• Title/Summary/Keyword: axial path

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Enumeration of axial rotation

  • Yoon, Yong-San
    • Advances in biomechanics and applications
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    • v.1 no.2
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    • pp.85-93
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    • 2014
  • In this paper, two procedures of enumerating the axial rotation are proposed using the unit sphere of the spherical rotation coordinate system specifying 3D rotation. If the trajectory of the movement is known, the integration of the axial component of the angular velocity plus the geometric effect equal to the enclosed area subtended by the geodesic path on the surface of the unit sphere. If the postures of the initial and final positions are known, the axial rotation is determined by the angular difference from the parallel transport along the geodesic path. The path dependency of the axial rotation of the three dimensional rigid body motion is due to the geometric effect corresponding to the closed loop discontinuity. Firstly, the closed loop discontinuity is examined for the infinitesimal region. The general closed loop discontinuity can be evaluated by the summation of those discontinuities of the infinitesimal regions forming the whole loop. This general loop discontinuity is equal to the surface area enclosed by the closed loop on the surface of the unit sphere. Using this quantification of the closed loop discontinuity of the axial rotation, the geometric effect is determined in enumerating the axial rotation. As an example, the axial rotation of the arm by the Codman's movement is evaluated, which other methods of enumerating the axial rotations failed.

Evaluation of Axial Strains of Reinforced Concrete Columns (철근콘크리트 기둥의 축방향 변형률 평가)

  • Lee, Jung-Yoon;Kim, Min-Ok;Kim, Hyung-Beom
    • Journal of the Korea Concrete Institute
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    • v.25 no.1
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    • pp.19-28
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    • 2013
  • The longitudinal axial strain in the plastic hinge region of reinforced concrete (RC) columns influences on the structural behavior of RC structures subjected to reversed cyclic loading. This strain decreases the effective compressive strength of concrete and increases the lateral displacements between stories by causing the elongation of member length. This paper investigated the effects of the axial force on the elongation of a RC member by using a sectional analysis of RC members. The analytical and experimental results indicated that the axial force decreased the axial strain in the plastic hinge region of RC columns. In this study, a model was proposed to predict the axial strain of RC columns. The proposed model considering the effects of axial force ratio consisted of three path types ; Path 1-loading region, Path 2-unloading region, and Path 3-reversing cyclic loading region. The axal strains predicted by the proposed model were compared with the test results of RC columns with various axial force ratios, and agreed reasonably with the observed longitudinal strains.

Loading Path Optimization in Aluminum Tube Hydroforming using Response Surface Method (반응표면법을 이용한 알루미늄 튜브 하이드로포밍의 하중경로 최적화)

  • Lim, H.T.;Kim, H.J.;Kim, H.Y.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2007.05a
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    • pp.314-317
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    • 2007
  • Automotive rear subframe of aluminum tube was developed by using hydroforming process, based on the numerical analysis and physical tryouts. In the previous study, the effect of prebending was evaluated on the basis of forming limit diagram which had been obtained from free bulging, T-shape forming and cross-shape forming, using the developed tube hydroformability testing system. In order to get the sound products, appropriate internal pressure is to be imposed corresponding to the axial feeding. In this study, the loading path, the combination of internal pressure and axial feeding during the process, was optimized to ensure minimum thickness variation and dimensional accuracy, by using response surface method.

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Cap truss and steel strut to resist progressive collapse in RC frame structures

  • Zahrai, Seyed Mehdi;Ezoddin, Alireza
    • Steel and Composite Structures
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    • v.26 no.5
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    • pp.635-647
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    • 2018
  • In order to improve the efficiency of the Reinforced Concrete, RC, structures against progressive collapse, this paper proposes a procedure using alternate path and specific local resistance method to resist progressive collapse in intermediate RC frame structures. Cap truss consists of multiple trusses above a suddenly removed structural element to restrain excessive collapse and provide an alternate path. Steel strut is used as a brace to resist compressive axial forces. It is similar to knee braces in the geometry, responsible for enhancing ductility and preventing shear force localization around the column. In this paper, column removals in the critical position at the first story of two 5 and 10-story regular buildings strengthened using steel strut or cap truss are studied. Based on nonlinear dynamic analysis results, steel strut can only decrease vertical displacement due to sudden removal of the column at the first story about 23%. Cap truss can reduce the average vertical displacement and column axial force transferred to adjacent columns for the studied buildings about 56% and 61%, respectively due to sudden removal of the column. In other words, using cap truss, the axial force in the removed column transfers through an alternate path to adjacent columns to prevent local or general failure or to delay the progressive collapse occurrence.

Axial Strain Of Reinforced Concrete Beams Subjected to Reversed Cyclic Loading (반복하중을 받는 철근콘크리트 보의 부재 축방향 변형률에 관한 연구)

  • 이정윤
    • Journal of the Korea Concrete Institute
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    • v.13 no.3
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    • pp.251-260
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    • 2001
  • It is required to evaluate the axial strain of reinforced concrete beams in order to predict the ductility of reinforced concrete beams subjected to reversed cyclic loading. A model was proposed to determine the axial strains In reinforced concrete beams by analysing the behavior of reinforced concrete sections and comparing with published test results. The proposed axial strain model inclusively reflected four kinds of paths : Path 1-steel bar in an elastic stage or a unloading region; Path 2-after flexural yielding; Path 3-a slip region; and Path 4-a reversing loading region. The equations to predict the axial strains of each path were proposed. The proposed equations took into account the effects of the loading program. Comparison of axial strains between experimental results and the results from proposed equations showed to be in a good agreement with experimental results.

Design and Characteristic Analysis of Double Stator Axial Field 12/10 SRM (이중고정자 횡축 12/10 SRM의 설계 및 특성 해석)

  • Son, Dong-Ho;Ahn, Jin-Woo
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.67 no.6
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    • pp.730-737
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    • 2018
  • This paper aims to design of a double stator axial field 12/10 SRM. Conventional and single stator axial field SRMs were reviewed to apply for automotive cooling fan. The axial field SRM has the advantage of shorter flux path, higher torque per volume and lower iron loss. However, there is axial eccentricity in single stator axial field SRM due to one side excitation. Therefore, a double stator type is designed in this paper to reduce the axial eccentricity. And the trapezoidal pole shape of the stator increases the flow of magnetic flux from stator to rotor and the torque region. The torque and efficiency are compared and tested with experiments.

Influence of fiber paths on buckling load of tailored conical shells

  • Naderi, Ali-Asghar;Rahimi, Gholam-Hossein;Arefi, Mohammad
    • Steel and Composite Structures
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    • v.16 no.4
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    • pp.375-387
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    • 2014
  • The purpose of this paper is to propose a method for evaluation of varying stiffness coefficients of tailored conical shells (TCS). Furthermore, a comparison between buckling loads of these shells under axial load with the different fiber path is performed. A circular truncated conical shell subjected to axial compression is taken into account. Three different theoretical path containing geodesic path, constant curvature path and constant angle path has been considered to describe the angle variation along the cone length, along cone generator of a conical shell are offered. In the TCS with the arbitrary fiber path, the thickness and the ply orientation are assumed to be functions of the shell coordinates and influencing stiffness coefficients of the structure. The stiffness coefficients and the buckling loads of shells are calculated basing on classical shells theory (CST) and using finite-element analysis (FEA) software. The obtained results for TCS with arbitrary fiber path, thickness and ply orientation are derived as functions of shell longitudinal coordinate and influencing stiffness coefficients of structures. Furthermore, the buckling loads based on fiber path and ply orientation at the start of tailored fiber get to be different. The extent of difference for tailored fiber with start angle lower than 20 degrees is not significant. The results in this paper show that using tailored fiber placement could be applied for producing conical shells in order to have greater buckling strengths and lower weight. This work demonstrates the use of fiber path definitions for calculated stiffness coefficients and buckling loads of conical shells.

A Study on Structural Improvement of the Swashplate Axial Piston Pump Valve Block (2) (사판 식 축 피스톤 펌프 밸브블록의 구조개선에 관한 연구(2))

  • Kim, Jeong-Hwa;Shin, Mi-Jung;Kim, Myung-Kyu
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.17 no.1
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    • pp.76-81
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    • 2018
  • This study aims to provide ways to achieve structural improvements of the internal flow path of the discharge plenum of a swash plate piston pump valve block vulnerable to cracks. This paper corresponds to Part II, which consists of a structural interpretation of the internal flow path of the discharge plenum of the valve block. The simple model result reviewed in Part I was incorporated into the valve block model and five different design changes were reviewed as part of the study on the structural improvement of the internal flow path of the valve block.

Axial map Implementation Using Linear Generalization of GIS data (GIS 도로 데이터의 일반화를 이용한 Axial map 구현 방법에 관한 연구)

  • Kwon, Soon-Il;Park, Soo-Hong;Joo, Yong-Jin
    • Spatial Information Research
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    • v.18 no.4
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    • pp.99-108
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    • 2010
  • Space Syntax methodology can be quantitatively calculated spatial cognitive analysis by number of turns_ In the existing GIS-based spatial information service provide 'physical distance' due to the shortest distance as a priority. but pedestrians tends to choose the path with concerned a lot of emphasis of safety, more vitality way from the crime at night, traffic accidents, and comfort on a road. Human's 'psychological distance' may reflect the spatial information services and provided path should be. In this study, using GIS Road Data implements the axial map with idea of the linear simplification principles. Traditional axial map of the Space Syntax get the assumption from the actual traffic values by comparing the results of correlation relationship. Through these methods, the actual relationship between traffic and test values have the correlation value($R^2$= 0.5387) 50% level and was able to get the results.

Effect of axial load on flexural behaviour of cyclically loaded RC columns

  • Au, F.T.K.;Bai, Z.Z.
    • Computers and Concrete
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    • v.3 no.4
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    • pp.261-284
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    • 2006
  • The flexural behaviour of symmetrically reinforced concrete (RC) columns cast of normal- and high-strength concrete under both monotonic and cyclic loading is studied based on an analytical procedure, which employs the actual stress-strain curves and takes into account the stress-path dependence of concrete and steel reinforcement. The analysis is particularly extended into the post-peak stage with large inelastic deformation at various applied axial load level. The effect of axial load on their complete flexural behaviour is then identified based on the results obtained. The axial load is found to have fairly large effect on the flexural behaviour of RC columns under both monotonic and cyclic loading. Such effects are discussed through examination of various aspects including the moment-curvature relationship, moment capacity, flexural ductility, variation of neutral axis depth and steel stress.