Effects of implant orientation and implant material on tibia bone strain, implant–bone micromotion, contact pressure, and wear depth due to total ankle replacement

2019 ◽  
Vol 233 (3) ◽  
pp. 318-331 ◽  
Author(s):  
Subrata Mondal ◽  
Rajesh Ghosh
Keyword(s):  
Finite Element ◽  
Contact Pressure ◽  
Bone Strain ◽  
Finite Element Models ◽  
Wear Depth ◽  
Material Combination ◽  
Tibia Bone ◽  
Implant Material ◽  
Ankle Replacement ◽  
Strain Shielding

The aim of this study is to investigate the effects of implant orientation and implant material on tibia bone strain, implant–bone micromotion, maximum contact pressure, and wear depth at the articulating surface due to total ankle replacement. Three-dimensional finite element models of intact and implanted ankle were developed from computed tomography scan data. Four implanted models were developed having varus and valgus orientations of 5° and 10°, respectively. In order to determine the effect of implant material combination on tibia bone strain, micromotion, contact pressure, and wear depth, three other finite element models were developed having a different material combination of the implant. Dorsiflexion, neutral, and plantarflexion positions were considered as applied loading condition, along with muscle force and ligaments. Implant orientation alters the strain distribution in tibia bone. Strain shielding was found to be less in the case of the optimally positioned implant. Apart from the strain, implant orientation also affects implant–bone micromotion, contact pressure, and wear depth. Implant materials have less influence on tibia bone strain and micromotion. However, wear depth was reduced when ceramic and carbon fibre–reinforced polyetheretherketone material combination was used. Proper orientation of the implant is important to reduce the strain shielding. The present result suggested that ceramic can be used as an alternative to metal and carbon fibre–reinforced polyetheretherketone as an alternative to ultra-high molecular weight polyethylene to reduce wear, which would be beneficial for long-term success and fixation of the implant.

Non-linear 3D Evaluation of Different Oral Implant-Abutment Connections

2012 ◽  
Vol 91 (12) ◽  
pp. 1184-1189 ◽  
Author(s):  
P. Streckbein ◽  
R.G. Streckbein ◽  
J.F. Wilbrand ◽  
C.Y. Malik ◽  
H. Schaaf ◽  
...  
Keyword(s):  
Finite Element ◽  
Cone Angle ◽  
Three Dimensional ◽  
Bone Strain ◽  
Finite Element Models ◽  
Implant Abutment ◽  
Non Linear ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

Micro-gaps and osseous overload in the implant-abutment connection are the most common causes of peri-implant bone resorption and implant failure. These undesirable events can be visualized on standardized three-dimensional finite element models and by radiographic methods. The present study investigated the influence of 7 available implant systems (Ankylos, Astra, Bego, Brånemark, Camlog, Straumann, and Xive) with different implant-abutment connections on bone overload and the appearance of micro-gaps in vitro. The individual geometries of the implants were transferred to three-dimensional finite element models. In a non-linear analysis considering the pre-loading of the occlusion screw, friction between the implant and abutment, the influence of the cone angle on bone strain, and the appearance of micro-gaps were determined. Increased bone strains were correlated with small (< 15°) cone angles. Conical implant-abutment connections efficiently avoided micro-gaps but had a negative effect on peri-implant bone strain. Bone strain was reduced in implants with greater wall thickness (Ankylos) or a smaller cone angle (Bego). The results of our in silico study provide a solid basis for the reduction of peri-implant bone strain and micro-gaps in the implant-abutment connection to improve long-term stability.

OPTIMUM EXPANSION AND RESIDUAL CONTACT PRESSURE LEVELS OF HYDRAULICALLY EXPANDED TUBE-TO-TUBESHEET JOINTS

1997 ◽  
Vol 21 (4) ◽  
pp. 415-434 ◽  
Author(s):  
M. Allam ◽  
A. Chaaban ◽  
A. Bazergui
Keyword(s):  
Finite Element ◽  
Residual Stresses ◽  
Contact Pressure ◽  
Heat Exchangers ◽  
Statistical Technique ◽  
Triangular Array ◽  
Finite Element Models ◽  
Steam Generators ◽  
Expansion Process ◽  
Expansion Pressure

Tube-to-tubesheet joints in steam generators and other heat exchangers are now often assembled by means of a hydraulic expansion process that plastically deforms the tubes against the tubesheet and thus creates an interference residual contact pressure between the tube and the tubesheet as well as tensile residual stresses in the tube. A good understanding of both the residual contact pressure and the residual stresses is important for establishing the integrity of the expanded joint. The propose of this paper is to investigate the effect of the level of the expansion pressure on both the residual contact pressure an the maximum tensile residual stresses. A comparison between the 3-D and the axisymmetric Finite Element models for a triangular array tube patterns is presented. An analytical equation is proposed for determining the optimum expansion pressure that provides an acceptable level of residual contact pressure and maximum tensile residual stresses. A statistical technique is also carried out to confirm the validity of the proposed approach.

scholarly journals Influences of Different Implant Material Combinations on the Stress Distribution of the Foot Following Total Ankle Replacement: a Finite Element Analysis

2021 ◽  
Author(s):  
Jian Yu ◽  
Dahang Zhao ◽  
Wen-Ming Chen ◽  
Pengfei Chu ◽  
Shuo Wang ◽  
...  
Keyword(s):  
Finite Element ◽  
Articular Surface ◽  
Reaction Force ◽  
Total Ankle Replacement ◽  
Von Mises Stress ◽  
Cobalt Chromium ◽  
Polyether Ether Ketone ◽  
Implant Material ◽  
Ankle Replacement ◽  
Ether Ketone

Abstract Background A proper combination of implant materials for Total Ankle Replacement (TAR) may reduce stress at the implant and the foot. This study aimed to investigate the biomechanical influences for different implant material combinations using the finite element (FE) method. Methods A validated foot model was modified to simulate TAR with the INBONE II ankle system at the second peak ground reaction force. Six types of materials were used (Ceramic, cobalt–chromium–molybdenum alloy (CoCrMo), Titanium alloy (Ti6Al4V), carbon-fiber-reinforced Polyether-ether-ketone (CFR-PEEK), Polyether-ether-ketone (PEEK), and used ultra-high molecular weight polyethylene (UHMWPE)). Results The von Mises stress at the bearing articular surface decreased with implant stiffness. The combination of CFR-PEEK on UHMWPE presented the lowest stress of 14.82 MPa. A low implant stiffness of the talar component, rather than the bearing, relieved the stress at the resected surface of the talus. Conclusions Soft implant material provided a stress reduction at the bearing and adjacent bones. CFR-PEEK seemed to be a good alternative to implant metal components.

Wear analysis of an automotive window regulator slider

2019 ◽  
Vol 233 (10) ◽  
pp. 1508-1522 ◽  
Author(s):  
Xiaoshuang Xiong ◽  
Lin Hua ◽  
Xiaojin Wan ◽  
Wei Guo ◽  
Can Yang ◽  
...  
Keyword(s):  
Finite Element ◽  
Contact Pressure ◽  
Wear Test ◽  
Wear Depth ◽  
Wear Properties ◽  
Grease Lubrication ◽  
Element Analysis ◽  
Wear Life ◽  
Window Regulator ◽  
Lubrication Condition

The slider, which is made of polyoxymethylene, is the key component of an automotive window regulator. Its function is to guide the window's movement, but it is prone to wear and tear. To reduce noise and improve the wear life of slider, a study of its contact characteristic and the wear life is significant. In this paper, the wear and friction properties of polyoxymethylene under dry sliding condition and grease lubrication condition are investigated using a pin-on-disc apparatus. The complex force conditions of the slider at the normal working condition are studied by a mechanics analysis method. The contact pressure of slider is analyzed by the finite element analysis and the wear of slider is calculated by the proposed wear prediction model. Prediction of the wear life of slider is verified by a window regulator wear experiment. Results show that the value of wear rate of polyoxymethylene under unlubricated condition is much higher than that under lubricated condition. The estimation of wear depth of slider, based on the combination of finite element contact pressure analysis and wear properties of polyoxymethylene, is in accordance with window regulator wear test under unlubricated condition. Besides, the practical wear depth of slider under grease lubrication condition is also in the range of the predicted wear depth of slider under dry and grease lubrication condition.

Finite Element Simulation of Tire-Rim Interface

1989 ◽  
Vol 17 (4) ◽  
pp. 305-325 ◽  
Author(s):  
N. T. Tseng ◽  
R. G. Pelle ◽  
J. P. Chang
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Finite Element Simulation ◽  
Contact Pressure ◽  
Element Model ◽  
Experimental Measurements ◽  
Inflation Pressure ◽  
Interference Fit ◽  
Element Simulation ◽  
Rubber Composite

Abstract A finite element model was developed to simulate the tire-rim interface. Elastomers were modeled by nonlinear incompressible elements, whereas plies were simulated by cord-rubber composite elements. Gap elements were used to simulate the opening between tire and rim at zero inflation pressure. This opening closed when the inflation pressure was increased gradually. The predicted distribution of contact pressure at the tire-rim interface agreed very well with the available experimental measurements. Several variations of the tire-rim interference fit were analyzed.

A Finite Element Analysis of the General Rolling Contact Problem for a Viscoelastic Rubber Cylinder

1988 ◽  
Vol 16 (1) ◽  
pp. 18-43 ◽  
Author(s):  
J. T. Oden ◽  
T. L. Lin ◽  
J. M. Bass
Keyword(s):  
Finite Element ◽  
Variational Principles ◽  
Standing Waves ◽  
Rolling Contact ◽  
Finite Element Models ◽  
Viscoelastic Cylinder ◽  
Element Analysis ◽  
Elastic Rubber ◽  
Frictional Effects ◽  
Rough Foundation

Abstract Mathematical models of finite deformation of a rolling viscoelastic cylinder in contact with a rough foundation are developed in preparation for a general model for rolling tires. Variational principles and finite element models are derived. Numerical results are obtained for a variety of cases, including that of a pure elastic rubber cylinder, a viscoelastic cylinder, the development of standing waves, and frictional effects.

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