scholarly journals Novel human intervertebral disc strain template to quantify regional three-dimensional strains in a population and compare to internal strains predicted by a finite element model

2016 ◽  
Vol 34 (7) ◽  
pp. 1264-1273 ◽  
Author(s):  
Brent L. Showalter ◽  
John F. DeLucca ◽  
John M. Peloquin ◽  
Daniel H. Cortes ◽  
Jonathon H. Yoder ◽  
...  
Keyword(s):  
Finite Element ◽  
Intervertebral Disc ◽  
Finite Element Model ◽  
Three Dimensional ◽  
Element Model ◽  
Internal Strains

scholarly journals Does the Screw Position in the ACDF Affect the Degeneration of Adjacent Segments? A Three-Dimensional Finite Element Analysis

2020 ◽  
Author(s):  
Kai Guo ◽  
Jiawei Lu ◽  
Ziqi Zhu ◽  
Beiduo Shen ◽  
Tongde Wu ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Intervertebral Disc ◽  
Finite Element Model ◽  
Three Dimensional ◽  
Element Model ◽  
Adjacent Segment ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

Abstract Background: ACDF is the main treatment of cervical disease. Adjacent Segment Degeneration (ASD) is the main complication of long-term follow-up of ACDF. we conduct a detailed study of ACDF by means of three-dimensional finite element analysis and find the effect of screw placement and location on the occurrence of ASD.Methods: The cervical computed tomography (CT) data (layer thickness of 0.625 mm) for a 30-year-old healthy male volunteer was collected. All the data were combined to create a C2-7 3D finite element model using Abaqus software. Based on the data and the actual surgical maneuver, a screw positioning model was established, in order to observe the cervical range of motion (ROM) with different positions of screw, as well as the pressure change of the adjacent segment intervertebral disc.Results: The proposed finite element model of cervical spine was effective, and ROM on all directions of C4-C6 segments changed after ACDF surgery. Under the same torque settings, compared with the control group, C2/3 segment rotational ROM increased; C2/3, C3/4 segments lateral flexion ROM also increased. Regarding the influence of screw positioning, it has limited influence on the ROM and The intervertebral disc pressure (IDP), and compared with different horizontal positions, different vertical positions imposed greater influence on the ROM and IDP. Conclusions: For ACDF surgery, positioning the screw at the anterior inferior part of the cervical vertebral body could provide more natural cervical ROM and the least IDP, while maintaining high biomechanical stability, and is more in line with human biomechanical requirements.

Multiphasic Mechano-Electrochemical Finite Element Model of Human Intervertebral Disc

2007 ◽  
Author(s):  
Hai Yao ◽  
Wei Yong Gu
Keyword(s):  
Finite Element ◽  
Intervertebral Disc ◽  
Finite Element Model ◽  
Mechanical Loading ◽  
Human Body ◽  
Physical Environment ◽  
Annulus Fibrosus ◽  
Three Dimensional ◽  
Element Model ◽  
Mechanical Loads

The intervertebral disc (IVD) is the largest cartilaginous structure in human body that contributes to flexibility and load support in the spine. To accomplish these functions, the disc has a unique architecture consisting of a centrally-located nucleus pulposus (NP) surrounded superiorly and inferiorly by cartilage endplates and peripherally by the annulus fibrosus (AF). Because the disc is avascular and experiences mechanical loads, the cells in IVD tissues live in a complex physical environment. Knowledge of mechanical, chemical and electrical signals within the tissue is important for understanding mechanobiology of IVD [1]. The objective of this study was to develop a three-dimensional (3D), inhomogeneous finite element model (FEM) for human IVD for analyzing the physical environment and solute transport within the tissue under different mechanical loading conditions. A case of IVD under axial compression was simulated and reported.

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.

Reduction of Free-Edge Stress Concentration

1985 ◽  
Vol 52 (4) ◽  
pp. 801-805 ◽  
Author(s):  
P. R. Heyliger ◽  
J. N. Reddy
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
Finite Element Model ◽  
Three Dimensional ◽  
Element Model ◽  
Free Edge ◽  
Shear Stresses ◽  
Normal Stresses ◽  
Interlaminar Shear ◽  
Three Dimensional Elasticity

A quasi-three dimensional elasticity formulation and associated finite element model for the stress analysis of symmetric laminates with free-edge cap reinforcement are described. Numerical results are presented to show the effect of the reinforcement on the reduction of free-edge stresses. It is observed that the interlaminar normal stresses are reduced considerably more than the interlaminar shear stresses due to the free-edge reinforcement.

scholarly journals Numerical investigation of plastic flow and residual stresses generated in hydroformed tubes

2021 ◽  
pp. 146442072198974
Author(s):  
A Ktari ◽  
A Abdelkefi ◽  
N Guermazi ◽  
P Malecot ◽  
N Boudeau
Keyword(s):  
Finite Element ◽  
Residual Stresses ◽  
Finite Element Model ◽  
Plastic Flow ◽  
Tube Hydroforming ◽  
Three Dimensional ◽  
Element Model ◽  
Tube Cross Section ◽  
Straight Wall ◽  
Hydroforming Process

During tube hydroforming process, the friction conditions between the tube and the die have a great importance on the material plastic flow and the distribution of residual stresses of the final component. Indeed, a three-dimensional finite element model of a tube hydroforming process in the case of square section die has been performed, using dynamic and static approaches, to study the effect of the friction conditions on both plastic flow and residual stresses induced by the process. First, a comparative study between numerical and experimental results has been carried out to validate the finite element model. After that, various coefficients of friction were considered to study their effect on the thinning phenomenon and the residual stresses distribution. Different points have been retained from this study. The thinning is located in the transition zone cited between the straight wall and the corner zones of hydroformed tube due to the die–tube contact conditions changes during the process. In addition, it is clear that both die–tube friction conditions and the tube bending effects, which occurs respectively in the tube straight wall and corner zones, are the principal causes of the obtained residual stresses distribution along the tube cross-section.

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