• Title/Summary/Keyword: transverse test

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Confinement of Columns using Headed Bars (Headed Bars를 활용한 기둥의 구속효과에 대한 연구)

  • 김영훈;윤영수;데니스미첼
    • Proceedings of the Korea Concrete Institute Conference
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    • 2002.05a
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    • pp.929-934
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    • 2002
  • Eight full-scale columns were constructed and tested under monotonic axial compression loading to investigate the influence of headed bars on the confinement of the concrete. One column represented a column with no transverse reinforcement and another column had poor detailing and little confinement. A third column contained seismic hoops and crossties, which represented current detailing practice for significant confinement. A fourth column test is conducted to investigate the response with the seismic crossties replaced by headed bars. Two column specimens were constructed and tested with all of the transverse reinforcement provided by headed bars. These six specimens enabled an assesment of the effectiveness of headed bars in confining the concrete. It was found that the use of headed bars improved the confinement of the columns. Two additional specimens were constructed without any transverse reinforcement. These columns were later retrofitted, by drilling horizontal holes in the columns, adding special headed bars (one head fixed and the other head threaded) and then filling the drilled holes with epoxy. These retrofitted specimens with these added headed bars provided insight into the rehabilitation of older structures containing poorly detailed columns. All of the test specimens were instrumented to determine strain localization during failure and to monitor the strain in the longitudinal and transverse reinforcement.

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Measurement of aerodynamic coefficients of tower components of Tsing Ma Bridge under yaw winds

  • Zhu, L.D.;Xu, Y.L.;Zhang, F.;Xiang, H.F.
    • Wind and Structures
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    • v.6 no.1
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    • pp.53-70
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    • 2003
  • Tsing Ma Bridge in Hong Kong is the longest suspension bridge in the world carrying both highway and railway. It has two H-shape concrete towers, each of which is composed of two reinforced concrete legs and four deep transverse prestressed concrete beams. A series of wind tunnel tests have been performed to measure the aerodynamic coefficients of the tower legs and transverse beams in various arrangements. A 1:100 scaled 3D rigid model of the full bridge tower assembled from various tower components has been constructed for different test cases. The aerodynamic coefficients of the lower and upper segments of the windward and leeward tower legs and those of the transverse beams at different levels, with and without the dummy bridge deck model, were measured as a function of yaw wind angle. The effects of wind interference among the tower components and the influence of the bridge deck on the tower aerodynamic coefficients were also investigated. The results achieved can be used as the pertinent data for the comparison of the computed and field-measured fully coupled buffeting responses of the entire bridge under yaw winds.

Dynamic Test method to Determine Modulus of Elasticity of Sound Insulating Coat (현장 타설용 고분자 감쇠재의 탄성 계수를 측정하기 위한 실험 기법)

  • Yemam, Dinberu Molla;Yi, Chongku
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2015.05a
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    • pp.92-93
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    • 2015
  • The main purpose of this paper is to present the dynamic test method developed for measuring the elastic modulus of sound insulating coat. The test setup was devised based on the theoretical natural frequency of a simply-supported beam subject to free transverse vibration. A stainless steel beam was tested and the result showed a good compliance with the standard value listed in literatures. The result indicates that the test set up can serve as a quick, economical and suitable scheme to test non self-supporting materials.

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Evaluation of Tensile Properties of Carbon Fiber Reinforced Composite Laminates with Non-Woven Carbon Mat (부직포를 삽입한 탄소섬유강화 복합적층판의 인장특성 평가)

  • 정성균
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.6 no.4
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    • pp.96-100
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    • 1997
  • Tensile properties of carbon fiber reinforce composite laminates with non-woven carbon mat are evaluated in this paper. Composite laminates are made by inserting non-wovon carbon mat between layers, The specimens were cut and polished according to ASTM standard . Longitudinal and Transverse Young's modulus are obtained by tensile test. Young's moduli without non-woven carbon mat are compared with those with non-woven carbon mat. Longitudinal and Transverse tensile strength are also investigated. Experimental results show that the transverse Young's modulus of composite materials with non-woven carbon mat is about 10% higher than that of composite materials without non-woven carbon mat. Longitudinal tensile strength of composite materials with non-woven carbon mat is about 24% higher than that of composite materials without non-woven carbon mat. Transverse tensile strength and torughness also increase by inserting non-woven carbon mat between layers.

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Measurement of Transverse Strain Using Polarization Maintaining Fiber Bragg Grating Sensor (편광 유지 광섬유 브래그 격자 센서를 이용한 횡방향 변형률 측정)

  • Yoon, Hyuk-Jin;Kim, Dae-Hyun;Hong, Chang-Sun;Kim, Chun-Gon
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.31 no.6
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    • pp.30-35
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    • 2003
  • In this paper, the transverse strain was measured using polarization maintaining fiber Bragg grating(PMFBG) sensor. PMFBG sensor was fabricated using phase mask and Excidmer laser. The reflected wavelength of PMFBG sensor had dual peaks due to intrinsic birefringence. To find the polarization axes, peak sensitivity was measured under compression test. The signal characteristics of PMFBG sensor were also examined in embedding condition. The embedded PMFBG sensor in epoxy block was loaded for the transverse strain measurement, The wavelength-swept fiber laser(WSFL) was used to construct the PMFBG sensor system. Experiments showed that the PMFBG sensor could successfully measure the transverse strain.

Experimental Study on Strengthening Transverse Joints between Precast Concrete Slabs

  • Park, Jong-Jin;Cheung, Jin-Hwan;Shin, Su-Bong
    • KCI Concrete Journal
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    • v.12 no.2
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    • pp.45-54
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    • 2000
  • Precast R.C. slabs are being used widely for the construction of bridge structures due to their simplicity in construction processes. However, one of the disadvantages in precast R.C. slabs is the existence of transverse joints between two precast slabs. The transverse joints are structurally fragile and the task of strengthening the joints is difficult one due to their structural discontinuity. The aim of this study was to improve the behavior of transverse joints between precast R.C. slabs by introducing prestress with external cables. Three steel-concrete composite bridge specimens, which were prestressed with the external cables anchored on steel girders, were fabricated in the laboratory. Both pretension and post-tension methods were applied to introduce prestressing on the concrete slab with a straight tendon arrangement. Static tests were conducted at service load and ultimate load test was performed to evaluate punching shear capacity of the transverse joint. In this paper, two prestressing methods were tested and their effects were evaluated with respect to the elastic behavior and ultimate loading capacity of the transverse joints.

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The Study of Vertebral Palpation (척추부 촉진에 관한 연구)

  • Park, Youn-Ki
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.16 no.1
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    • pp.57-63
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    • 2010
  • The palpation of spinous process and transverse process of vertebra are important part of the assesment and treatment from Orthopedic manual therapy. But the palpation area is descriptive differently each of literatures. So we generally got these outcomes. : There are C2, C3, C4 and C6 process as a bony landmarks and these are important part of establish the precise location of pain appears from cervical spine. Even though C7 process regard a prominent part, it is hard to distinguish C6 and process of T1. Thru that differentiation, grab the patient's forehead and try them cervical and hyper-extension check any movement of process or put on the fingers on C7 preocess and check the movement. The palpation of thoracic spine process is the land mark which determines general level orientation in the spine easily, there are T2, T7 spinous process. However, It is depends on how do you test the patient's arm when you palpate it and it can effect on spinous process. The transverse process of C1 is the only spot for palpation in cervical spine, and T1-3, T12 transverse process can palpate it when it stands on the process. The end of T4-6, T11 is placed on middle on vertebra of transverse process and transverse process. T7-9, T10 transverse process is place on same position as spinous process which is upper part of the spine.

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Effects of Transverse Reinforcement on Headed Bars with Large Diameter at Cut-off Points (컷오프 구간에 정착된 대구경 확대머리철근에 대한 횡보강근의 효과)

  • Jung, Hyung-Suk
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.22 no.5
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    • pp.82-90
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    • 2018
  • The nuclear structures are composed of large diameter bars over No.36. If the hooked bars are used for anchorage of large diameter bars, too long length of the tail extension of the hook plus bend create congestion and make an element difficult to construct. To address those problems, headed bars were developed. Provisions of ACI 318-08 specify the development length of headed bars and ignore the effect of transverse reinforcement based on the background researches. However, if headed bars are used at the cut-off or lap splice, longitudinal reinforcements, which are deformed in flexural members, induce tensile stress in cover concrete and increase the tensile force in the transverse reinforcement. The object of this research is to evaluate the effects of transverse reinforcement on the anchorage capacity of headed bar so anchorage test with variable of transverse rebar spacing was conducted. Specimens, which can consider the behavior at the cut-off, were tested. Test results show that failure of specimen without transverse reinforcement was sudden and brittle with concrete cover lifted and developed stress of headed bars was less than half of yield strength of headed bars. On the other hand, in the specimen with transverse reinforcement, transverse rebar directly resist the load of free-end so capacity of specimens highly increased.

Fracture Toughness Embrittlement by Hydride in Zr-2.5Nb Pressure Tube (Zr-2.5Nb 압력관의 수화물에 의한 파괴인성 취화에 관한 연구)

  • Oh, Dong-Joan;Ahn, Sang-Bok;Park, Soon-Sam;An, Chang-Yun;Kim, Young-Suk
    • Proceedings of the KSME Conference
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    • 2000.11a
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    • pp.93-98
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    • 2000
  • Unpredictable failures can occur due to the DHC (delayed hydride cracking) or the degradation of fracture toughness by hydride embrittlement in CANDU pressure tube which can result from the absorption of hydrogen or deuterium in the high temperature coolant. To investigate the hydride embrittlement of CANDU Zr-2.5Nb pressure tube, the transverse tensile test and the fracture toughness test were performed from room temperature to $300^{\circ}C$ using three different specimens which have an AR (As Received), 100, and 200 ppm hydrogen. As the amount of absorbed hydrogen was increased, the transverse yield strength and the ultimate tensile strength were also increased. In addition, as the test temperature became higher they were decreased linearly. While, at room temperature, the hydrogenbsorbed specimens represented the embrittlement which resulted in sudden decreasing of fracture toughness, the fracture characteristics became ductile such as AR specimen at high temperatures. Through the observation of fracture surface using SEM, it was found that the stress state of mixed mode could be related to the fissure which was believed to decrease the global fracture toughness.

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Resistive breathing exercise using transverse abdominis strengthening and P.N.F affects pulmonary functions and static sitting posture of adult stroke patient : a case report (복횡근의 강화운동과 고유수용성신경근촉진법을 이용한 호흡저항운동이 뇌졸중 환자의 폐기능과 정적인 앉은자세에 미치는 영향 : 증례보고)

  • Lee, Byung-Ki
    • PNF and Movement
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    • v.8 no.3
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    • pp.49-54
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    • 2010
  • Pupose : This study aimed to examine the Influence of stregthening for Transverse abdominis and resistive breathing exercise to use PNF on fulmonary functions and static sitting posture in adult stroke patient. Methods : Left hemi-plegic patient was masured pulmonary function test and analyzed sitting posture of alignment at pre intervention and post-intervention in 4weeks. Results : The pulmonary functions was increased and changed good alignment of trunk on sitting position after treatments. Conclusion : We were found that stregthening for Transverse abdominis and resistive breathing exercise to use PNF could improve pulmonary functions and sitting posture for stroke patient.

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