• Title/Summary/Keyword: transverse forces

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Equivalent Transverse Forces due to Longitudinal Prestressing of Box Girders (박스 거더의 종방향 프리스트레싱에 의한 횡방향 등가하중)

  • 양인환
    • Proceedings of the Korea Concrete Institute Conference
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    • 2003.05a
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    • pp.955-960
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    • 2003
  • For box girders in which the longitudinal tendon is profiled in the inclined webs. longitudinal prestressing force will induce transverse effects as well as longitudinal ones. In this paper. the method estimating transverse effects induced by longitudinal prestressing is proposed. The transverse effects in the slabs of box girders due to longitudinal prestressing are investigated. Numerical analyses are carried out depending on the parameters such as web inclination and ratio of girder length to tendon eccentricity. Analysis results show that when only prestressing are considered the magnitude of stresses in the slabs of box grder is not so large. However. if the other stresses due to dead and live load et al. are superposed on these stresses. it may be that the longitudinal prestressing effects are significant.

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Transverse flux circumferential induction method as a driving principle of the contact-free revolving stage (비접촉 회전 스테이지에의 구동 원리로서의 횡자속 원주형 유도 방법)

  • Kim, Hyo-Jun;Jung, Kwang-Suk
    • Journal of the Korean Society for Precision Engineering
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    • v.22 no.10 s.175
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    • pp.72-79
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    • 2005
  • Compared with linear induction principle, the transverse flux circumferential induction principle is suggested as a driving mechanism of the revolving stage, which can rotate contactlessly without any supporting structure. The stage realizes the integrated motion of levitation, rotation, and planar perturbation, using the two-axis forces, normally directed force of the air-gap and tangential force, of the induction drivers mounted on the stator uniformly. In this paper, the force generating mechanism of the stage is described in detail. First, the various core shapes generating the transverse flux are analyzed to guarantee the proper thrust force. And the vector force intensity of the circumferential induction driver constituting the stage is compared with that of the linear induction driver. Especially it is shown that the magnetic force of the suggested system can be modeled with the linear equivalent model, including the test verification.

Analysis of mechanical properties of microtubules under combined effects of surface and body forces for free and embedded microtubules in viscoelastic medium

  • Farid, Khurram;Taj, Muhammad
    • Advances in concrete construction
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    • v.13 no.3
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    • pp.255-264
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    • 2022
  • Vibration is expected to occur in microtubules as tubular heterodimers. They oscillate like electric dipoles. Several research studies have estimated a frequency of vibration using the orthotropic model, a beam or rod like models and shell models, considering the surface forces. The effects of body forces on the dynamics of the microtubules were not yet taken into account. This study seeks to capture the body force effects on the vibration modes generated and on the corresponding frequency for microtubules. An orthotropic elastic shell model for the structural details of microtubules is used for the analysis. The tests are conducted out for microtubules, exposed to electro-magnetic and gravitational forces, the transverse vibration, radial mode vibration, and axial mode of vibration have accomplished. We therefore, evaluate and compare microtubules' frequencies with prior results of vibration frequency without the effects of body force.

Design of Expansion Segment of Precast Prestressed Concrete Segmental Box Girder bridges Using Strut and Tie Model (스트럿 타이 모델을 이용한 프리캐스터 프리스트레스 콘크리트 세그멘탈 박스 거더 교량의 신축이음 세그멘트이 설계기법 연구)

  • 오병환;이형준;김익현;한승환
    • Proceedings of the Korea Concrete Institute Conference
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    • 1995.04a
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    • pp.268-273
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    • 1995
  • In recent years, precast prestressed concrete segmental box girder bridges have been increasingly constructed Expansion disphragm segment of this type bridge transfers forces from the superstructure onto bearing or column, and plays an important roll of anchorage zone for longitudinal prestressed forces. Non-linear stresses occur inside of diaphragms by these extensive concentrated forces. In this study, the strut-and-tie models are proposed to design an expansion segment rationally. A formula to determine the effective transverse prestressed forces is proposed on the basis of these models. The present study is expected to provide an effective tool to design expansion segment of prestressed concrete bridges rationally.

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Integrated Driver for the Full Rotation Using Six-axial Forces by the Induction Type of Axial-gap Motor (유도형 축방향 모터의 6축력 제어를 이용한 대회전 구현용 통합 구동기)

  • Jung Kwang-Suk;Lee Sang-Heon
    • Journal of Institute of Control, Robotics and Systems
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    • v.12 no.8
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    • pp.798-804
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    • 2006
  • To overcome the limited relative uncertainty and work range of the existing planar stage and the bulk structure of the contact-less motor for rotation, the novel operating principle to realize the precise rotation is suggested. It uses the two-axial vector forces, normal force and thrust force, of three-induction type of axial motors located $120^{\circ}$ apart, resulting in the contact-free rotation of the mover. Firstly in this paper, the magnetic forces across the air gap are modeled and simulated under the various conditions. It clarifies the feasible range of the derived solution. And the algorithm compensating the strong cross couple between the forces and the control inputs; generally AC magnitude and slip frequency, is given to realize the independent control of six axes. Finally, for the successfully implemented system, the round test and the micro step test results are given.

Retrofitting reinforced concrete beams by bolting steel plates to their sides -Part 2: Transverse interaction and rigid plastic design

  • Oehlers, Deric John;Ahmed, Marfique;Nguyen, Ninh T.;Bradford, Mark Andrew
    • Structural Engineering and Mechanics
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    • v.10 no.3
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    • pp.227-243
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    • 2000
  • In a companion paper, tests on bolted side plated beams have shown that side plates can substantially increase the strength of existing reinforced concrete beams with little if any loss of ductility and, furthermore, induce a gradual mode of failure after commencement of concrete crushing. However, it was also shown that transverse interaction between the side plates and the reinforced concrete beam, that is vertical slip and which is a concept unique to side plated beams, is detrimental. Transverse interaction increases the forces on the bolt shear connectors and, hence, weakens the beam. It also reduces the ability of the composite plated beam to yield and, hence, to attain its full flexural capacity. The generic concept of transverse interaction will be described in this paper and the results used to develop a new form of rigid plastic analysis for bolted side plated beams which is illustrated with an application.

Numerical Analysis of Prestressed Concrete Pavements Subjected to Transverse Post Tensioning (횡방향 긴장에 의한 프리스트레스트 콘크리트 포장의 거동분석)

  • Kim, Seong-Min;Yoon, Dong-Joo;Kim, Dong-Ho
    • International Journal of Highway Engineering
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    • v.10 no.4
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    • pp.257-267
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    • 2008
  • This study was conducted to investigate the stress distribution in the prestressed concrete pavement (PSCP) when the transverse post tensioning was applied. By performing the structural analyses using a finite element model of PSCP, the effect of anchor spacing and the relationship between the longitudinal and transverse post tensioning were evaluated. The analysis results showed that as the anchor spacing became smaller, the stresses were more uniformly distributed and the ranges of the stress losses were reduced; however, the economy should be considered. As the anchor spacing became larger, the difference between the average transverse stress and the transverse stresses at various locations such as shoulder, wheel pass, and center of the slab, increased. The transverse post tensioning induced the additional tensile forces in the longitudinal tendons, but the magnitude was negligibly small, and the longitudinal and transverse post tensioning could be designed independently. The use of the transverse stress distribution for the design of the post tensioning was also discussed in this paper.

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A Fundamental Study on the Transverse Stability of Ships in Following Seas (추파중에서 항행하는 선박의 복원성능에 관한 기초적 연구)

  • 윤진동;손경호
    • Journal of the Korean Institute of Navigation
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    • v.11 no.2
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    • pp.61-72
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    • 1987
  • When a ship is running in following seas, the encounter frequency is reduced to a very low one. In that case broaching, surfiding and capsizing phenomena are most likely to occur due to wave exciting forces acting on a ship in following seas. In this paper, the emphasis is mainly laid upon transverse stability of ships following seas, which is related to capszing phenomenon. The authors take the case that ship speed is equal to the wave celerity, i.e., the encounter frequency is zero. Hydrostatic force and moment due to Froude-Krylov hypothesis are calculated by line intergral method. Transverse stability is evaluated from hydrostatic force and moment. Through the application of present calculation method to box-shaped vessel, it is confirmed that the transversestability of a vessel can be reduced to critical level at wave crest.

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Analysis of the Magnetic Force and Torque of a Rotatory Two-Phase Transverse Flux Machine (회전형 이상 횡자속형 전동기에서 발생하는 자기력 및 토크 해석)

  • Park, Nam-Ki;Chang, Jung-Hwan;Jang, Gun-Hee
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2006.11a
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    • pp.829-835
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    • 2006
  • Rotatory two-phase transverse flux machine(TFM) is a relatively new type of motor with high power density, high torque, and low speed in comparison to conventional electrical motors. However, it has some shortcomings,.i.e. complex construction and high possibility of the magnetically induced vibration due to its inherent structure. This paper investigates the characteristics of the magnetic force and the torque in the rotatory two-phase TFM by using the 3-D finite element method and the spectral analysis. This research shows that the average torque decreases and that the torque ripple increases as the phase delay increases. It also shows that the unbalanced magnetic force is one of the dominant excitation forces in this machine. And it proposes a new topology of rotatory two-phase TFM to eliminate the unbalanced magnetic force.

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Characteristic Analysis of a Permanent Magnet Transverse Flux Linear Motor with Spiral Core

  • Lee, Ji-Young;Kim, Ji-Won;Woo, Byung-Chul;Kang, Do-Hyun
    • Journal of Magnetics
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    • v.18 no.2
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    • pp.111-116
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    • 2013
  • This paper presents a characteristic analysis method of a permanent magnet type transverse flux linear motor (TFLM) with spiral cores. The spiral cores are used as the mover cores in order to make 3-dimensional (3-D) magnetic flux paths at the TFLM which have 3-D magnetic flux flows. The 3-D Equivalent Magnetic Circuit Network Method is used to analyse the magnetic characteristics of the machine, and an imaginary part, 'flux barrier,' is introduced to consider the spiral core characteristic. Magnetic parameters such as flux, inductance, and thrust are calculated from the analysis results. The computed thrust forces are compared to measured values to confirm the accuracy of the analysis.