scholarly journals Shape Optimization of Bone-Bonding Subperiosteal Devices with Finite Element Analysis

2017 ◽  
Vol 2017 ◽  
pp. 1-7
Author(s):  
Takeshi Ogasawara ◽  
Masayoshi Uezono ◽  
Kazuo Takakuda ◽  
Masanori Kikuchi ◽  
Shoichi Suzuki ◽  
...  
Keyword(s):  
Finite Element ◽  
Cross Section ◽  
Bonding Strength ◽  
Clinical Performance ◽  
Rectangular Cross Section ◽  
Optimum Shape ◽  
Bone Surface ◽  
Element Analysis ◽  
Cross Sectional ◽  
Rapid Acquisition

Subperiosteal bone-bonding devices have been proposed for less invasive treatments in orthodontics. The device is osseointegrated onto a bone surface without fixation screws and is expected to rapidly attain a bone-bonding strength that successfully meets clinical performance. Hence, the device’s optimum shape for rapid and strong bone bonding was examined in this study by finite element analyses. First, a stress analysis was performed for a circular rod device with an orthodontic force parallel to the bone surface, and the estimate of the bone-bonding strength based on the bone fracture criterion was verified with the results of an animal experiment. In total, four cross-sectional rod geometries were investigated: circular (Cr), elliptical (El), semicircular (Sc), and rectangular (Rc). By changing the height of the newly formed bone to mimic the progression of new bone formation, the estimation of the bone-bonding strength was repeated for each geometry. The rod with the Rc cross section exhibited the best performance, followed by those with the Sc, El, and Cr cross sections, from the aspects of the rapid acquisition of strength and the strength itself. Thus, the rectangular cross section is the best for rod-like subperiosteal devices for rapid bone bonding.

scholarly journals Influence of nickel-titanium rotary systems with varying cross-sectional, pitch, and rotational speed on deflection and cyclic fatigue: a finite element analysis study

2021 ◽  
Vol 41 ◽  
pp. 05005
Author(s):  
Wignyo Hadriyanto ◽  
Lukita Wardani ◽  
Christina Nugrohowati ◽  
Ananto Alhasyimi ◽  
Rachmat Sriwijaya ◽  
...  
Keyword(s):  
Finite Element ◽  
Cross Section ◽  
Rotational Speed ◽  
Cyclic Fatigue ◽  
Nickel Titanium ◽  
Element Analysis ◽  
Cross Sectional ◽  
Rotary Instruments ◽  
Section Design ◽  
Sectional Shape

The effectiveness of endodontic file preparation depends, among others, on the material, geometric shape, and the drive system. This study aimed to analyze the effect of cross-sectional, pitch, and rotational speed on cyclic fatigue and deflection of NiTi files using finite element analyses. A total of 18 NiTi endodontic rotary instruments ProTaper Gold F2 #25.08 and Hyflex CM #25.04 (n=9) modeling were designed using Autodesk software. Subjects were divided into two groups, the design group of square and convex triangles. Static simulation was then carried out to each group with force on the instrument’s tip by 1N, 2N, and 3N. The file’s cycling fatigue was analyzed at rotating speeds of 200 rpm, 300 rpm, and 400. The data were analyzed by using the three-way Analysis of variance (ANOVA) test followed by LSD (p< 0.05). The results showed the cross-sectional shape and force effect on the deflection value and cyclic fatigue received by the endodontic files (p< 0.05). The convex triangle design presented the lowest cyclic fatigue than square. The convex triangular cross-section design showed a higher deflection value than the square cross-section design.

Saint-Venant Decay Rates for the Rectangular Cross Section Rod

2004 ◽  
Vol 71 (3) ◽  
pp. 429-433 ◽  
Author(s):  
N. G. Stephen ◽  
P. J. Wang
Keyword(s):  
Finite Element ◽  
Aspect Ratio ◽  
Transfer Matrix ◽  
Cross Section ◽  
Cross Sections ◽  
Rectangular Cross Section ◽  
Decay Rates ◽  
Elastic Rod ◽  
Cross Sectional ◽  
Element Transfer

A finite element-transfer matrix procedure developed for determination of Saint-Venant decay rates of self-equilibrated loading at one end of a semi-infinite prismatic elastic rod of general cross section, which are the eigenvalues of a single repeating cell transfer matrix, is applied to the case of a rectangular cross section. First, a characteristic length of the rod is modelled within a finite element code; a superelement stiffness matrix relating force and displacement components at the master nodes at the ends of the length is then constructed, and its manipulation provides the transfer matrix, from which the eigenvalues and eigenvectors are determined. Over the range from plane stress to plane strain, which are the extremes of aspect ratio, there are always eigenmodes which decay slower than the generalized Papkovitch-Fadle modes, the latter being largely insensitive to aspect ratio. For compact cross sections, close to square, the slowest decay is for a mode having a distribution of axial displacement reminiscent of that associated with warping during torsion; for less compact cross sections, slowest decay is for a mode characterized by cross-sectional bending, caused by self-equilibrated twisting moment.

The Finite Element Analysis of Ultimate Bearing Capacity of Initial Bending on the T-Axis Compression Component

2013 ◽  
Vol 690-693 ◽  
pp. 1914-1918
Author(s):  
Yang Yang Han ◽  
Cai Xia Zhang ◽  
Ya Qin Li ◽  
Si Yu Chen ◽  
Chun Shan Liu
Keyword(s):  
Finite Element ◽  
Axial Compression ◽  
Cross Section ◽  
Element Calculation ◽  
Element Analysis ◽  
Cross Sectional ◽  
Buckling Behavior ◽  
The Finite Element Analysis ◽  
Axis Compression ◽  
The Stability

There is little research about the stability of T-stub steel axial compression component at home and abroad, and it remains to further investigation. On the basis of taking initial bending and other factors into consideration, through theoretical analysis and finite element calculation, this paper studies the T-stub steel axial compression buckling behavior and carrying capacity mainly using three different cross-section and different lengths ZC cross-sectional specimens.

scholarly journals Empirical Compliance Equations for Constant Rectangular Cross Section Flexure Hinges and Their Applications

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Tiemin Li ◽  
Yunsong Du ◽  
Yao Jiang ◽  
Jinglei Zhang
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
Cross Section ◽  
Rectangular Cross Section ◽  
Great Influence ◽  
Exponential Model ◽  
Geometrical Parameters ◽  
Element Analysis ◽  
Flexure Hinges ◽  
Wide Range

This paper presents the derivation of empirical compliance equations of the constant rectangular cross section flexure hinge. The stress concentration caused by changes in cross section is analyzed based on finite element analysis results for the purpose of overcoming compliance calculation errors. It shows that the stress concentration has great influence on axial compliance calculation, while it has little influence on shear and bending compliance calculation. Then empirical compliance equations with a relative wide range ofh/Landt/Lare derived based on the exponential model in conjunction with consideration of all geometrical parameters of flexure hinges and the influence of the stress concentration on axial compliance calculation. Finally, in order to verify the validity of the empirical equations, the input/output compliance and displacement amplification ratios of bridge-type microdisplacement amplification mechanisms are analyzed. Meanwhile, an experimental platform of displacement amplification mechanisms is set up. The experimental results and finite element method (FEM) values are in good agreement with the theoretical arithmetic, which demonstrates the accuracy of the empirical compliance equations. It provides a reference point for further studies on the design and optimization of flexure hinges and compliant mechanisms.

Finite Element Analysis and Structure Optimum of Rectangular Cylinder

2010 ◽  
Vol 44-47 ◽  
pp. 965-969
Author(s):  
Gui Bing Pang ◽  
Fei Teng ◽  
Chang Feng Yuan ◽  
Dian Min Li ◽  
Feng Yin Wang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Cross Section ◽  
Rectangular Cross Section ◽  
Wall Structure ◽  
Hydraulic Pressure ◽  
Cylinder Wall ◽  
Element Analysis ◽  
Rectangular Cylinder ◽  
Automobile Panel

In the press forming of some rectangular workpieces such as floor tiles and automobile panel, in order to make the hydraulic pressure distribute on the workpiece evenly and reduce the dimension of the cylinder, the rectangular cross-section piston has comparative advantages to the ordinary rounded cylinder. Finite Element Analysis (FEA) method is used to simulate the stress and deformation distribution of the rectangular cylinder. It is found that the largest deformation region is on the central of cylinder, the corner of the cylinder has the maximum stress. To decrease the deformation and stress, the convex cross-section shape and rounding corner is used, which effectively reduces the deformation and stress. By analyzing the influence of stress and strain under the conditions of different radius of the corner and different convexity of the cylinder wall, structure of the cylinder is optimized.

Natural Frequencies of Pre-Twisted Airfoil Blades

2017 ◽  
Author(s):  
Neeraj Kavan Chakshu ◽  
Sunil K. Sinha
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Free Boundary ◽  
Cross Section ◽  
Cross Sections ◽  
Natural Frequencies ◽  
Rectangular Cross Section ◽  
Element Analysis ◽  
Free Boundary Conditions ◽  
Airfoil Blades

In this paper, the natural frequencies of pre-twisted cantilever blades of various angles of twist having different airfoil cross sections in the NACA 6 series have been determined. The main objectives of this paper are to replicate the results previously published for the similar types of blades but with the assumption of a uniform rectangular cross-section and to compare it with the results obtained for blades with more refined airfoil cross-sections. Cantilevered type clamped-free boundary conditions have been used in this paper for all blades. The comparison of the natural frequencies among different airfoils of the same NACA series has also been described in the paper in order to find out if any parameter of the airfoil such as camber, maximum thickness etc have any significant role in changing the frequencies of the beam. Commonly used commercial codes for finite element analysis have been used to determine these results.

The tympanic membrane in cross section: a finite element analysis

1988 ◽  
Vol 102 (3) ◽  
pp. 209-214 ◽  
Author(s):  
T. H. J. Lesser ◽  
K. R. Williams
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Tympanic Membrane ◽  
Cross Section ◽  
Two Dimensional ◽  
Uniform Load ◽  
Pars Flaccida ◽  
Element Analysis ◽  
Cross Sectional ◽  
Number Of Factors

AbstractThis paper applies the technique of finite element analysis to the tympanic membrane. A Two-dimensional cross-sectional model of the tympanic membrane and malleus is described. A variety of experiments have been performed on this model, and displacements under a uniform load are analysed. The shape of the displaced membrane and the movement of the umbo were found tobe sensitive to a number of factors. These include the elastic modulus of the membrane, the presence and position of the axis or rotation of the malleus, and the size of the pars flaccida. Some implications of these results are discussed.

scholarly journals Engineering methods for calculation of elements from combined glued timber

2020 ◽  
Vol 11 (2) ◽  
pp. 79-90
Author(s):  
S. I. Bilyk ◽  
D. V. Mykhaіlovskyi
Keyword(s):  
Finite Element ◽  
Cross Section ◽  
Software Package ◽  
Strength Class ◽  
Rectangular Cross Section ◽  
Analytical Calculation ◽  
The Finite Element Method ◽  
Cross Sectional ◽  
Numerical Studies ◽  
Reduced Modulus

Extensive world experience in the implementation of building structures made of timber, in particular glued timber, for various purposes confirms the feasibility of their use. This is facilitated by the fact that glued timber effectively accumulates the positive properties of timber as a structural material level the shortcomings of solid timber. One of the types of constructions of glued timber are constructions of combined glued timber. Taking into account the structure and features of elements of combined glued timber of rectangular cross section, for a detailed analysis of the stress-strain state, a method is proposed, which consists in applying to standard formulas for calculating the reduced cross-sectional characteristics: reduced area, reduced moment of inertia, reduced moment of resistance. To calculation, the elements of combined glued timber of rectangular cross section according to the second limit state (serviceability), it is proposed to use the reduced modulus of elasticity of the section to the boards of the outer layers. To analyze the proposed method, a number of numerical studies of beams of combined and glued timber of the same strength class using analytical calculation methods and using the finite element method in the software package LIRA-CAD, using three-dimensional and flat finite elements. Numerical studies show that the results of calculations of beams of combined glued and glued timber of the same strength class differ within 20% in the direction of increasing the values of deflections and normal stresses in the elements of combined glued timber. Finite element calculations in the software package LIRA-CAD beams of combined and glued timber of the same strength class modeled volumetric and flat showed almost complete coincidence of results with a discrepancy of up to 2%, which suggests the need to significantly simplify the modeling, set elements from glued timber with flat finite elements. It is confirmed that the analytical calculation of beams of combined glued timber is recommended to be carried out according to the proposed method. The proposed technique allows to take into account the thickness and mechanical characteristics for the strength class of each board of which the glued cross section of the element, which significantly expands the range of use of combined glued timber. The high level of coincidence (within 5%) of the proposed analytical method with determination of the given cross-sectional characteristics with the results obtained by the finite element method for different cross-sections and spans of beams is confirmed, which allows to assert the expediency of its application in engineering calculations. In addition, the modeling of structures made of combined glued timber is possible with rod elements with the provision of the reduced modulus of elasticity according to the proposed method, which greatly simplifies the calculation of complex rod systems.

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