Biomechanical Alterations in Intact Osteoporotic Spine Due to Synthetic Augmentation: Finite Element Investigation

2006 ◽  
Vol 129 (4) ◽  
pp. 575-585 ◽  
Author(s):  
Kathryn B. Higgins ◽  
David R. Sindall ◽  
Alberto M. Cuitino ◽  
Noshir A. Langrana
Keyword(s):  
Finite Element ◽  
Bone Cement ◽  
Vertebral Body ◽  
Failure Load ◽  
Three Dimensional ◽  
Element Model ◽  
Nonlinear Finite Element ◽  
Poor Bone Quality ◽  
Therapeutic Benefits ◽  
Nonlinear Finite Element Model

A three-dimensional nonlinear finite element model (FEM) was developed for a parametric study that examined the effect of synthetic augmentation on nonfractured vertebrae. The objective was to isolate those parameters primarily responsible for the effectiveness of the procedure; bone cement volume and bone density were expected to be highly important. Injection of bone cement was simulated in the FEM of a vertebral body that included a cellular model for the trabecular core. The addition of 10% and 20% cement by volume resulted in an increase in failure load, and the larger volume resulted in an increase in stiffness for the vertebral body. Placement of cement within the vertebral body was not as critical a parameter as cement amount. Simulated models of very poor bone quality saw the best therapeutic benefits.

A Three-Dimenstional Nonlinear Finite Element Model of Lumbar Intervertebral Joint in Torsion

1987 ◽  
Vol 109 (3) ◽  
pp. 200-209 ◽  
Author(s):  
K. Ueno ◽  
Y. K. Liu
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Three Dimensional ◽  
Element Model ◽  
Nonlinear Finite Element ◽  
Stress Distributions ◽  
Cause Of Failure ◽  
Disk Prolapse ◽  
Nonlinear Finite Element Model

Torsion as a cause of failure in the lumbar intervertebral joint was studied using a three-dimensional nonlinear finite element model. The role of facets and ligaments as well as the stress distributions in the posterior elements, the disk, the ligaments, and the vertebral body were examined. For physiological range of torsion, the facets carried 10 to 40 percent of the torque. The fiber stresses in the disk were the highest at the lateral margin of the outer layer of the annulus. Therefore, torsion itself is unlikely to cause posterior or posterolateral disk prolapse.

A New Tightening Methodology for Gasketed Joints Based on Nonlinear Finite Element Analysis

2008 ◽  
Author(s):  
Sayed A. Nassar ◽  
Zhijun Wu ◽  
Xianjie Yang
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Elastic Interaction ◽  
Element Model ◽  
Nonlinear Finite Element ◽  
Bolted Joints ◽  
Model Parameters ◽  
Element Analysis ◽  
Loading And Unloading ◽  
Nonlinear Finite Element Model

A three dimensional nonlinear finite element model is developed for achieving a uniform clamp load in gasketed bolted joints. The model is used for both multiple and single pass tightening patterns. Geometric nonlinearity of the gasket is taken into account and plastic model parameters are experimentally determined. The effect of the tightening pattern, gasket loading and unloading history, and the preload level is investigated. The validity of the FEA methodology is experimentally verified. This study helps improve the reliability of gasketed bolted joints by minimizing the bolt-to-bolt clamp load variation caused by elastic interaction among the various bolts in the joint during initial joint bolt-up.

Three-Dimensional Nonlinear Finite Element Model for Simulating Pavement Response: Study at Canterbury Accelerated Pavement Testing Indoor Facility, New Zealand

2003 ◽  
Vol 1823 (1) ◽  
pp. 153-162 ◽  
Author(s):  
Mofreh F. Saleh ◽  
Bruce Steven ◽  
David Alabaster
Keyword(s):  
Finite Element ◽  
New Zealand ◽  
Finite Element Model ◽  
Three Dimensional ◽  
Element Model ◽  
Nonlinear Finite Element ◽  
3D Fem ◽  
Accelerated Pavement Testing ◽  
Pavement Testing ◽  
Nonlinear Finite Element Model

A three-dimensional nonlinear finite element model (3D-FEM) was developed as part of a study of the effect of increasing axle load and tire pressure on pavement deterioration. The measured strains, interface stresses, and deflections were collected from the instrumented Canterbury Accelerated Pavement Testing Indoor Facility in New Zealand. In addition, two multilayer elastic models were used to compare the values from the finite element simulation and the actual measurements. The first elastic multilayer model was developed with ELSYM5 software, and the second model was developed with CIRCLY software. CIRCLY differs from ELSYM5 in the ability to account for material anisotropy; ELSYM5 considers the pavement materials to be isotropic. The actual strains and deformations were measured by Emu strain gauges embedded at different depths in the base and subgrade materials. Both the unbound granular base and the subgrade materials were modeled in 3D-FEM as elastic plastic materials. The results showed that for the unbound base layer, the strains calculated from the two elastic models were in reasonable agreement with the values measured in the instrumented test track, while the 3D-FEM model tended to overestimate the strains at the bottom of the base. While none of the models provided a perfect fit to the measured strains in the subgrade layer because the subgrade is less homogenous than assumed, 3D-FEM provided the closest fit. Also, CIRCLY provided better results than ELSYM5, which underestimated the displacement values compared with values obtained with CIRCLY and 3D-FEM.

Multi-Physics Coupling Field Nonlinear Finite Element Model for Giant Magnetostrictive Smart Component

2014 ◽  
Vol 543-547 ◽  
pp. 617-620
Author(s):  
Xiao Mei Sui ◽  
Zhang Rong Zhao ◽  
Wen Zuo Chen ◽  
Xiao Yu Zhang
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Element Model ◽  
Nonlinear Finite Element ◽  
Finite Element Software ◽  
Magnetostrictive Strain ◽  
Resonance Frequencies ◽  
Giant Magnetostrictive Materials ◽  
Nonlinear Finite Element Model ◽  
Good Agreement

This paper presents three dimensional nonlinear finite element modeling of giant magnetostrictive materials. The nonlinear relationship between magnetostrictive strain and magnetic field is described by experimental curve. Model is implemented using finite element software CMOSOL multiphysics 3.2a. A new method for precise machining non-cylinder pin hole of piston by using embedded giant magnetostrictive smart component is presented. The effects on smart component deformation and the system resonance frequencies are studied. This model is verified against experimental results, with a good agreement.

Achieving Uniform Clamp Load in Gasketed Bolted Joints Using a Nonlinear Finite Element Model

2010 ◽  
Vol 132 (3) ◽  
Author(s):  
Sayed A. Nassar ◽  
Zhijun Wu ◽  
Xianjie Yang
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Three Dimensional ◽  
Elastic Interaction ◽  
Element Model ◽  
Nonlinear Finite Element ◽  
Bolted Joints ◽  
Model Parameters ◽  
Loading And Unloading ◽  
Nonlinear Finite Element Model

A three-dimensional nonlinear finite element model is developed for achieving a uniform clamp load in gasketed bolted joints. The model is used for both multiple and single pass tightening patterns. Geometric nonlinearity of the gasket is taken into account and plastic model parameters are experimentally determined. The effect of the tightening pattern, gasket loading and unloading history, and the preload level is investigated. The validity of the FEA methodology is experimentally verified. This study helps improve the reliability of gasketed bolted joints by minimizing the bolt-to-bolt clamp load variation caused by elastic interaction among the various bolts in the joint during initial joint-bolt-up.

On the Three-Dimensional Computation of Steel-Belted Tires

1986 ◽  
Vol 14 (2) ◽  
pp. 116-124 ◽  
Author(s):  
H. Rothert ◽  
R. Gall
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Three Dimensional ◽  
Element Model ◽  
Nonlinear Finite Element ◽  
Geometrically Nonlinear ◽  
Linear Elastic ◽  
Shear Strains ◽  
Nonlinear Finite Element Model ◽  
The Finite Element Model

Abstract A geometrically-nonlinear finite element model of a complete tire is used in an analysis for inflation and footprint loadings. Each reinforced layer of the tire is approximated as being homogeneous, orthotropic, and linear elastic. The finite element model used in the analysis allows the computation of interply shear strains due to inflation and footprint loads. Some numerical results on loaded tires are also presented and compared with those obtained experimentally.

A Dynamic, Nonlinear Finite-Element Model of a Human Leg

1979 ◽  
Vol 101 (3) ◽  
pp. 176-184 ◽  
Author(s):  
T. K. Hight ◽  
R. L. Piziali ◽  
D. A. Nagel
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Three Dimensional ◽  
Complex Loading ◽  
Element Model ◽  
Nonlinear Finite Element ◽  
Cross Sectional ◽  
Downhill Skiing ◽  
Stiffness Characteristics ◽  
Nonlinear Finite Element Model

The development of a dynamic, nonlinear finite-element model of a human leg is presented. The model is designed to accommodate large three-dimensional displacements and rotations, to accurately reflect the nonlinear stiffness characteristics of the knee joint, and to facilitate efficient stress-level calculations. Numerical examples are presented which demonstrate the nonlinear capabilities of the model. In addition, a brief example illustrates the ability of the model to respond to a complex loading history measured during a downhill skiing maneuver and to predict cross-sectional stress levels.

Sign in / Sign up

Export Citation Format

Share Document