scholarly journals Differences in the force system delivered by different beta-titanium wires in elaborate designs

2015 ◽  
Vol 20 (6) ◽  
pp. 89-96 ◽  
Author(s):  
Renato Parsekian Martins ◽  
Sergei Godeiro Fernandes Rabelo Caldas ◽  
Alexandre Antonio Ribeiro ◽  
Luís Geraldo Vaz ◽  
Roberto Hideo Shimizu ◽  
...  
Keyword(s):  
Testing Machine ◽  
Objective Evaluation ◽  
Neutral Position ◽  
Force System ◽  
Beta Titanium ◽  
Force Systems ◽  
Initial Activation ◽  
The Moment ◽  
Fluorescence Spectrometer ◽  
Similar Force

Abstract Objective: Evaluation of the force system produced by four brands of b-Ti wires bent into an elaborate design. Methods: A total of 40 T-loop springs (TLS) hand-bent from 0.017 x 0.025-in b-Ti were randomly divided into four groups according to wire brand: TMATM(G1), BETA FLEXYTM (G2), BETA III WIRETM (G3) and BETA CNATM (G4). Forces and moments were recorded by a moment transducer, coupled to a digital extensometer indicator adapted to a testing machine, every 0.5 mm of deactivation from 5 mm of the initial activation. The moment-to-force (MF) ratio, the overlapping of the vertical extensions of the TLSs and the load-deflection (LD) ratio were also calculated. To complement the results, the Young's module (YM) of each wire was determined by the slope of the load-deflection graph of a tensile test. The surface chemical composition was also evaluated by an energy dispersive X-ray fluorescence spectrometer. Results: All groups, except for G2, produced similar force levels initially. G3 produced the highest LD rates and G1 and G4 had similar amounts of overlap of the vertical extensions of the TLSs in "neutral position". G1 and G3 delivered the highest levels of moments, and G2 and G3 produced the highest MF ratios. b-Ti wires from G3 produced the highest YM and all groups showed similar composition, except for G2. Conclusion: The four beta-titanium wires analyzed produced different force systems when used in a more elaborate design due to the fact that each wire responds differently to bends.

scholarly journals Stability of beta-titanium T-loop springs preactivated by gradual curvature

2017 ◽  
Vol 22 (6) ◽  
pp. 61-67 ◽  
Author(s):  
Sergei Godeiro Fernandes Rabelo Caldas ◽  
Renato Parsekian Martins ◽  
Marcela Emílio de Araújo ◽  
Marília Regalado Galvão ◽  
Roberto Soares da Silva Júnior ◽  
...  
Keyword(s):  
Testing Machine ◽  
Relaxation Methods ◽  
Force System ◽  
Beta Titanium ◽  
Gradual Deformation ◽  
Evaluation Group ◽  
Force Moment ◽  
Initial Activation ◽  
Over Time ◽  
Group 1

ABSTRACT Objective: Evaluate changes in the force system of T-Loop Springs (TLS) preactivated by curvature, due to stress relaxation. Methods: Ninety TLSs measuring 6 x 10 mm, produced out with 0.017 x 0.025-in TMA® wire and preactived by gradual curvature, were randomly distributed into nine groups according to time point of evaluation. Group 1 was tested immediately after spring preactivation and stress relief, by trial activation. The other eight groups were tested after 24, 48 and 72 hours, 1, 2, 4, 8 and 12 weeks, respectively. Using a moment transducer coupled to a digital extensometer indicator adapted to a universal testing machine, the amount of horizontal force, moment and moment-to-force ratios were recorded at every 0.5 mm of deactivation from 5 mm of the initial activation, in an interbracket distance of 23 mm. Results: The horizontal forces decreased gradually among the groups (p< 0.001) and the moments showed a significant and slow decrease over time among the groups (p< 0.001). All groups produced similar M/F ratios (p= 0.532), with no influence of time. Conclusions: The TLSs preactivated by curvature suffered a gradual deformation over time, which affected the force system, specifically the moments, which affected the horizontal forces produced.

scholarly journals Determination of the force systems produced by different configurations of tear drop orthodontic loops

2013 ◽  
Vol 18 (2) ◽  
pp. 19e1-19e18 ◽  
Author(s):  
Guilherme Thiesen ◽  
Roberto Hideo Shimizu ◽  
Caio Vinicius Martins do Valle ◽  
Karyna Martins do Valle-Corotti ◽  
Jefferson Ricardo Pereira ◽  
...  
Keyword(s):  
Mechanical Tests ◽  
Metal Alloy ◽  
Horizontal Force ◽  
Cross Sectional ◽  
Beta Titanium ◽  
Force Ratio ◽  
Cross Sectional Dimension ◽  
Force Systems ◽  
The Moment ◽  
Level Of Significance

OBJECTIVE: To determine the mechanical characteristics of teardrop loop with and without helix fabricated using different metal alloy compositions (stainless steel and beta-titanium), submitted to different intensities of bends preactivation (0º and 40º), and with different cross-sectional dimension of the wire used to build these loops (0.017 x 0.025-in and 0.019 x 0.025-in). METHODS: Eighty loops used to close spaces were submitted to mechanical tests. The magnitudes of horizontal force, the moment/force ratio, and the load/deflection ratio produced by the specimens were quantified. Loops were submitted to a total activation of 5.0 mm and the values were registered for each 1.0 mm of activation. For statistic data analysis, a analysis of variance was performed and a Tukey's Multiple Comparison test was used as supplement, considering a 5% level of significance. RESULTS: In general, teardrop loops with helix produced lower magnitudes of horizontal force and load/deflection ratio, and higher moment/force ratio than teardrop loops without helix. Among all analyzed variables, metal alloy composition presented greater influence in the horizontal force and in the load/deflection ratio. The moment/force ratio showed to be more influenced by the preactivation of loops for space closure.

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 Frictional forces between different Archwire-bracket Combinations

2014 ◽  
Vol 4 (1) ◽  
pp. 22-28 ◽  
Author(s):  
Vinit Singh ◽  
Swati Acharya ◽  
Satyabrata Patnaik ◽  
Smruti Bhusan Nanda
Keyword(s):  
Stainless Steel ◽  
Tooth Movement ◽  
Testing Machine ◽  
Frictional Resistance ◽  
Nickel Titanium ◽  
Orthodontic Bracket ◽  
Fixed Appliance ◽  
Beta Titanium ◽  
Frictional Forces

Introduction: During sliding mechanics, frictional resistance is an important counterforce to orthodontic tooth movement; whichmust be controlled to allow application of light continuous forces.Objective: To investigate static and kinetic frictional resistance between three orthodontic brackets: ceramic, self-ligating, andstainless steel, and three 0.019×0.025” archwires: stainless steel, nickel-titanium, titanium-molybdenum.Materials & Method: The in vitro study compared the effects of stainless steel, nickel-titanium, and beta-titanium archwires onfrictional forces of three orthodontic bracket systems: ceramic, self-ligating, and stainless steel brackets. All brackets had 0.022”slots, and the wires were 0.019×0.025”. Friction was evaluated in a simulated half-arch fixed appliance on a testing machine. Thestatic and kinetic friction data were analyzed with 1-way analysis of variance (ANOVA) and post-hoc Duncan multiple rangetest.Result: Self-ligating (Damon) brackets generated significantly lower static and kinetic frictional forces than stainless steel (Gemini)and ceramic brackets (Clarity). Among the archwire materials, Beta-titanium showed the maximum amount of frictional forceand stainless steel archwires had the lowest frictional force.Conclusion: The static and kinetic frictional force for stainless steel bracket was lowest in every combination of wire.

Beta-titanium biomedical alloy: effect of thermal processing on mechanical properties

2012 ◽  
Vol 57 (3) ◽  
pp. 753-757 ◽  
Author(s):  
K.V. Sudhakar ◽  
K. Konen ◽  
K. Floreen
Keyword(s):  
Mechanical Properties ◽  
Titanium Alloy ◽  
Testing Machine ◽  
Solution Treatment ◽  
High Strength ◽  
Fracture Morphology ◽  
Beta Titanium Alloy ◽  
Beta Titanium ◽  
Digital Microscope ◽  
Aging Conditions

A new β-titanium alloy (Ti-3Al-5V-6Cr-3Mo-3Zr) was investigated as a function of heat treatment to evaluate its mechanical properties. The cold drawn beta-titanium alloy was subjected to β-annealing as well as solution treatment and aging treatments. The mechanical properties were evaluated using MTS Landmark-servo hydraulic Universal Testing Machine. The beta-titanium alloy demonstrated an excellent combination of strength and ductility for both β-annealing and solution treatment and aging conditions. The influence of thermal treatments on microstructure was studied with HiRox digital microscope. The fracture morphology investigated revealed predominantly cup and cone/dimpled fracture surface features demonstrating excellent toughness in addition to high strength and low stiffness that are suitable for biomedical applications.

scholarly journals Ergonomic Fuzzy Evaluation of Firefighting Operation Motion

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Lifang Yang ◽  
Tianjiao Zhao ◽  
Fanyu Meng
Keyword(s):  
Evaluation System ◽  
Objective Evaluation ◽  
Comfort Level ◽  
Fuzzy Evaluation ◽  
Analytic Hierarchy ◽  
Engineering Software ◽  
Comprehensive Fuzzy Evaluation ◽  
Fuzzy Weight ◽  
The Moment ◽  
Hierarchy Process

The firefighting operation motion has an important impact on the safety and comfort of firefighting operation. As a judgment criterion of the firefighting efficiency, the comfort level is hard to judge in that it is completely decided by human feeling, so the comprehensive fuzzy evaluation is utilized for evaluation of comfort level. In this paper, firstly the factor and judgment set of firefighting operation comfort level are determined, and the fuzzy weight evaluation is obtained by questionnaires and analytic hierarchy process. Secondly, the joint angles of some particular motions are determined by motion capture equipment, the moment is obtained by ergonomic engineering software, and then the comprehensive comfort evaluation on firefighting operation motion is completed. Finally, the objective evaluation system of firefighting operation comfort is established.

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.

Evaluation on High Temperature Performance of Asphalt Mixture by Triaxial Dynamic Compression Test

2011 ◽  
Vol 97-98 ◽  
pp. 130-137
Author(s):  
Chuan Hai Wu
Keyword(s):  
High Temperature ◽  
Compression Test ◽  
Evaluation Method ◽  
Dynamic Compression ◽  
Testing Machine ◽  
Asphalt Mixture ◽  
Objective Evaluation ◽  
Road Pavement ◽  
Temperature Performance ◽  
Accumulated Strain

This paper aims to explore the reasonability of an evaluation method on high temperature performance of asphalt mixture through a series of experiements. The first step of these experiements is to formulate specimens of different high-temperature performances by Gyratory Testing Machine which simulates the on-road pavement to the most extent , and then adopt triaxial dynamic compression test to compare and analyze high-temperature performances of these specimens. By introducing concepts and indicators such as validity, reliability, discrimination, this paper evaluates comprehensively the discrimination results of various compression test parameters on high-temperature performance of asphalt mixture. It concludes that the evaluation effect of compression stiffness modulus is best, followed by the slope of logarithmic creep curve and accumulated strain area, and the evaluation effect of final compression strain is comparatively poor. That provides an objective evaluation method on high temperature performances of asphalt mixtures.

scholarly journals Experimental study of Young modulus of Attacus atlas, Vespa crabro, and Libellula depressa wings

2018 ◽  
Author(s):  
Michal Landowski ◽  
Zuzanna Kunicka-Kowalska ◽  
Krzysztof Sibilski
Keyword(s):  
Cross Section ◽  
Testing Machine ◽  
Young Modulus ◽  
Air Humidity ◽  
Bending Tests ◽  
Three Point Bending ◽  
Percentage Decrease ◽  
Vespa Crabro ◽  
The Moment ◽  
Do So

AbstractThis paper describes a scientific research aimed at obtaining data for determining Young modulus of the wings of selected insects’ species. A small testing machine intended for three-point bending and equipped with instruments registering low forces was constructed for the needs of the experiment. The machine was used to perform numerous bending tests of wings of three species of insects (obtained from a breeding farm): Attacus atlas, Vespa crabro, Libellula depressa in various air-humidity conditions. Values of the force and displacement obtained in the course of the tests were used to calculate Young modulus. In order to do so, it was also necessary to obtain the moment of inertia of the wing cross-section. These values were measured on the basis of the images obtained with a SEM microscope. Obtained results were averaged and presented with a breakdown by air-humidity conditions. It was observed that Young modulus decreased with an increase of humidity; hence the calculations of the percentage decrease of this mechanical parameter were performed. Obtained results were compared with the observed structure which was also presented under light microscope. It transpired that the construction of a wing does not only influence the mechanical values but also it influences their susceptibility to the changes occurring in the environment. Thereby, differences between Lepidoptera and Hymenoptera insects were indicated also within the aspect discussed in this paper.

Earthquake mechanism determination by S-wave data

1964 ◽  
Vol 54 (2) ◽  
pp. 457-474
Author(s):  
Anne E. Stevens
Keyword(s):  
Focal Mechanisms ◽  
Type I ◽  
Type Ii ◽  
S Wave ◽  
Force System ◽  
The Earth ◽  
The Family ◽  
Force Systems ◽  
Generalized Force ◽  
Earthquake Mechanism

ABSTRACT The nature of force systems at the foci of earthquakes can be studied by analyzing initial longitudinal (P) and transverse (S) displacements produced by them on the surface of the earth. The force system described in this paper results from a superposition of three mutually orthogonal double forces which act at a point focus. A family of equations is derived which depends only on S polarization angles and not on initial P displacements to determine the orientation of this generalized force system. An IBM 1620 computer has been programmed to solve the family of equations for two particular focal mechanisms—the single couple (Honda's Type I) and the double dipole (Honda's Type II). Two possible force systems are thus calculated for each earthquake using only S angles. The appropriate mechanism for each earthquake is selected by comparing the distribution of initial P displacements actually recorded, with that predicted from the solutions of the mechanism equations making use of S data. Computer solutions are presented for 32 earthquakes for which data are available in the literature. The orientation of the force system for each earthquake calculated from S data alone is in general agreement with that determined from P data.

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