pérez-Aracil ◽  
A.M. Hernandez-Díaz ◽  
J.F. Jiménez-Alonso ◽  
F.J. Puerta-Lopez
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Fatigue Damage ◽  
Model Updating ◽  
Numerical Models ◽  
Vertical Direction ◽  
Element Model ◽  
Modal Parameters ◽  
Fe Model ◽  
Fatigue Assessment

Finite element model updating is a well-known technique to better characterize the real behaviour of civil engineering structures. The updated numerical model can be used to perform a more accurate structural assessment. Herein, its effectiveness is validated through the fatigue assessment of a lively footbridge considering two different numerical models: (i) a preliminary finite element (FE) model and (ii) an updated version of the preliminary model based on the modal parameters of the footbridge identified experimentally. For this purpose, the Malecon footbridge (Murcia, Spain) has been considered. This footbridge, a cable-stayed structure, is prone to vibrate in vertical direction under continuous walking pedestrian flows so fatigue damage might be expected on its supporting cables. A detailed FE model of the footbridge has been performed and subsequently updated based on the experimental modal parameters of the structure. The behaviour of the pedestrian flows was characterized by field observations. Finally, a comparison is performed between the fatigue damage of some cables of the footbridge considering the two mentioned FE models. The safe life method was used to assess such damage. As result, a maximum relative difference around 52 % was obtained between the two numerical models.

The Impact of an Open-Book Pelvic Ring Injury on Bone Strain: Validation of a Finite Element Model and Analysis Within the Gait Cycle

2021 ◽  
Vol 143 (7) ◽  
Author(s):  
Zoryana Salo ◽  
Hans Kreder ◽  
Cari Marisa Whyne
Keyword(s):  
Finite Element ◽  
Gait Cycle ◽  
Pelvic Ring ◽  
Element Model ◽  
Heel Strike ◽  
Fe Model ◽  
Open Book ◽  
Pubic Ramus ◽  
Biomechanical Behavior ◽  
The Impact

Abstract The threshold for surgical stabilization for an open-book pelvic fracture is not well defined. The purpose of this research was to validate the biomechanical behavior of a specimen-specific pelvic finite element (FE) model with an open-book fracture with the biomechanical behavior of a cadaveric pelvis in double leg stance configuration under physiologic loading, and to utilize the validated model to compare open book versus intact strain patterns during gait. A cadaveric pelvis was experimentally tested under compressive loading in double leg stance, intact, and with a simulated open-book fracture. An intact FE model of this specimen was reanalyzed with an equivalent simulated open-book fracture. Comparison of the FE generated and experimentally measured strains yielded an R2 value of 0.92 for the open-book fracture configuration. Strain patterns in the intact and fractured models were compared throughout the gait cycle. In double leg stance and heel-strike/heel-off models, tensile strains decreased, especially in the pubic ramus contralateral to the injury, and compressive strains increased in the sacroiliac region of the injured side. In the midstance/midswing gait configuration, higher tensile and compressive FE strains were observed on the midstance side of the fractured versus intact model and decreased along the superior and inferior pubic rami and ischium, with midswing side strains reduced almost to zero in the fractured model. Identified in silico patterns align with clinical understanding of open-book fracture pathology suggesting future potential of FE models to quantify instability and optimize fixation strategies.

The Study of Stress Distribution on Meniscus Using 3D Finite Element Model

2015 ◽  
Vol 749 ◽  
pp. 427-432
Author(s):  
Pavinee Laopachee ◽  
Pattaraweerin Woraratsoontorn ◽  
Joompondej Bamrungwongtaree
Keyword(s):  
Finite Element ◽  
Body Weight ◽  
Stress Distribution ◽  
Knee Joint ◽  
External Load ◽  
Element Model ◽  
The Body ◽  
Three Dimensions ◽  
Von Mises Stress ◽  
Fe Model

Osteoarthritis is a degenerative disease of articular cartilageand meniscus that most experience in aged and obesity, always tend to grow up. Such bone surface degenerated will beirregular and has bone to grow called osteophyte. At moment making activities, the pain and the deformation of the knee joint are occurred thatcause decreasing quality of life. The deterioratedmeniscus has to encountersgradually changing the structureuntil it is not able to support the body weight. This paper proposes the preliminary studyof the knee jointbehavior, especially the meniscus during stand. Three dimensions (3-D) finite element (FE) model of the knee joint has constructed. This model consisted of femur, tibiaand meniscus without fibula.The external load were determined in each body weight and appliedon femur to evaluate maximum von-mises stress on the meniscus.The stress distribution on meniscus always occurs while exist the external load on the femur. The tendency of association between the external load and maximumstress was corresponding to that of the other author.

Nanoscale Indentation of Simulated Soft Tissues

2004 ◽  
Author(s):  
Shikha Gupta ◽  
Fernando Carrillo ◽  
Lisa Pruitt ◽  
Christian Puttlitz
Keyword(s):  
Animal Models ◽  
Material Properties ◽  
Soft Tissues ◽  
Tissue Sample ◽  
Small Animal ◽  
Element Model ◽  
Small Time ◽  
Fe Model ◽  
Testing Procedures ◽  
Small Animal Models

The use of small animal models, such as murine and rabbit models, are currently being explored to help elucidate the mechanobiological mechanisms of clinically relevant orthopaedic conditions such as fracture healing and osteoarthritis progression, with the goal of developing a comprehensive view of the biomechanical structure-function relationships at the tissue and cellular level. In addition to the heterogeneous nature of these tissues, the miniature size of the test specimens from these small animal models precludes the use of conventional bulk mechanical testing procedures to obtain material properties. Nanoindentation is a technique that is used to assess mechanical properties on a cellular scale. Though traditionally used to study hard, elastic-plastic materials, it has been effectively utilized to measure the material properties of mineralized biological materials [1, 2]. More recently, there have been some preliminary studies on soft, hydrated tissues, such as demineralized dentin, cartilage, and vascular tissues [3, 4]. However, this technique has not been validated for measuring the properties of tissues with extremely small, time- dependent tissue matrices (elastic moduli below 5 MPa). A finite element model (FE) of the nanoscale indentation process has been developed to assess some of the experimental issues associated with using nanoindentation on physical tissue specimens. In addition, we have used this FE model to predict the distribution of stresses and strains within the indenting substrate (tissue sample), mechanical parameters that cannot be mapped using currently-available experimental methods.

Finite Element Analysis of the Distributed Vibration Absorbers for Structural Noise Control

2005 ◽  
Author(s):  
Ashwini Gautam ◽  
Chris Fuller ◽  
James Carneal
Keyword(s):  
Finite Element ◽  
Numerical Model ◽  
Base Plate ◽  
Element Model ◽  
Fe Model ◽  
Vibration Absorbers ◽  
Element Analysis ◽  
Poroelastic Media ◽  
Hexahedral Elements ◽  
Component Models

This work presents an extensive analysis of the properties of distributed vibration absorbers (DVAs) and their effectiveness in controlling the sound radiation from the base structure. The DVA acts as a distributed mass absorber consisting of a thin metal sheet covering a layer of acoustic foam (porous media) that behaves like a distributed spring-mass-damper system. To assess the effectiveness of these DVAs in controlling the vibration of the base structures (plate) a detailed finite elements model has been developed for the DVA and base plate structure. The foam was modeled as a poroelastic media using 8 node hexahedral elements. The structural (plate) domain was modeled using 16 degree of freedom plate elements. Each of the finite element models have been validated by comparing the numerical results with the available analytical and experimental results. These component models were combined to model the DVA. Preliminary experiments conducted on the DVAs have shown an excellent agreement between the results obtained from the numerical model of the DVA and from the experiments. The component models and the DVA model were then combined into a larger FE model comprised of a base plate with the DVA treatment on its surface. The results from the simulation of this numerical model have shown that there has been a significant reduction in the vibration levels of the base plate due to DVA treatment on it. It has been shown from this work that the inclusion of the DVAs on the base plate reduces their vibration response and therefore the radiated noise. Moreover, the detailed development of the finite element model for the foam has provided us with the capability to analyze the physics behind the behavior of the distributed vibration absorbers (DVAs) and to develop more optimized designs for the same.

Finite Element Model of Human Cochlea Considering of the Helicotrema Size

2013 ◽  
Vol 456 ◽  
pp. 576-581 ◽  
Author(s):  
Li Fu Xu ◽  
Na Ta ◽  
Zhu Shi Rao ◽  
Jia Bin Tian
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Basilar Membrane ◽  
Round Window ◽  
Element Model ◽  
Oval Window ◽  
Fe Model ◽  
Cochlear Duct ◽  
Human Cochlea ◽  
Set Up

A 2-D finite element model of human cochlea is established in this paper. This model includes the structure of oval window, round window, basilar membrane and cochlear duct which is filled with fluid. The basilar membrane responses are calculated with sound input on the oval window membrane. In order to study the effects of helicotrema on basilar membrane response, three different helicotrema dimensions are set up in the FE model. A two-way fluid-structure interaction numerical method is used to compute the responses in the cochlea. The influence of the helicotrema is acquired and the frequency selectivity of the basilar membrane motion along the cochlear duct is predicted. These results agree with the experiments and indicate much better results are obtained with appropriate helicotrema size.

Finite Element Mesh Generator Applying Constraints’ Propagation and Isoparametric Mapping

1991 ◽  
Author(s):  
J. Rodriguez ◽  
M. Him
Keyword(s):  
Finite Element ◽  
Mesh Generation ◽  
Element Model ◽  
Finite Element Mesh ◽  
Fe Model ◽  
Element Analysis ◽  
Element Mesh ◽  
Mesh Generator ◽  
Generation Algorithm ◽  
Essential Input

Abstract This paper presents a finite element mesh generation algorithm (PREPAT) designed to automatically discretize two-dimensional domains. The mesh generation algorithm is a mapping scheme which creates a uniform isoparametric FE model based on a pre-partitioned domain of the component. The proposed algorithm provides a faster and more accurate tool in the pre-processing phase of a Finite Element Analysis (FEA). A primary goal of the developed mesh generator is to create a finite element model requiring only essential input from the analyst. As a result, the generator code utilizes only a sketch, based on geometric primitives, and information relating to loading/boundary conditions. These conditions represents the constraints that are propagated throughout the model and the available finite elements are uniformly mapped in the resulting sub-domains. Relative advantages and limitations of the mesh generator are discussed. Examples are presented to illustrate the accuracy, efficiency and applicability of PREPAT.

scholarly journals Low Cost Frictional Seismic Base-Isolation of Residential New Masonry Buildings in Developing Countries: A Small Masonry House Case Study

2017 ◽  
Vol 11 (1) ◽  
pp. 1026-1035 ◽  
Author(s):  
Ahmad Basshofi Habieb ◽  
Gabriele Milani ◽  
Tavio Tavio ◽  
Federico Milani
Keyword(s):  
Finite Element ◽  
Seismic Vulnerability ◽  
Base Isolation ◽  
Low Cost ◽  
Element Model ◽  
Shaking Table ◽  
Fe Model ◽  
Isolation System ◽  
Finite Element Software ◽  
Non Linear

Introduction:An advanced Finite Element model is presented to examine the performance of a low-cost friction based-isolation system in reducing the seismic vulnerability of low-class rural housings. This study, which is mainly numerical, adopts as benchmark an experimental investigation on a single story masonry system eventually isolated at the base and tested on a shaking table in India.Methods:Four friction isolation interfaces, namely, marble-marble, marble-high-density polyethylene, marble-rubber sheet, and marble-geosynthetic were involved. Those interfaces differ for the friction coefficient, which was experimentally obtained through the aforementioned research. The FE model adopted here is based on a macroscopic approach for masonry, which is assumed as an isotropic material exhibiting damage and softening. The Concrete damage plasticity (CDP) model, that is available in standard package of ABAQUS finite element software, is used to determine the non-linear behavior of the house under non-linear dynamic excitation.Results and Conclusion:The results of FE analyses show that the utilization of friction isolation systems could much decrease the acceleration response at roof level, with a very good agreement with the experimental data. It is also found that systems with marble-marble and marble-geosynthetic interfaces reduce the roof acceleration up to 50% comparing to the system without isolation. Another interesting result is that there was little damage appearing in systems with frictional isolation during numerical simulations. Meanwhile, a severe state of damage was clearly visible for the system without isolation.

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