scholarly journals Effect of apical portion of T-, sloped L-, and reversed L-closing loops on their force systems

2016 ◽  
Vol 87 (1) ◽  
pp. 104-110 ◽  
Author(s):  
Paiboon Techalertpaisarn ◽  
Antheunis Versluis
Keyword(s):  
Three Dimensional ◽  
Vertical Force ◽  
Element Analysis ◽  
Force System ◽  
Apical Portion ◽  
Beam Elements ◽  
Force Ratio ◽  
Force Systems ◽  
Three Dimensional Models ◽  
Apical Loop

ABSTRACT Objective: To investigate the effect of the position of the apical portion of closing loops on the force system at both loop ends. Materials and Methods: T-loops were compared with backward-sloped L-loops (SL) and reversed L-loops (RL). SL-loops were directed toward the anterior side; RL-loops were directed toward the posterior side. Loop response to loop pulling was determined with finite element analysis at six positions of the apical loop portion for 12-mm interbracket distance and 8-mm loop length and height. Three-dimensional models of the closing loops were created using beam elements with the properties of stainless steel. Loop responses (horizontal load/deflection, vertical force, and moment-to-force ratio) at both loop ends were calculated as well as at 100 g and 200 g activation forces. Results: T-, SL-, and RL-loops with the same position of the apical portion showed approximately the same force system at both loop ends. This behavior was found across the investigated range through which the loops were moved (interbracket center to posterior bracket). Conclusions: The center of the apical portion determined the force system of the closing loops regardless of the position of the loop legs. The centers of the apical portion of the T-, SL-, and RL-loops acted like V-bend positions.

scholarly journals Three-dimensional nonlinear prediction of tooth movement from the force system and root morphology

2020 ◽  
Vol 90 (6) ◽  
pp. 811-822
Author(s):  
Roberto Savignano ◽  
Rodrigo F. Viecilli ◽  
Udochukwu Oyoyo
Keyword(s):  
Tooth Movement ◽  
Three Dimensional ◽  
Cone Beam ◽  
Nonlinear Prediction ◽  
Element Analysis ◽  
Force System ◽  
Force Ratio ◽  
Force Direction ◽  
Force Systems ◽  
The Moment

ABSTRACT Objectives To determine the different impact of moment-to-force ratio (M:F) variation for each tooth and spatial plane and to develop a mathematical model to predict the orthodontic movement for every tooth. Materials and Methods Two full sets of teeth were obtained combining cone-beam computed tomography (CBCT) and optical scans for two patients. Subsequently, a finite element analysis was performed for 510 different force systems for each tooth to evaluate the centers of rotation. Results The center of CROT locations were analyzed, showing that the M:F effect was related to the spatial plane on which the moment was applied, to the force direction, and to the tooth morphology. The tooth dimensions on each plane were mathematically used to derive their influence on the tooth movement. Conclusion This study established the basis for an orthodontist to determine how the teeth move and their axes of resistance, depending on their morphology alone. The movement is controlled by a parameter (k), which depends on tooth dimensions and force system features. The k for a tooth can be calculated using a CBCT and a specific set of covariates.

scholarly journals Comparative Evaluation of Biomechanical Performance of Titanium and Stainless Steel Mini Implants at Different Angulations in Maxilla: A Finite Element Analysis

2019 ◽  
Vol 53 (3) ◽  
pp. 197-205
Author(s):  
Kshitij Hemant Sabley ◽  
Usha Shenoy ◽  
Sujoy Banerjee ◽  
Pankaj Akhare ◽  
Ananya Hazarey ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Computer Aided Design ◽  
Three Dimensional ◽  
Titanium Implant ◽  
Titanium Implants ◽  
Element Analysis ◽  
Mini Implants ◽  
The Difference ◽  
Tractional Forces ◽  
Three Dimensional Models

Objective: To assess and compare the tensions and deformations (stresses and strains) generated after application of two types of forces (traction and torsion) in miniscrews of two different materials (titanium and stainless steel) placed at five different angulations. Materials and Methods: Three-dimensional models of the posterior maxillary area and the mini-implants were constructed using computer-aided design software program (CATIA P3 V5-6 R2015 B26 / 2016; Dassault Systèmes). Titanium and stainless steel materials were used for miniscrews. The area constructed was in between the maxillary second premolar and first molar. The models with mini-implants were inserted at five different angulations (30°, 45°, 60°, 75° and 90°). Torsional and tractional forces were applied on these implants, and the models were solved using ANSYS 10.0. Stress generated in implant and in the cortical and cancellous bones was evaluated and compared at all the five angulations. Results: Stress generated in stainless steel mini-implant during torsional and linear force application was less when compared with titanium mini-implant. Also, stress generated in implants of both materials increased as the angle increased from 30° to 90°. Difference in stress generated by stainless steel implant in the cortical bone for both linear and torsional forces was less when compared with titanium implant, whereas for cancellous bone, the difference was insignificant at all the angles. Conclusion: Irrespective of angles, difference in stress generated in stainless steel implants and titanium implants for both the forces was not significant, and hence, stainless steel implants can be used effectively in a clinical setting.

Thermomechanical Transient Analysis and Conceptual Optimization of a First Stage Bucket

2010 ◽  
Vol 133 (1) ◽  
Author(s):  
Alfonso Campos-Amezcua ◽  
Zdzislaw Mazur-Czerwiec ◽  
Armando Gallegos-Muñoz
Keyword(s):  
Transient Analysis ◽  
Computational Models ◽  
Flow Analysis ◽  
Three Dimensional ◽  
Thermomechanical Analysis ◽  
Element Analysis ◽  
Simulation Techniques ◽  
Calculated Stress ◽  
Three Dimensional Models ◽  
Almost All

This paper presents a thermomechanical analysis of a first stage bucket during a gas turbine startup. This analysis uses two simulation techniques, computational fluid dynamics (CFD) for the conjugate heat transfer and flow analysis, and finite element analysis (FEA) for the thermostructural analysis. Computational three-dimensional models were developed using two commercial codes, including all elements of the real bucket to avoid geometric simplifications. An interface was developed to transfer the three-dimensional behavior of bucket temperatures during turbine startup from CFD analysis to subsequent FEA analysis, imposing them as a thermal load. This interface virtually integrates the computational models, although they have different grids. The results of this analysis include temperature evolution and related stresses, as well as the thermomechanical stresses and zones where they are present. These stresses are dominated by thermal mechanisms, so a new temperature startup curve is proposed where the maximum calculated stress decline around 100 MPa, and almost all stresses are lower throughout the transient analysis. The results are compared with experimental data reported in the literature obtaining acceptable approximation.

scholarly journals Mechanical Force System of Double Key Loop With Finite Element Analysis 

2020 ◽  
Author(s):  
Jiali Liu ◽  
Duanqiang Zhang ◽  
Linyu Xu ◽  
Senxin Cai ◽  
Jinquan Guo ◽  
...  
Keyword(s):  
Finite Element ◽  
Element Model ◽  
Vertical Force ◽  
Element Analysis ◽  
Force System ◽  
Anterior Teeth ◽  
Lower Magnitude ◽  
Type 3

Abstract Background: The mechanics of double key loop (DKL) was not well defined and this finite element study was designed to explore its force system.Methods: Simplified 3-dimensional finite element model of single and double key loops with archwire between lateral incisor and second premolar was established in Ansys Workbench. Activation in Type-1 (retraction at distal end), Type-2 (retraction at distal key) and Type-3 (Type-2 plus ligation between keys) were simulated. The vertical force, load/deflection ratio and moment/force ratio of stainless steel and TMA loops were calculated and compared.Results: Double key loop generated about 40% force of single key loop. Type-2 loading of DKL showed higher L/D ratio than in Type-1 loading with similar M/F ratio. Type-3 loading of DKL showed the highest M/F ratio with similar L/D ratio as single key loop. The M/F ratio in Type-3 loading increased with the decrease of retraction force. DKL of TMA produced about 40% of force and moment compared to those of SS in all loading types. When activated at equal distance bellow 1mm, the M/F ratio of SS and TMA DKL with equal preactivation angle were almost the same. Conclusion: M/F ratio on anterior teeth increases with preactivation angle and deactivation of DKL. M/F ratio at certain distance of activation depends mainly on preactivation angle instead of wire material. TMA is recommended as substitute of SS in DKL for lower magnitude of force.

scholarly journals Effects of Different Positions and Angles of Implants in Maxillary Edentulous Jaw on Surrounding Bone Stress under Dynamic Loading: A Three-Dimensional Finite Element Analysis

2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Xiaqing Liu ◽  
Fang Pang ◽  
Ying Li ◽  
Hui Jia ◽  
Xiaohua Cui ◽  
...  
Keyword(s):  
Cortical Bone ◽  
Dynamic Loading ◽  
Three Dimensional ◽  
Element Analysis ◽  
Posterior Teeth ◽  
Dimensional Finite Element ◽  
Three Dimensional Models ◽  
Three Dimensional Finite Element ◽  
Edentulous Jaws ◽  
Surrounding Bone

Purpose. To evaluate the effects of different placements of mesial implants and different angles of distant implants in maxillary edentulous jaws on the stress on the implant and the surrounding bone tissue under dynamic loading. Materials and Methods. Cone beam computed tomography was used to acquire images of maxillary edentulous jaws. Using Mimics 17.0, Geomagic, and Unigraphics NX8.5 software, three-dimensional models were established: two mesial implants were placed vertically in the anterior region of the maxilla (bilateral central incisor, lateral incisor, and canine), and two distant implants were placed obliquely in the bilateral second premolar area at different inclined angles (15°, 30°, and 45°). The established models were designated I–IX. The models were subjected to dynamic load using Abaqus 6.12, with the working side posterior teeth loading of 150 N and simulation cycle of 0.875 s. Results. During the second to fourth phases of the mastication cycle, the stress was mainly concentrated on the neck of the distal implant. The stress of the distal implants was greater than that of mesial implants. Stress levels peaked in the third stage of the cycle. The stress of the distal cortical bone of distal implant of Model I reached the maximum of 183.437 MPa. The stress of the distal cortical bone and cancellous bone of distal implant of Model VIII represented the minima (62.989 MPa and 17.186 MPa, respectively). Conclusions. Our models showed optimal stress reductions when the mesial implants were located in the canine region and the distal implants tilted 30°.

scholarly journals The Design and Analysis of Internally Stiffened GFRP Tubular Decks—A Sustainable Solution

2018 ◽  
Vol 10 (12) ◽  
pp. 4538 ◽  
Author(s):  
Yeou-Fong Li ◽  
Habib Meda ◽  
Walter Chen
Keyword(s):  
Finite Element ◽  
Life Cycle Cost ◽  
Three Dimensional ◽  
Torsional Stiffness ◽  
Thin Wall ◽  
Low Carbon ◽  
Element Analysis ◽  
Finite Element Software ◽  
Deck Panels ◽  
Three Dimensional Models

The aim of this paper was to find an optimal stiffener configuration of thin-wall tubular panels made by glass fiber reinforced polymer (GFRP) composite material, which is a low carbon emission, low life cycle cost, and sustainable material. Finite-element analysis (FEA) was used to investigate the flexural and torsional stiffness of various internally stiffened sections of thin-wall GFRP decks. These decks consist of internally stiffened tubular profiles laid side by side and bonded together with epoxy to ensure the panel acts as an assembly. Three-dimensional models of the seven proposed decks were assembled with tubular profiles of different stiffener patterns. First, the non-stiffened tube profile was tested experimentally to validate the parameters used in the subsequent numerical analysis. Then, the finite element software, ANSYS, was used to simulate the flexural and torsional behavior of the decks with different stiffener patterns under bending and torsional loads. The decks with stiffener patterns such as “O” type, “V” type, and “D” type were found to be the most effective in bending. For torsion, there was a distinct tendency for deck panels with closed shaped stiffener patterns to perform better than their counterparts. Overall, the “O” type deck panel was an optimal stiffener configuration.

The Simulation of Rolling Process of Wire with Y-Type Roller

2014 ◽  
Vol 602-605 ◽  
pp. 709-712
Author(s):  
Jin Hong Ma ◽  
Bin Tao ◽  
Xiao Han Yao
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Rolling Mill ◽  
Three Dimensional ◽  
Rolling Process ◽  
Stress And Strain ◽  
Analysis Software ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Three Dimensional Models

Y-Type rolling mill with three roller is a new kind of wire mill.The three-dimensional models of rolling are established by Pro/E. Based on the finite element analysis software ANSYS/LS-DYNA, the rolling process of wire by Y-type rollers is simulated. The rolling piece movement is analysed. Stress and strain of Y-type roller are also analysed.

Finite Element Analysis and Its Application in Oral Surgery Research

2010 ◽  
pp. 159-170
Author(s):  
Mercedes Gallas
Keyword(s):  
Finite Element ◽  
Oral Surgery ◽  
Three Dimensional ◽  
Element Analysis ◽  
Biomechanical Behavior ◽  
Force Systems ◽  
Surgery Research ◽  
Miniplate Osteosynthesis ◽  
Virtual Modeling ◽  
Regional Stresses

The Finite Element Method (FEM) is a widely applied mathematical model that permit us to know the biomechanical behavior of the human mandible in various clinical situations under physiological and standardized trauma conditions. The three-dimensional FEM provides to simulate force systems applied and allows analysis of the response of the jawbone to the loads in 3D space. Clinical extrapolations from FEM may not give absolute values but they will provide detailed description of biomechanical pattern and a prediction of regional stresses distribution. This virtual modeling is useful to choose the most efficient localization and design of miniplate osteosynthesis and to test new biomaterials.

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