Three-Dimensional Finite Element Analysis of a Simplified Compression Plate Fixation System

1984 ◽  
Vol 106 (4) ◽  
pp. 295-301 ◽  
Author(s):  
E. J. Cheal ◽  
W. C. Hayes ◽  
A. A. White ◽  
S. M. Perren
Keyword(s):  
Finite Element ◽  
Strain Gage ◽  
Composite Beam ◽  
Plate Fixation ◽  
Three Dimensional ◽  
Beam Theory ◽  
Fracture Site ◽  
Test Model ◽  
Element Analysis ◽  
Compression Plate

A three-dimensional, linear finite element model was generated for an intact plexiglass tube with an attached six-hole stainless steel compression plate. We examined external forces representing axial, off-center axial, and four-point bending, along with superimposed plate and screw pretension. Strain gage experiments were conducted to test model validity and the finite element results were contrasted to a composite beam theory solution. Excellent correspondence was observed between finite element and strain gage data for the most significant strain components. Composite beam theory tended to overestimate the neutral axis shift which results from plate application. The model also demonstrated fracture site distraction due to plate pretension, and the tendency for outer screw failure for the combination of bending-closed with a preload in the plate and screws.

scholarly journals Is Perpendicular Double Two-Hole Plates Fixation Superior to Single Four-Hole Plate Fixation to Treat Mandibular Symphysis Fracture?—A Finite Element Study

2021 ◽  
Vol 11 (18) ◽  
pp. 8629
Author(s):  
Li-Ren Chang ◽  
Ya-Pei Hou ◽  
Ting-Sheng Lin
Keyword(s):  
Finite Element ◽  
Plate Fixation ◽  
Mandibular Condyle ◽  
Fracture Site ◽  
Von Mises Stress ◽  
Stress Concentrations ◽  
Element Analysis ◽  
Mandibular Symphysis ◽  
Lower Border ◽  
Von Mises

The effectiveness of a single four-hole plate (S4HP), perpendicularly oriented four-hole and two-hole plate (Per4H2HP), and perpendicularly oriented double two-hole plate (PerD2HP) for the fixation of a mandibular fracture was studied. A finite element analysis of the mandibular symphysis fractures treated with S4HP, Per4H2HP, and PerD2HP was performed. All surface nodes were fixed in the mandibular condyle region and occlusal muscle forces were applied. The maximal von Mises stress (MaxVMS) values of the plates, screws and screw holes were investigated. The displacement of the fracture site on the lower border of the mandibular symphysis was recorded. The displacement on the lower border of the fracture sites in the S4HP group was greater than that in the Per4H2HP group and the PerD2HP group. There was no eversion at the fracture site among all groups. Both the S4HP and Per4H2HP groups showed stress concentrations on the screws close to the fracture site. The MaxVMS increased when the number of screw holes on the mandibular anterior lower border decreased. The displacement of the fracture site and eversion with Per4H2HP and PerD2HP were far lower than those with S4HP. PerD2HP is a stable and green fixation technique for mandibular symphysis fractures.

Precision Machines: Diagnostics of Vibration Through Modal and Finite Element Analysis

1991 ◽  
Author(s):  
V. Prakash ◽  
R. J. Montague
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Three Dimensional ◽  
Element Model ◽  
Test Model ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
Structure Correlation ◽  
Three Dimensional Finite Element ◽  
Precision Machines

Abstract This paper presents the diagnostics of the effects of vibration on the precise placement of electronic components in a surface mount assembly process. Experimental Modal Analysis using present day software/hardware as well as a three dimensional finite element model are performed on the machine structure. Correlation between the experiment and finite element model are also performed and the strength of using the finite element model as a test model for contemplating any design alterations are presented.

scholarly journals A comparative biomechanical analysis of suprapectineal and infrapectineal fixation on acetabular anterior column fracture by finite element modeling

2019 ◽  
Author(s):  
MEHMET YÜCENS ◽  
KADİR BAHADIR ALEMDAROĞLU ◽  
AHMET ÖZMERİÇ ◽  
SERKAN İLTAR ◽  
AHMET ÖZGÜR YILDIRIM ◽  
...  
Keyword(s):  
Finite Element ◽  
Plate Fixation ◽  
Three Dimensional ◽  
Fracture Line ◽  
Biomechanical Analysis ◽  
Vertical Shear ◽  
Anterior Column ◽  
Fixation Method ◽  
Stable Fixation ◽  
Element Analysis

Background: The aim of this study is to compare the stability and implant stresses of suprapectineal plate with infrapectineal plate in three subconfigurations of the screw types. Methods: The stabilities of different fixation methods were compared by finite-element analysis on six models. Three infrapectineal models and three suprapectineal models each with locked, unlocked or combined screws were employed. Three-dimensional finite element stress analysis was performed by using isotropic materials with a load of 2.3 kN applied at standing positions. Motion at the fracture line was measured on four different points that are located at pubic and iliac side of the fracture line. Results: Infrapectineal plate fixation with unlocked screws was found to be the most stable fixation method with 0.006 mm displacement of fragments in all axes at standing positions. Suprapectineal unlocked method was found to be the most unstable in standing positions with maximum distraction values of 0.46 mm vertical shear movement in x-axis, -0.14 mm distraction in y-axis and -0.33 mm lateral shear in z-axis. Conclusions: To our results infrapectineal unlocked plate supplies the most stable fixation with least implant stress in contrary to the suprapectineal unlocked plate, which has the lowest stability and highest implant stresses. Keywords: Acetabular fracture; anterior column; suprapectineal; infrapectineal; fixation; finite element.

Fixation of humeral intercondylar fractures using a lateral plate in 14 dogs supported by finite element analysis of repair

2007 ◽  
Vol 20 (04) ◽  
pp. 285-290 ◽  
Author(s):  
D. P. Comiskey ◽  
B. Mac Donald ◽  
C. B. Garvan ◽  
W. T. Mc Cartney
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Plate Fixation ◽  
Distal Humerus ◽  
Fracture Site ◽  
Fixation Method ◽  
Fe Modelling ◽  
Lateral Plate ◽  
Element Analysis ◽  
Micro Motion

SummaryFourteen Spaniels that presented with an intercondylar fracture of the distal humerus were managed using a lateral plate and an additional pin in twelve cases. Fixation of the fracture was achieved using a plate applied laterally which incorporated the transcondylar lag screw in the most distal hole. Of the 14 cases, two had poor results, one of which was a bilateral case, whilst the remaining 12 cases had good or very good results with only occasional stiffness or lameness. Finite element (FE) modelling of a distal humerus was generated, and loading of fracture repairs using a lateral plate and caudal plate was completed in a comparative study to determine which fixation method resisted micro-motion most effectively. Finite element analysis revealed that the lateral plate fixation provided significantly more resistance to micro movement at the fracture site that the caudal plate fixation, with 40% more micro-motion in the latter.

scholarly journals On Modeling the Bending Stiffness of Thin Semi-Circular Flexure Hinges for Precision Applications

Actuators ◽  
2018 ◽  
Vol 7 (4) ◽  
pp. 86 ◽  
Author(s):  
Mario Torres Melgarejo ◽  
Maximilian Darnieder ◽  
Sebastian Linß ◽  
Lena Zentner ◽  
Thomas Fröhlich ◽  
...  
Keyword(s):  
Finite Element ◽  
Accurate Determination ◽  
Three Dimensional ◽  
Beam Theory ◽  
Element Model ◽  
Bending Stiffness ◽  
Analytical Models ◽  
Element Analysis ◽  
Flexure Hinges ◽  
Wide Range

Compliant mechanisms based on flexure hinges are widely used in precision engineering applications. Among those are devices such as precision balances and mass comparators with achievable resolutions and uncertainties in the nano-newton range. The exact knowledge of the mechanical properties of notch hinges and their modeling is essential for the design and the goal-oriented adjustment of these devices. It is shown in this article that many analytical equations available in the literature for calculating the bending stiffness of thin semi-circular flexure hinges cause deviations of up to 12% compared to simulation results based on the three-dimensional finite element model for the considered parameter range. A close examination of the stress state within the loaded hinge reveals possible reasons for this deviation. The article explains this phenomenon in detail and shows the limitations of existing analytical models depending on specific geometric ratios. An accurate determination of the bending stiffness of semi-circular flexure hinges in a wide range of geometric parameters without the need for an elaborate finite element analysis is proposed in form of FEM-based correction factors for analytical equations referring to Euler-Bernoulli’s beam theory.

scholarly journals Biomechanical Property of a Newly Designed Assembly Locking Compression Plate: Three-Dimensional Finite Element Analysis

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Jiang-Jun Zhou ◽  
Min Zhao ◽  
Da Liu ◽  
Hai-Ying Liu ◽  
Cheng-Fei Du
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Maximum Stress ◽  
Three Dimensional ◽  
Locking Compression Plate ◽  
Bone Block ◽  
Element Analysis ◽  
Compression Plate ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

In this study, we developed and validated a refined three-dimensional finite element model of middle femoral comminuted fracture to compare the biomechanical stability after two kinds of plate fixation: a newly designed assembly locking compression plate (NALCP) and a locking compression plate (LCP). CT data of a male volunteer was converted to middle femoral comminuted fracture finite element analysis model. The fracture was fixated by NALCP and LCP. Stress distributions were observed. Under slow walking load and torsion load, the stress distribution tendency of the two plates was roughly uniform. The anterolateral femur was the tension stress area, and the bone block shifted toward the anterolateral femur. Maximum stress was found on the lateral border of the number 5 countersink of the plate. Under a slow walking load, the NALCP maximum stress was 2.160e+03 MPa and the LCP was 8.561e+02 MPa. Under torsion load, the NALCP maximum stress was 2.260e+03 MPa and the LCP was 6.813e+02 MPa. Based on those results of finite element analysis, the NALCP can provide adequate mechanical stability for comminuted fractures, which would help fixate the bone block and promote bone healing.

Effects of occlusal scheme on All-on-Four abutments, screws and prostheses: A three-dimensional finite element study

2020 ◽  
Author(s):  
Nurullah Türker ◽  
Hümeyra Tercanlı Alkış ◽  
Steven J Sadowsky ◽  
Ulviye Şebnem Büyükkaplan
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Good Prognosis ◽  
Von Mises Stress ◽  
Element Analysis ◽  
Group Function ◽  
Occlusal Contact ◽  
Maximum Deformation ◽  
Contact Points ◽  
Von Mises

An ideal occlusal scheme plays an important role in a good prognosis of All-on-Four applications, as it does for other implant therapies, due to the potential impact of occlusal loads on implant prosthetic components. The aim of the present three-dimensional (3D) finite element analysis (FEA) study was to investigate the stresses on abutments, screws and prostheses that are generated by occlusal loads via different occlusal schemes in the All-on-Four concept. Three-dimensional models of the maxilla, mandible, implants, implant substructures and prostheses were designed according to the All-on-Four concept. Forces were applied from the occlusal contact points formed in maximum intercuspation and eccentric movements in canine guidance occlusion (CGO), group function occlusion (GFO) and lingualized occlusion (LO). The von Mises stress values for abutment and screws and deformation values for prostheses were obtained and results were evaluated comparatively. It was observed that the stresses on screws and abutments were more evenly distributed in GFO. Maximum deformation values for prosthesis were observed in the CFO model for lateral movement both in the maxilla and mandible. Within the limits of the present study, GFO may be suggested to reduce stresses on screws, abutments and prostheses in the All-on-Four concept.

Towards Predicting Relative Belt Edge Endurance With the Finite Element Method

1990 ◽  
Vol 18 (4) ◽  
pp. 216-235 ◽  
Author(s):  
J. De Eskinazi ◽  
K. Ishihara ◽  
H. Volk ◽  
T. C. Warholic
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Three Dimensional ◽  
The Finite Element Method ◽  
Shear Deformations ◽  
Element Analysis ◽  
Vertical Loading ◽  
Predicted Values ◽  
Element Method

Abstract The paper describes the intention of the authors to determine whether it is possible to predict relative belt edge endurance for radial passenger car tires using the finite element method. Three groups of tires with different belt edge configurations were tested on a fleet test in an attempt to validate predictions from the finite element results. A two-dimensional, axisymmetric finite element analysis was first used to determine if the results from such an analysis, with emphasis on the shear deformations between the belts, could be used to predict a relative ranking for belt edge endurance. It is shown that such an analysis can lead to erroneous conclusions. A three-dimensional analysis in which tires are modeled under free rotation and static vertical loading was performed next. This approach resulted in an improvement in the quality of the correlations. The differences in the predicted values of various stress analysis parameters for the three belt edge configurations are studied and their implication on predicting belt edge endurance is discussed.

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