scholarly journals Finite element analysis of middle cervical spine

2021 ◽  
Author(s):  
Noushin Bahramshahi
Keyword(s):  
Spinal Cord ◽  
Finite Element ◽  
Cervical Spine ◽  
Three Dimensional ◽  
Spinal Column ◽  
Element Model ◽  
Published Data ◽  
Element Analysis ◽  
Flexion Extension ◽  
Disc Bulge

The spinal cord may be injured through various spinal column injury patterns. However, the relationship between column injury pattern and cord damage is not well understood. This investigation was conducted to develop a detailed, asymmetric three-dimensional finite element model of the C3-C5 cervical spine. The model was validated by comparing the simulation results obtained in this study with experimental published data. Upon validation of the model, the spinal cord was included into the model the simulation were performed. The disc bulge in the model with spinal cord were measured and compared with the results of the model without spinal cord. The results showed that inclusion of the spinal cord reduced the amount of lateral disc bulged. The results of the analysis of the model with spinal cord showed that in compression, the anterior surface of spinal cord sees more displacement, stress and strain that posterior surface and vice versa for flexion/extension.

scholarly journals Finite element analysis of middle cervical spine

2021 ◽  
Author(s):  
Noushin Bahramshahi
Keyword(s):  
Spinal Cord ◽  
Finite Element ◽  
Cervical Spine ◽  
Three Dimensional ◽  
Spinal Column ◽  
Element Model ◽  
Published Data ◽  
Element Analysis ◽  
Flexion Extension ◽  
Disc Bulge

The spinal cord may be injured through various spinal column injury patterns. However, the relationship between column injury pattern and cord damage is not well understood. This investigation was conducted to develop a detailed, asymmetric three-dimensional finite element model of the C3-C5 cervical spine. The model was validated by comparing the simulation results obtained in this study with experimental published data. Upon validation of the model, the spinal cord was included into the model the simulation were performed. The disc bulge in the model with spinal cord were measured and compared with the results of the model without spinal cord. The results showed that inclusion of the spinal cord reduced the amount of lateral disc bulged. The results of the analysis of the model with spinal cord showed that in compression, the anterior surface of spinal cord sees more displacement, stress and strain that posterior surface and vice versa for flexion/extension.

Development and Validation of a Three-Dimensional Finite Element Model of Cervical Spine (C3-C5)

2010 ◽  
Author(s):  
N. Bahramshahi ◽  
H. Ghaemi ◽  
K. Behdinan
Keyword(s):  
Finite Element ◽  
Cervical Spine ◽  
Three Dimensional ◽  
Element Model ◽  
Intervertebral Discs ◽  
Fe Model ◽  
Two Phase ◽  
Finite Element Software ◽  
Flexion Extension ◽  
Disc Bulge

The objective of this investigation is to develop a detailed, non-linear asymmetric three-dimensional anatomically and mechanically accurate FE model of complete middle cervical spine (C3-C5) using Hypermesh and MSC.Marc software. To achieve this goal, the components of the cervical spine are modeled using 20-noded hexagonal elements. The model includes the intervertebral disc, cortical bone, cancellous bone, endplates, and ligaments. The structure and dimensions of each spinal component are compared with experimentally measured values. In addition, the soil mechanics formulation of MSC.Marc finite element software is applied to model the mechanical behaviour of vertebrae and intervertebral discs as linear isotropic two-phase (biphasic) material. The FE simulation is conducted to investigate compression, flexion\extension and right\Left lateral bending modes. The simulation results are validated and compared closely with the published experimental data and the existing FE models. In general, results show greater flexibility in flexion and less flexibility in extension. The flexion/extension curves are asymmetric with a greater magnitude in flexion than in extension. In addition, the variations of the predicted lateral C4-C5 disc bulge are investigated and the results show that the maximum disc bulge occurs at the C4-C5 anterior location.

FEBio finite element model of a pediatric cervical spine

2021 ◽  
pp. 1-7
Author(s):  
Sean M. Finley ◽  
J. Harley Astin ◽  
Evan Joyce ◽  
Andrew T. Dailey ◽  
Douglas L. Brockmeyer ◽  
...  
Keyword(s):  
Finite Element ◽  
Cervical Spine ◽  
Finite Element Model ◽  
Material Properties ◽  
Surgical Simulation ◽  
Element Model ◽  
Axial Stiffness ◽  
Published Data ◽  
Axial Tension ◽  
Flexion Extension

OBJECTIVE The underlying biomechanical differences between the pediatric and adult cervical spine are incompletely understood. Computational spine modeling can address that knowledge gap. Using a computational method known as finite element modeling, the authors describe the creation and evaluation of a complete pediatric cervical spine model. METHODS Using a thin-slice CT scan of the cervical spine from a 5-year-old boy, a 3D model was created for finite element analysis. The material properties and boundary and loading conditions were created and model analysis performed using open-source software. Because the precise material properties of the pediatric cervical spine are not known, a published parametric approach of scaling adult properties by 50%, 25%, and 10% was used. Each scaled finite element model (FEM) underwent two types of simulations for pediatric cadaver testing (axial tension and cardinal ranges of motion [ROMs]) to assess axial stiffness, ROM, and facet joint force (FJF). The authors evaluated the axial stiffness and flexion-extension ROM predicted by the model using previously published experimental measurements obtained from pediatric cadaveric tissues. RESULTS In the axial tension simulation, the model with 50% adult ligamentous and annulus material properties predicted an axial stiffness of 49 N/mm, which corresponded with previously published data from similarly aged cadavers (46.1 ± 9.6 N/mm). In the flexion-extension simulation, the same 50% model predicted an ROM that was within the range of the similarly aged cohort of cadavers. The subaxial FJFs predicted by the model in extension, lateral bending, and axial rotation were in the range of 1–4 N and, as expected, tended to increase as the ligament and disc material properties decreased. CONCLUSIONS A pediatric cervical spine FEM was created that accurately predicts axial tension and flexion-extension ROM when ligamentous and annulus material properties are reduced to 50% of published adult properties. This model shows promise for use in surgical simulation procedures and as a normal comparison for disease-specific FEMs.

CT Based Three Dimensional Geometric Model of Cervical Spine

2013 ◽  
Vol 273 ◽  
pp. 588-592
Author(s):  
Zhi Yuan Yan ◽  
Dong Mei Wu ◽  
Li Tao Zhang ◽  
Jun Zhao
Keyword(s):  
Finite Element ◽  
Cervical Spine ◽  
Geometric Model ◽  
Three Dimensional ◽  
Element Model ◽  
Skeletal System ◽  
High Quality ◽  
Element Analysis ◽  
Dimensional Reconstruction ◽  
The Finite Element Model

In order to obtain high-quality analytical results of the finite element model, it is essential to construct a three dimensional geometric model. The paper reconstructed an accurate three dimensional geometric model of cervical spine segments (C4-C7). The process of reconstruction included three-dimensional reconstruction, smooth processing, contour generation, grid generation and fitting surface. Moreover, the result of reconstruction was evaluated ultimately. The model was validated to be smooth and reasonable, and could meet the requirements of finite element analysis. The method is not merely applied to reconstruct the geometric model of the cervical spine. It is a way to construct the model of the skeletal system of the human body.

A Three-Dimensional Dynamic Finite Element Model of the Prosthetic Knee Joint: Simulation of Joint Laxity and Kinematics

2005 ◽  
Vol 219 (6) ◽  
pp. 415-424 ◽  
Author(s):  
M Barink ◽  
A van Kampen ◽  
M de Waal Malefijt ◽  
N Verdonschot
Keyword(s):  
Finite Element ◽  
Knee Joint ◽  
Finite Element Model ◽  
Mathematical Formulation ◽  
Three Dimensional ◽  
Element Model ◽  
Joint Kinematics ◽  
Published Data ◽  
Dynamic Finite Element ◽  
Flexion Extension

For testing purposes of prostheses at a preclinical stage, it is very valuable to have a generic modelling tool, which can be used to optimize implant features and to avoid poor designs being launched on to the market. The modelling tool should be fast, efficient, and multipurpose in nature; a finite element model is well suited to the purpose. The question posed in this study was whether it was possible to develop a mathematically fast and stable dynamic finite element model of a knee joint after total knee arthroplasty that would predict data comparable with published data in terms of (a) laxities and ligament behaviour, and (b) joint kinematics. The soft tissue structures were modelled using a relatively simple, but very stable, composite model consisting of a band reinforced with fibres. Ligament recruitment and balancing was tested with laxity simulations. The tibial and patellar kinematics were simulated during flexion-extension. An implicit mathematical formulation was used. Joint kinematics, joint laxities, and ligament recruitment patterns were predicted realistically. The kinematics were very reproducible and stable during consecutive flexion-extension cycles. Hence, the model is suitable for the evaluation of prosthesis design, prosthesis alignment, ligament behaviour, and surgical parameters with respect to the biomechanical behaviour of the knee.

Torsional Analysis of a Steel Cord-Rubber Tire Belt Structure

1996 ◽  
Vol 24 (4) ◽  
pp. 339-348 ◽  
Author(s):  
R. M. V. Pidaparti
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Composite Structures ◽  
Three Dimensional ◽  
Element Model ◽  
Torsional Stiffness ◽  
Element Analysis ◽  
Rubber Belt ◽  
Steel Cord ◽  
Torsional Analysis

Abstract A three-dimensional (3D) beam finite element model was developed to investigate the torsional stiffness of a twisted steel-reinforced cord-rubber belt structure. The present 3D beam element takes into account the coupled extension, bending, and twisting deformations characteristic of the complex behavior of cord-rubber composite structures. The extension-twisting coupling due to the twisted nature of the cords was also considered in the finite element model. The results of torsional stiffness obtained from the finite element analysis for twisted cords and the two-ply steel cord-rubber belt structure are compared to the experimental data and other alternate solutions available in the literature. The effects of cord orientation, anisotropy, and rubber core surrounding the twisted cords on the torsional stiffness properties are presented and discussed.

Finite Element Analysis of Nonuniformity of Tires with Imperfections5

2007 ◽  
Vol 35 (3) ◽  
pp. 226-238 ◽  
Author(s):  
K. M. Jeong ◽  
K. W. Kim ◽  
H. G. Beom ◽  
J. U. Park
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Element Model ◽  
Radial Force ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Dimensional Finite Element ◽  
Force Variation ◽  
Three Dimensional Finite Element

Abstract The effects of variations in stiffness and geometry on the nonuniformity of tires are investigated by using the finite element analysis. In order to evaluate tire uniformity, a three-dimensional finite element model of the tire with imperfections is developed. This paper considers how imperfections, such as variations in stiffness or geometry and run-out, contribute to detrimental effects on tire nonuniformity. It is found that the radial force variation of a tire with imperfections depends strongly on the geometrical variations of the tire.

scholarly journals Comparison of Tooth- and Bone-Borne Appliances on the Stress Distributions and Displacement Patterns in the Facial Skeleton in Surgically Assisted Rapid Maxillary Expansion—A Finite Element Analysis (FEA) Study

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1152
Author(s):  
Rafał Nowak ◽  
Anna Olejnik ◽  
Hanna Gerber ◽  
Roman Frątczak ◽  
Ewa Zawiślak
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Element Model ◽  
Rapid Maxillary Expansion ◽  
Stress Distributions ◽  
Maxillary Expansion ◽  
Facial Skeleton ◽  
Element Analysis ◽  
Maxillary Constriction

The aim of this study was to compare the reduced stresses according to Huber’s hypothesis and the displacement pattern in the region of the facial skeleton using a tooth- or bone-borne appliance in surgically assisted rapid maxillary expansion (SARME). In the current literature, the lack of updated reports about biomechanical effects in bone-borne appliances used in SARME is noticeable. Finite element analysis (FEA) was used for this study. Six facial skeleton models were created, five with various variants of osteotomy and one without osteotomy. Two different appliances for maxillary expansion were used for each model. The three-dimensional (3D) model of the facial skeleton was created on the basis of spiral computed tomography (CT) scans of a 32-year-old patient with maxillary constriction. The finite element model was built using ANSYS 15.0 software, in which the computations were carried out. Stress distributions and displacement values along the 3D axes were found for each osteotomy variant with the expansion of the tooth- and the bone-borne devices at a level of 0.5 mm. The investigation showed that in the case of a full osteotomy of the maxilla, as described by Bell and Epker in 1976, the method of fixing the appliance for maxillary expansion had no impact on the distribution of the reduced stresses according to Huber’s hypothesis in the facial skeleton. In the case of the bone-borne appliance, the load on the teeth, which may lead to periodontal and orthodontic complications, was eliminated. In the case of a full osteotomy of the maxilla, displacements in the buccolingual direction for all the variables of the bone-borne appliance were slightly bigger than for the tooth-borne appliance.

A New Computer Simulation of Neck Injury Biomechanics

2011 ◽  
Vol 467-469 ◽  
pp. 339-344
Author(s):  
Na Li ◽  
Jian Xin Liu
Keyword(s):  
Finite Element ◽  
Cervical Spine ◽  
Head And Neck ◽  
Traffic Accidents ◽  
Ethical Issues ◽  
Human Head ◽  
Element Model ◽  
Neck Injury ◽  
Element Analysis ◽  
Injury Mechanisms

Head and neck injuries are the most frequent severe injury resulting from traffic accidents. Neck injury mechanisms are difficult to study experimentally due to the variety of impact conditions involved, as well as ethical issues, such as the use of human cadavers and animals. Finite element analysis is a comprehensive computer aided mathematical method through which human head and neck impact tolerance can be investigated. Detailed cervical spine models are necessary to better understand cervical spine response to loading, improve our understanding of injury mechanisms, and specifically for predicting occupant response and injury in auto crash scenarios. The focus of this study was to develop a C1–C2 finite element model with optimized mechanical parameter. The most advanced material data available were then incorporated using appropriate nonlinear constitutive models to provide accurate predictions of response at physiological levels of loading. This optimization method was the first utilized in biomechanics understanding, the C1–C2 model forms the basis for the development of a full cervical spine model. Future studies will focus on tissue-level injury prediction and dynamic response.

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