• Title/Summary/Keyword: side to thickness ratio

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The Effect of the diameter and anastomotic angles on the compliance and the stress distribution of the end-to-side anastomosis (직경 및 문합각도가 단측 문합의 컴플라이언스 및 응력분포에 미치는 영향)

  • Han, G.J.;Kim, Y.H.;Kim, H.S.;Ann, S.C.;Jang, W.S.
    • Proceedings of the KOSOMBE Conference
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    • v.1997 no.05
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    • pp.334-337
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    • 1997
  • Von Mises stress and compliance distribution was evaluated using a finite element analysis on the end-to-side anastomosis of an artery with length of $20\sim24mm$, inner diameter of 4mm, thickness of 0.5mm and a PTFE graft with length of 10mm, inner diameter of 2mm, thickness of 0.2mm when the anastomotic angle was taken from $30^{\circ}\sim90^{\circ}$ in every $10^{\circ}$ and the diameter ratio from $0.1\sim1$ in every 0.1. The inner pressure of $1330dyne/mm^2$ was applied inside the 2 conduits. It was found that the compliance whose magnitude is larger on the acute angle anastomotic side than on the acute angle side became larger as the anastomotic angle became smaller and the diameter ratio larger and that the equivalent stress on the acute angle anastomotic side was larger than that on the abtuse angle side and became larger as the anastomotic angle and the diameter ratio became larger.

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The Effect of the Diameter and Anastomotic Angle on the Compliance and the Stress Distribution of the End-to-side Anastomosis. (직경 및 문합각도가 단측 문합의 컴플라이언스 및 응력분포에 미치는 영향)

  • 한근조;김영호
    • Journal of Biomedical Engineering Research
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    • v.19 no.2
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    • pp.183-188
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    • 1998
  • Von Mises stress and compliance distribution was evaluated using a finite element analysis on the end-to-side anastomosis of an artery with length of 20-24mm, inner diameter of 4mm, thickness of 0.5mm and a PTFE graft with length of 10mm, inner diameter of 2mm, thickness of 0.2mm when the anastomotic angle was taken from 30$^{\circ}$~90$^{\circ}$ in every 10$^{\circ}$ and the diameter ratio from 0.1-1 in every 0.1. The inner pressure of 1330 dyne/$\textrm{mm}^2$ was applied inside the 2 conduits. It was found that the compliance whose magnitude is larger on the acute angle anastomotic side than on the abtuse angle side became larger as the anastomotic angle became smaller and the diameter ratio larger and that the equivalent stress on the acute angle anastomotic side was larger than that on the abtuse angle side and became larger as the anastomotic angle and the diameter ratio became larger.

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Relationship of the Shape of Subacromial Spur and Rotator Cuff Partial Thickness Tear

  • Kim, Young-Kyu;Jung, Kyu-Hak;Kang, Suk-Woong;Hong, Jin-Hun;Choi, Ki-Yong;Choi, Ji-Uk
    • Clinics in Shoulder and Elbow
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    • v.22 no.3
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    • pp.139-145
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    • 2019
  • Background: The present study was undertaken to evaluate the relationship between location of the rotator cuff tear and shape of the subacromial spur. Methods: Totally, 80 consecutive patients who underwent arthroscopic repair for partial thickness rotator cuff tear were enrolled for the study. Bigliani's type of the acromion, type of subacromial spur, and location of partial thickness tear of the rotator cuff were evaluated using plain X-ray and magnetic resonance imaging. We then compared the groups of no spur with spur, and heel with traction spur. Results: Of the 80 cases, 25 cases comprised the no spur group, and 55 cases comprised the spur group. There was a significant difference in type of tear (p=0.0004) between these two groups. Bursal side tears were significantly greater (odds ratio=6.000, p=0.0007) in the spur group. Subjects belonging to the spur group were further divided into heel (38 cases) and traction spur (17 cases). Comparing these two groups revealed significant differences only in the type of tear (p=0.0001). Furthermore, the heel spur had significantly greater bursal side tear (odds ratio=29.521, p=0.0005) as compared to traction spur. Conclusions: The heel spur is more associated to bursal side tear than the traction spur, whereas the traction spur associates greater to the articular side tear.

A Study on the Influence Factors on Flexural and Thickness Modes in the Impact-echo Test (충격반향기법에서의 휨 모드 및 두께 모드의 영향인자에 대한 연구)

  • Oh, Tae-Keun;Park, Jongl-Il;Byun, Yoseph;Lee, Young-Hak
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.28 no.6
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    • pp.659-666
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    • 2015
  • In this paper, various influence factors on the impact-echo test which is an effective method in characterizing defects such as such as the delamination in the concrete structures were studied. The side to thickness ratio(a/h), the relative position of impacting and sensing points over the delamination that have great effects on the flexural and impact-echo(thickness) modes were investigated and examined by the parametric finite element analysis. As a result, the flexural modes dominate in the case of a/h > 2 and the thickness mode was more evident when a/h < 2. With regard to the relative position of impact source and sensing point to the defect, the flexural modes dominate even when either the loading or sensing point was over the delamination defect. However, the thickness mode prevails when both the impacting and sensing points are over the solid region beyond the delamination area.

Non-linear thermal buckling of FG plates with porosity based on hyperbolic shear deformation theory

  • Hadji, Lazreg;Amoozgar, Mohammadreza;Tounsi, Abdelouahed
    • Steel and Composite Structures
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    • v.42 no.5
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    • pp.711-722
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    • 2022
  • In this paper, hyperbolic shear deformation plate theory is developed for thermal buckling of functionally graded plates with porosity by dividing transverse displacement into bending and shear parts. The present theory is variationally consistent, and accounts for a quadratic variation of the transverse shearstrains across the thickness and satisfies the zero traction boundary conditions on the top and bottom surfaces of the plate without using shear correction factors. Three different patterns of porosity distributions (including even and uneven distribution patterns, and the logarithmic-uneven pattern) are considered. The logarithmic-uneven porosities for first time is mentioned. Equilibrium and stability equations are derived based on the present theory. The non-linear governing equations are solved for plates subjected to simply supported boundary conditions. The thermal loads are assumed to be uniform, linear and non-linear distribution through-the-thickness. A comprehensive parametric study is carried out to assess the effects of volume fraction index, porosity fraction index, aspect ratio and side-to-thickness ratio on the buckling temperature difference of imperfect FG plates.

Buckling analysis of arbitrary two-directional functionally graded nano-plate based on nonlocal elasticity theory using generalized differential quadrature method

  • Emadi, Maryam;Nejad, Mohammad Zamani;Ziaee, Sima;Hadi, Amin
    • Steel and Composite Structures
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    • v.39 no.5
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    • pp.565-581
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    • 2021
  • In this paper the buckling analysis of the nanoplate made of arbitrary bi-directional functionally graded (BDFG) materials with small scale effects are investigated. To study the small-scale effects on buckling load, the Eringen's nonlocal theory is applied. Employing the principle of minimum potential energy, the governing equations are obtained. Generalize differential quadrature method (GDQM) is used to solve the governing equations for various boundary conditions to obtain the buckling load of BDFG nanoplates. These models can degenerate into the classical models if the material length scale parameter is taken to be zero. Comparison between the results of GDQ method and other papers for buckling analysis of a simply supported rectangular nano FGM plate reveals the accuracy of GDQ method. At the end some numerical results are presented to study the effects of material length scale parameter, plate thickness, aspect ratio, Poisson's ratio boundary condition and side to thickness ratio on size dependent Frequency.

Height-thickness ratio on axial behavior of composite wall with truss connector

  • Qin, Ying;Shu, Gan-Ping;Zhou, Xiong-Liang;Han, Jian-Hong;He, Yun-Fei
    • Steel and Composite Structures
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    • v.30 no.4
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    • pp.315-325
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    • 2019
  • Double skin composite walls offer structural and economic merits over conventional reinforced concrete counterparts in terms of higher capacity, greater stiffness, and better ductility. This paper investigated the axial behavior of double skin composite walls with steel truss connectors. Full-scaled tests were conducted on three specimens with different height-to-thickness ratios. Test results were evaluated in terms of failure mode, load-axial displacement response, buckling loading, axial stiffness, ductility, strength index, load-lateral deflection, and strain distribution. The test data were compared with AISC 360 and Eurocode 4 and it was found that both codes provided conservative predictions on the safe side.

Microstructure and Mechanical Property in Thickness Direction of a Deoxidized Low-Phosphorous Copper Sheet Processed by Two-Pass Differential Speed Rolling (2-pass 이주속압연된 인탈산동판재의 두께방향으로의 미세조직 및 기계적 특성)

  • Lee, Seong-Hee;Jang, Jun-Hyuk;Utsunomiya, Hiroshi
    • Korean Journal of Materials Research
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    • v.23 no.7
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    • pp.392-398
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    • 2013
  • A two-pass differential speed rolling(DSR) was applied to a deoxidized low-phosphorous copper alloy sheet in order to form a homogeneous microstructure. Copper alloy with a thickness of 3 mm was rolled to 75 % reduction by two-pass rolling at $150^{\circ}C$ without lubrication at a differential speed ratio of 2.0:1. In order to introduce uniform shear strain into the copper alloy sheet, the second rolling was performed after turning the sample by $180^{\circ}$ on the transverse direction axis. Conventional rolling(CR), in which the rotating speeds of the upper roll and lower roll are identical to each other, was also performed by two-pass rolling under a total rolling reduction of 75 %, for comparison. The shear strain introduced by the conventional rolling showed positive values at positions of the upper roll side and negative values at positions of the lower roll side. However, samples processed by the DSR showed zero or positive values at all positions. {100}//ND texture was primarily developed near the surface and center of thickness for the CR, while {110}//ND texture was primarily developed for the DSR. The difference in misorientation distribution of grain boundary between the upper roll side surface and center regions was very small in the CR, while it was large in the DSR. The grain size was smallest in the upper roll side region for both the CR and the DSR. The hardness showed homogeneous distribution in the thickness direction in both CR and DSR. The average hardness was larger in CR than in DSR.

Forming Characteristics of Laser Welded Tailored Blanks (레이저 용접 테일러드 블랭크의 성형특성)

  • 박기철;한수식;김광선;권오준
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1998.06a
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    • pp.121-130
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    • 1998
  • In order to analyze the forming characteristics of laser welded tailored blanks, laser welded blanks of different thickness and strength combinations were prepared and tensile, stretching, stretch flanging and deep drawing tests were done. The tensile elongation perpendicular to the weld line, stretching and stretch flanging formability decreased with increasing the deformation restraining force (strength ${\times}$ thickness) ratio between two welded sheets. The tensile elongation along weld line reached a value above 90% of the single sheet's elongation. Stretch flanging formability was reduced to approximately 10% of the single sheet value when the deformation restraining force ratio between two welded sheets was increased to two. Weld line movement of deep drawing test specimens was also affected by the strength ratio of the combined sheets, the weld line location and forming conditions. In all forming modes of tailored blanks, excessive weld line movement resulted from strain concentrations at the weaker sheet and resulted in fracture of the weaker side.

Influence of Harmonic Modulator Shape on the Cogging Force of Magnetic Gear (고조파 조절기 형상이 자석 기어의 코깅 자기력에 미치는 영향 분석)

  • Kwangsuk, Jung
    • Journal of Institute of Convergence Technology
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    • v.12 no.1
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    • pp.7-12
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    • 2022
  • The reduction ratio of the magnetic gear is determined by the ratio of the number of poles between the high-speed permanent magnet layer and the low-speed permanent magnet layer. In general, it is known that the greater the least common multiple of both poles, the smaller the torque ripple called by cogging of the magnetic force generated in the magnetic gear. However, little is known about the effect of the harmonic modulator that filters the magnetic field in the magnetic gear to magnetically couple the high-speed side and the low-speed side except for the number of poles. In this study, torque ripple characteristics according to changes in modulator shape such as opening ratio and tooth thickness are analyzed using a finite element analysis tool.