• 제목/요약/키워드: Lateral Force

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팔꿉관절 가쪽 부위에 적용한 다이아몬드 테이핑이 정상인의 공동폄근 힘줄의 두께와 악력, 손목 폄력에 미치는 영향 (Effects of Diamond Taping Applied Around the Lateral Elbow on Common Extensor Tendon Thickness, Grip Strength and Wrist Extension Force in Healthy Subjects)

  • 박소현;김선엽
    • 한국전문물리치료학회지
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    • 제27권3호
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    • pp.163-170
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    • 2020
  • Background: The characteristics of lateral epicondylitis (LE) are muscle strength weakness and increased common extensor tendon (CET) thickness. Ultrasonography has recently been used to evaluate tendinopathy. Diamond taping (DT) is commonly used to manage patients with LE. However, no previous studies have investigated the effects of DT on CET thickness. Objects: The aim of this study was to investigate the effects of DT applied around the lateral elbow on CET thickness, grip strength, and wrist extension force in healthy subjects. Methods: The subjects were 26 adults (13 male) in their twenties. First, the CET thickness was measured at rest. The CET thickness was measured by using ultrasonography at two points. The subjects were then instructed to perform maximal grip activities or maximal wrist extension activities before and after DT around the lateral elbow. The DT technique was applied using non-elastic tape. While the subjects performed maximal grip activities, the investigator measured the maximum grip strength (MGS) and CET thickness. Likewise, while the subjects performed maximal wrist extension activities, the investigator measured the maximum wrist extension force (MWEF) and CET thickness. Results: The MGS showed a statistically significant improvement after DT taping application in men (p < 0.05). The MWEF showed a statistically significant improvement after DT application in male (p < 0.01) and female (p < 0.05). When performing the activities, the CET thickness increased compared to that at rest. However, CET thickness didn't show a statistically significant improvement before and after DT. Conclusion: This study shows that DT applied around the lateral elbow is effective in improving MGS and MWEF. However, it does not affect CET thickness.

KBC2008(안)에 근거한 무량판구조의 횡력저항시스템 (Lateral Force Resisting System of Flat Plate Structure based on KBC 2008 Draft)

  • 김도현;이현호;김영식;우성우
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2008년도 추계 학술발표회 제20권2호
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    • pp.871-874
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    • 2008
  • KBC 2005를 처음 적용할 때 많은 구조엔지니어들이 무량판 구조에 대한 횡력저항시스템 선정과이에 따른 상세적용에 많은 어려움이 있었다. 현재 KBC 2005에 대한 개정작업이 진행중에 있다. 이러한 시점에서 최근 개정 중인 건축구조기준의 개정안을 토대로 향후 개정안에 적용가능한 구조시스템을 미리 살펴볼 필요가 있다. KBC 2008(안)의 경우 내진설계범주에 따른 시스템의 높이제한, 특수전단벽과 같은 특수상세, 전단벽-골조 상호작용시스템과 같은 새로운 시스템의 도입으로 구조설계자가 현행 기준보다 시스템에 대하여 휠씬 더 다양한 선택이 가능할 것으로 판단된다.

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Vertical distributions of lateral forces on base isolated structures considering higher mode effects

  • Tsai, C.S.;Chen, Wen-Shin;Chen, Bo-Jen;Pong, Wen-Shen
    • Structural Engineering and Mechanics
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    • 제23권5호
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    • pp.543-562
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    • 2006
  • Base isolation technology has been accepted as a feasible and attractive way in improving seismic resistance of structures. The seismic design of new seismically isolated structures is mainly governed by the Uniform Building Code (UBC-97) published by the International Conference of Building Officials. In the UBC code, the distribution formula of the inertial (or lateral) forces leads to an inverted triangular shape in the vertical direction. It has been found to be too conservative for most isolated structures through experimental, computational and real earthquake examinations. In this paper, four simple and reasonable design formulae, based on the first mode of the base-isolated structures, for the lateral force distribution on isolated structures have been validated by a multiple-bay three-story base-isolated steel structure tested on the shaking table. Moreover, to obtain more accurate results for base-isolated structures in which higher mode contributions are more likely expected during earthquakes, another four inertial force distribution formulae are also proposed to include higher mode effects. Besides the experimental verification through shaking table tests, the vertical distributions of peak accelerations computed by the proposed design formulae are in good agreement with the recorded floor accelerations of the USC University Hospital during the Northridge earthquake.

Super convergent laminated composite beam element for lateral stability analysis

  • Kim, Nam-Il;Choi, Dong-Ho
    • Steel and Composite Structures
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    • 제15권2호
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    • pp.175-202
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    • 2013
  • The super convergent laminated composite beam element is newly derived for the lateral stability analysis. For this, a theoretical model of the laminated composite beams is developed based on the first-order shear deformation beam theory. The present laminated beam takes into account the transverse shear and the restrained warping induced shear deformation. The second-order coupling torque resulting from the geometric nonlinearity is rigorously derived. From the principle of minimum total potential energy, the stability equations and force-displacement relationships are derived and the explicit expressions for the displacement parameters are presented by applying the power series expansions of displacement components to simultaneous ordinary differential equations. Finally, the member stiffness matrix is determined using the force-displacement relationships. In order to show accuracy and superiority of the beam element developed by this study, the critical lateral buckling moments for bisymmetric and monosymmetric I-beams are presented and compared with other results available in the literature, the isoparametric beam elements, and shell elements from ABAQUS.

Lateral loading test for partially confined and unconfined masonry panels

  • Tu, Yi-Hsuan;Lo, Ting-Yi;Chuang, Tsung-Hua
    • Earthquakes and Structures
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    • 제18권3호
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    • pp.379-390
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    • 2020
  • Four full-scaled partially confined and unconfined masonry panels were tested with monotonic lateral loads. To study the effects of vertical force and boundary columns, two specimens with no boundary columns were subjected to different vertical forces, while two wing-wall specimens had the column placed eccentrically and in the middle, respectively. The specimens with no boundary columns exhibited ductile rocking behavior, where the lateral strength increased with increasing vertical compression. The wing-wall specimens with columns behaved as strut-and-tie systems. The column-panel interaction resulted in greater strength, lower deformation capacity and differences in failure modes. A comparison with analytical models showed that rocking strength can be accurately estimated using vertical force and the panel aspect ratio for panels with no boundary columns. The estimation for lateral strength on the basis of a panel section area indicated scattered error for wing-wall specimens.

Shear behavior of exposed column base connections

  • Cui, Yao
    • Steel and Composite Structures
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    • 제21권2호
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    • pp.357-371
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    • 2016
  • Column base connections are critical components in steel structures because they transfer axial forces, shear forces and moments to the foundation. Exposed column bases are quite commonly used in low- to medium-rise buildings. To investigate shear transfer in exposed column base plates, four large scale specimens were subjected to a combination of axial load (compression or tension) and lateral shear deformations. The main parameters examined experimentally include the number of anchor rod, arrangement of anchor rod, type of lateral loading, and axial force ratio. It is observed that the shear resisting mechanism of exposed column base changed as the axial force changed. When the axial force is in compression, the resisting mechanism is rotation type, and the shear force will be resisted by friction force between base plate and mortar layer. The specimens could sustain inelastic deformation with minimal strength deterioration up to column rotation angle of 3%. The moment resistance and energy dissipation will be increased as the number of anchor rods increased. Moreover, moment resistance could be further increased if the anchor rods were arranged in details. When the axial force is in tension, the resisting mechanism is slip type, and the shear force will be resisted by the anchor rods. And the shear resistance was reduced significantly when the axial force was changed from compression to tension. The test results indicated that the current design approach could estimate the moment resistance within reasonable acceptance, but overestimate the shear resistance of exposed column base.

The Immediate Effects of Ankle Restriction Using an Elastic Band on Ground Reaction Force during a Golf Swing

  • Yi, Kyungock;Kim, OkJa
    • 한국운동역학회지
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    • 제26권2호
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    • pp.191-195
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    • 2016
  • Purpose: The purpose of this study was to analyze the immediate effects of ankle restriction with an elastic band on ground reaction force during a golf swing. Method: There were five subjects who were teaching pros with an average golf score of 75. A force platform (9281B, Switzerland) was used. The independent variable was the presence of an elastic band. The dependent variables were three-dimensional ground reaction forces to analyze the transfer of momentum with the timing, control and coordination of the three forces. A paired t-test within subject repeated measure design was used via an SPSS 20.0. Results: Wearing an elastic band around one's ankles significantly makes shorter time differences between the moment of cross anterior / posterior forces and vertical force and median value of anterior / posterior forces during the backswing, between medial and lateral maximum and anterior / posterior force from the top of the back swing to the mid down swing, and creates an anterior / posterior maximum force. Conclusion: Wearing an elastic band around one's ankles affects control and coordination between three dimensional forces, and anterior force power according to each phase of the golf swing.

Seismic performance of exterior R/C beam-column joint under varying axial force

  • Hu, Yanbing;Maeda, Masaki;Suzuki, Yusuke;Jin, Kiwoong
    • Structural Engineering and Mechanics
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    • 제78권5호
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    • pp.623-635
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    • 2021
  • Previous studies have suggested the maximum experimental story shear force of beam-column joint frame does not reach its theoretical value due to beam-column joint failure when the column-to-beam moment capacity ratio was close to 1.0. It was also pointed out that under a certain amount of axial force, an axial collapse and a sudden decrease of lateral load-carrying capacity may occur at the joint. Although increasing joint transverse reinforcement could improve the lateral load-carrying capacity and axial load-carrying capacity of beam-column joint frame, the conditions considering varying axial force were still not well investigated. For this purpose, 7 full-scale specimens with no-axial force and 14 half-scale specimens with varying axial force are designed and subjected to static loading tests. Comparing the experimental results of the two types of specimens, it has indicated that introducing the varying axial force leads to a reduction of the required joint transverse reinforcement ratio which can avoid the beam-column joint failure. For specimens with varying axial force, to prevent beam-column joint failure and axial collapse, the lower limit of joint transverse reinforcement ratio is acquired when given a column-to-beam moment capacity ratio.

String을 이용한 원형실린더 주위의 수평력 감소에 관한 연구 (Experimental Study on Reducing Lateral Force on Circular Cylinder Using Strings)

  • 백동일;조효제;이민준;임재환;이태경;김재희;오태원
    • 한국해양공학회지
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    • 제32권4호
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    • pp.237-243
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    • 2018
  • Recently, it was predicted that the size of offshore markets will grow as gas prices edge up. This paper presents experimental results for using strings as a suppression device on a circular cylinder and discusses the various data. A test model was used to investigate the role of strings by varying the thickness of the strings used to suppress a cylinder's lateral force taking into account the effect of turbulence promoted. A substantial amount of experimental data were taken from experiments performed on cylinders at Reynolds number up to a maximum value of $10^5$. The suppression of vortex shedding and a lateral force reduction of up to 70% were observed for the cylinder with strings.

AFS 횡력 제한조건 하에서 ESC와 AFS를 이용한 최적 요 모멘트 분배 (Optimum Yaw Moment Distribution with ESC and AFS Under Lateral Force Constraint on AFS)

  • 임성진;이정재;조성익
    • 대한기계학회논문집A
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    • 제39권5호
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    • pp.527-534
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    • 2015
  • 본 논문에서는 능동 전륜 조향장치(AFS)에 의한 횡력의 크기가 제한된 상황에서 자세 제어장치(ESC)와 능동 전륜 조향(AFS)을 이용한 통합 새시 제어기의 최적 요모멘트 분배 방법을 제안한다. 차량을 안정화시키는데 필요한 제어 요모멘트는 슬라이딩모드 제어이론을 이용하여 구한다. 가중 역행렬 기반 제어 할당 방법을 이용하여 제어 요모멘트를 ESC의 제동력과 AFS의 추가 조향각으로 분배한다. 저마찰 노면에서 AFS에 의한 횡력이 물리적 최대값을 초과하는 경우 제어 요모멘트를 제대로 만들어내지 못하므로 가중 역행렬 기반 제어 할당 방법을 이용하여 AFS에 의한 횡력의 크기를 제한하고 ESC의 제동력으로 부족한 제어 요모멘트를 보상하는 방법을 제안한다. 차량 시뮬레이션 패키지인 $CarSim^{(R)}$에서 시뮬레이션을 수행하여 AFS에 의한 횡력이 물리적 최대값을 초과하는 경우 제안된 방법이 차량의 조종 안정성과 횡방향 안정성을 향상시킨다는 사실을 검증했다.