Comparison of Stresses in Four Modular Total Knee Arthroplasty Prosthesis Designs

2016 ◽  
Vol 5 (2) ◽  
pp. 1-16
Author(s):  
Ahilan Anantha Krishnan ◽  
Rupesh Ghyar ◽  
Bhallamudi Ravi
Keyword(s):  
Yield Strength ◽  
Mechanical Performance ◽  
Three Dimensional ◽  
Compressive Load ◽  
Von Mises Stress ◽  
Dimensional Finite Element ◽  
Tibial Insert ◽  
Modular Prostheses ◽  
Von Mises ◽  
Three Dimensional Finite Element

The current study, compares the mechanical performance of four modular TKA prostheses based on von Mises stress distribution in the tibial insert. Three-dimensional finite element (FE) models of a cruciate retaining type modular prosthesis and three posterior stabilized (PS) type modular prostheses namely: anterior slide, modular post and double cam, were developed. A compressive load of 2600 N was applied to the FE models at flexion angles of 00, 150, 300, 600 and 900. Von Mises stress was evaluated on all the modular parts of the prostheses and compared with the yield strength of the corresponding material. Von Mises stress in all the parts were below the yield strength of their corresponding material except for tibial insert of anterior slide design at high flexion angle. Von Mises stress above the yield strength in the tibial insert of anterior slide design, was due to edge loading in the post and it demonstrates the likelihood of mechanical failure by delamination type of wear.

A comparative study between zirconia and titanium abutments on the stress distribution in parafunctional loading: A 3D finite element analysis

2020 ◽  
Vol 28 (6) ◽  
pp. 603-613 ◽  
Author(s):  
Efe Can Sivrikaya ◽  
Mehmet Sami Guler ◽  
Muhammed Latif Bekci
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Von Mises Stress ◽  
Principal Stresses ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
3D Fea ◽  
Von Mises ◽  
Three Dimensional Finite Element

BACKGROUND: Zirconia has become a popular biomaterial in dental implant systems because of its biocompatible and aesthetic properties. However, this material is more fragile than titanium so its use is limited. OBJECTIVES: The aim of this study was to compare the stresses on morse taper implant systems under parafunctional loading in different abutment materials using three-dimensional finite element analysis (3D FEA). METHODS: Four different variations were modelled. The models were created according to abutment materials (zirconia or titanium) and loading (1000 MPa vertical or oblique on abutments). The placement of the implants (diameter, 5.0 × 15 mm) were mandibular right first molar. RESULTS: In zirconia abutment models, von Mises stress (VMS) values of implants and abutments were decreased. Maximum and minimum principal stresses and VMS values increased in oblique loading. VMS values were highest in the connection level of the conical abutments in all models. CONCLUSIONS: Using conical zirconia abutments decreases von Mises stress values in abutments and implants. However, these values may exceed the pathological limits in bruxism patients. Therefore, microfractures may be related to the level of the abutment.

scholarly journals A three - dimensional finite element study on the stress distribution pattern of two prosthetic abutments for external hexagon implants

2013 ◽  
Vol 07 (04) ◽  
pp. 484-491 ◽  
Author(s):  
Wagner Moreira ◽  
Caio Hermann ◽  
Jucélio Tomás Pereira ◽  
Jean Anacleto Balbinoti ◽  
Rodrigo Tiossi
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Three Dimensional ◽  
Von Mises Stress ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
3D Fea ◽  
The One ◽  
Von Mises ◽  
Three Dimensional Finite Element

ABSTRACT Objective: The purpose of this study was to evaluate the mechanical behavior of two different straight prosthetic abutments (one- and two-piece) for external hex butt-joint connection implants using three-dimensional finite element analysis (3D-FEA). Materials and Methods: Two 3D-FEA models were designed, one for the two-piece prosthetic abutment (2 mm in height, two-piece mini-conical abutment, Neodent) and another one for the one-piece abutment (2 mm in height, Slim Fit one-piece mini-conical abutment, Neodent), with their corresponding screws and implants (Titamax Ti, 3.75 diameter by 13 mm in length, Neodent). The model simulated the single restoration of a lower premolar using data from a computerized tomography of a mandible. The preload (20 N) after torque application for installation of the abutment and an occlusal loading were simulated. The occlusal load was simulated using average physiological bite force and direction (114.6 N in the axial direction, 17.1 N in the lingual direction and 23.4 N toward the mesial at an angle of 75° to the occlusal plan). Results: The regions with the highest von Mises stress results were at the bottom of the initial two threads of both prosthetic abutments that were tested. The one-piece prosthetic abutment presented a more homogeneous behavior of stress distribution when compared with the two-piece abutment. Conclusions: Under the simulated chewing loads, the von Mises stresses for both tested prosthetic-abutments were within the tensile strength values of the materials analyzed which thus supports the clinical use of both prosthetic abutments.

Optimization of Adhesively Bonded Spar-Wingskin Joints of Laminated FRP Composites Subjected to Pull-Off Load: A Critical Review

2020 ◽  
Vol 8 (1) ◽  
pp. 29-46
Author(s):  
S. Rakshe ◽  
S. V. Nimje ◽  
S. K. Panigrahi
Keyword(s):  
Three Dimensional ◽  
Von Mises Stress ◽  
Geometrical Parameters ◽  
Adhesively Bonded ◽  
Element Analysis ◽  
Frp Composites ◽  
Dimensional Finite Element ◽  
Materials Used ◽  
Von Mises ◽  
Three Dimensional Finite Element

A review on optimization of adhesively bonded spar-wingskin joint (SWJ) of laminated fiber reinforced polymer (FRP) composites subjected to pull-off load is presented in this article using three-dimensional finite element analysis. Von Mises stress components have been computed across the width of joint at different interfaces viz. load coupler-spar, and load coupler-wingskin interfaces. Further, the weight of SWJ structure is considered as the objective function which needs to be minimized for optimization. In the first step, the material and lamination scheme of the FRP composite materials used for SWJ are optimized, and, in the second step, the geometrical parameters have been optimized on the basis of minimum von Mises stress and weight. Further, the effects of the material, lamination scheme, and geometrical parameters on the von Mises stress and weight have been validated using the Analysis of Variance (ANOVA) approach as prescribed by the Taguchi method. The results show that the material and spar thickness are the most significant factors influencing von Mises stress. The weight analysis reveals that there is a significant effect of change in material and wingskin thickness on SWJ performance. Suitable design recommendations have been made for SWJ in terms of material, lamination scheme and geometrical parameters.

scholarly journals Effect of Maxillary Implants Region and Loading Condition in the Stress Distribution of Implant-Supported Full-Arch Prosthesis: 3D-FEA

2021 ◽  
Author(s):  
Mateus Favero Barra Grande ◽  
Marcelo Lucchesi Teixeira ◽  
André Antônio Pelegrine ◽  
Guilherme Da Rocha Scalzer Lopes ◽  
Julio Ferraz Campos ◽  
...  
Keyword(s):  
Finite Element ◽  
Dental Implants ◽  
Dental Treatment ◽  
Three Dimensional ◽  
Von Mises Stress ◽  
Cobalt Chromium ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
Von Mises ◽  
Three Dimensional Finite Element

The effect of the different dental implants positioning region on the stress performance of the implant-supported prosthesis is not yet clear. This study evaluated the dental treatment with six dental implants in three different models and three different occlusal loading conditions, in terms of the biomechanical response of implants, prosthetic screw and maxilla, using three-dimensional finite element analysis. The finite element models were modelled containing external hexagon implants, as well as a Cobalt-Chromium superstructure. Three types of loads were applied: in the area of ​​the central incisors, first premolar and in the second molars. For the finite element simulations, the von-Mises stress peaks in the implant and in the surrounding cortical bone were analyzed. All recorded results reported higher values ​​for the implant-supported prosthesis in group C compared to the groups A and B. The highest stress values, ​​regardless the evaluated model, was in the prosthesis in group C and in screws, the smallest were in group A.

Simplified Numerical Model for Rapid Design of AF Module Spring Shape Parameters

2017 ◽  
Vol 34 (5) ◽  
pp. 591-600
Author(s):  
D. S. Liu ◽  
C. J. Lu ◽  
S. H. Chen ◽  
C. S. Liu ◽  
T. W. Liao
Keyword(s):  
Reaction Force ◽  
Three Dimensional ◽  
Voice Coil Motor ◽  
Von Mises Stress ◽  
Structural Method ◽  
Spring Stiffness ◽  
Shape Parameters ◽  
Dimensional Finite Element ◽  
Von Mises ◽  
Three Dimensional Finite Element

AbstractThe autofocusing (AF) performance of cell phone cameras is critically dependent on the design of the voice-coil motor (VCM) used to drive the lens module. Also, the metal springs in the AF module should combine high stiffness with a good actuation response and a light weight. The present study utilizes a reverse engineering approach to construct three-dimensional finite element models of the top and bottom springs in the VCM mechanism. Simulations are then performed to investigate the von Mises stress distribution and stiffness characteristics of the two springs given horizontal and vertical orientations of the AF module, respectively. In performing the simulations, the actuation force is computed using two different analysis methods, namely a simplify structure method and a coupled electromagnetic-structural method. It is shown that the simplify structure method has the advantages of a lower computational complexity and a more comprehensive modeling capability. A further series of simulations is thus to examine the effects of the spring shape parameters on the reaction force developed by the spring stiffness. The results show that the spring stiffness increases with an increasing thickness and a decreasing rib length. The simulation results obtained for different spring shape parameter settings are summarized in the form of a parameter design chart for predicting the reaction force given known values of the spring rib length and spring thickness.

Finite Element Analysis for the Mega Columns for XRL West Kowloon Terminus

2013 ◽  
Vol 405-408 ◽  
pp. 1139-1143
Author(s):  
Wei Su ◽  
Ying Sun ◽  
Shi Qing Huang ◽  
Ren Huai Liu
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Parametric Design ◽  
Three Dimensional ◽  
Element Model ◽  
Von Mises Stress ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
Von Mises ◽  
Three Dimensional Finite Element

Using ANSYS parametric design language, a three-dimensional finite element model is developed to analyze the stress distribution and the strength of the mega columns for XRL West Kowloon Terminus. The detailed von Mises stress distribution in each column, vertical stiffener plates and the diaphragm plates is obtained. From the analysis, the phenomenon of stress concentration is obvious in both upper and lower diaphragm plates. The local value of von Mises stress in them is higher than the yield stress value, which must be avoided by more detailed local structural design.

scholarly journals Finite Element Analysis of Dental Implants with Zirconia Crown Restorations: Conventional Cement-Retained vs. Cementless Screw-Retained

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2666
Author(s):  
Jae-Hyun Lee ◽  
Ho Yeol Jang ◽  
Su Young Lee
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Von Mises Stress ◽  
Stress Distributions ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
Von Mises ◽  
Three Dimensional Finite Element ◽  
Oblique Load ◽  
Surrounding Bone

The present study was designed to compare the stress distributions in two restoration types of implants and the surrounding bone. The first restoration type was a conventional cement-retained zirconia crown, and the second was a novel cementless screw-retained zirconia crown with a base abutment. A three-dimensional finite element method was used to model the implants, restorations, and supporting bone. A comparative study of the two implants was performed under two masticatory loads: a vertical load of 100 N and a 30-degree oblique load of 100 N. Under both loading conditions, the maximum von Mises stress and strain values in the implant and supporting bone were higher in the conventional cement-retained restoration model than in the cementless screw-retained model. In terms of stress distribution, the cementless screw-retained zirconia crown with base abutment may be considered a superior restoration option compared to the conventional cement-retained zirconia crown.

Numerical Simulation for Stress Distribution of Bones and Bone Plate Using Finite Element Method

2012 ◽  
Vol 197 ◽  
pp. 93-97 ◽  
Author(s):  
Wen Zhi Zhao ◽  
Hong Jiang ◽  
Sheng Wei He ◽  
Lu Zhang ◽  
Xue Gang Sun
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Element Model ◽  
Integrated System ◽  
Bone Plate ◽  
Von Mises Stress ◽  
Dimensional Finite Element ◽  
Von Mises ◽  
Three Dimensional Finite Element ◽  
Bone Section

A three-dimensional finite element model is developed to simulate the integrated system which consists of the fractured bone (femur), bone plate and stabilization screw by using the ANSYS software. The stress and strain distribution of the integrated system is investigated. The numerical model simulates a patient’s imperfect walking under the assumption that the fractured bone is not able to support any load and all body weight was burden by bone plate in fractured bone section. The simulation results reveal that the maximum Von Mises stress on bone plate is much less than yield strength and fatigue strength of Titanium alloy.

scholarly journals Stress Distribution on the Prosthetic Screws in the All-on-4 Concept: A Three-Dimensional Finite Element Analysis

2020 ◽  
Vol 46 (1) ◽  
pp. 3-12
Author(s):  
Ji-Hyeon Oh ◽  
Young-Seong Kim ◽  
Joong Yeon Lim ◽  
Byung-Ho Choi
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Distribution ◽  
Three Dimensional ◽  
Von Mises Stress ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
Edentulous Patients ◽  
Von Mises ◽  
Three Dimensional Finite Element

The all-on-4 concept, which is used to rehabilitate edentulous patients, can present with mechanical complications such as screw loosening and fracture. The purpose of this study was to evaluate the stress patterns induced in the prosthetic screws by the different prosthetic screw and abutment designs in the all-on-4 concept using finite element analysis. Von Mises stress values on 6 groups of each screw type, including short and narrow screw, short abutment; short and wide screw, short abutment; long and wide screw, short abutment; short and narrow screw, long abutment; short and wide screw, long abutment; and long and wide screw, long abutment, were compared under a cantilever loading of 200 N that was applied on the farther posterior to the position of the connection between the distal implant and the metal framework. Posterior prosthetic screws showed higher stress values than anterior prosthetic screws. The stress values in posterior prosthetic screws decreased as the length and diameter increased. In conclusion, the long and wide screw design offers advantages in stress distribution when compared with the short and narrow design.

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