• 충청수학회지
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• 제24권2호
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• pp.239-245
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• 2011

In this paper, we will study the tension field of the function related to a Riemannain submersion ${\pi}\;:\;N{\rightarrow}M$ with totally geodesic fibres. In case that the Riemannain submersion ${\pi}\;:\;N{\rightarrow}M$ particularly has a smooth map $f\;:\;M{\rightarrow}N$ which happens to be a section, we will show that tension field ${\tau}(f)$ of the energy functional can be decomposed into the horizontal and vertical parts.

• 한국농공학회논문집
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• 제52권2호
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• pp.11-17
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• 2010

For the reasonable analysis of design problems for agricultural facilities, considered the reinforcing effect of thin-wall. The most of agricultural structure is constructed small scale and have many purposes. Thus it has been designed temporary rather than permanent structure, and has relatively large slenderness ratio, small section and semi-rigid condition. Therefore many agricultural facilities are consist of relatively strong frame with weak wall at the viewpoint of stiffness and have not been reflected in the design. But the tension field influences to collapse of structure have already known. Therefore, we need quantification the effect of tension field at structural analysis. In this study, present the method of quantification the effect of tension field that came out thin-plate surrounded by high stiffness frame. The numerical results show that the effect of tension field effect for thin-wall is about 5% of the sectional area of frame in study agricultural facilities.

• 콘크리트학회논문집
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• 제12권6호
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• pp.57-66
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• 2000

The truss analogy for the analysis of beam-columns subjected of shear and flexure is limited by the contribution of transverse and longitudinal steel and diagonal concrete compression struts. However, it should be noted that even though the behavior of reinforced concrete beam-columns after cracking can be modeled with the truss analogy, they are not perfect trusses but still structural elements with a measure of continuity provided by a diagonal tension field. The mere notion of compression field denotes that there should be some tension field coexisting perpendicularly to it. The compression field is assumed to form parallel to the crack plane that forms under combined flexure and shear. Therefore, the concrete tension field may be defined as a mechanism existing across the crack and resisting crack opening. In this paper, the effect of concrete tensile properties on the shear strength and stiffness of reinforced concrete beam-columns is discussed using the Gauss two-point truss model. The theoretical predictions are validated against the experimental observations. Although the agreement is not perfect, the comparison shows the correct trend in degradation as the inelasticity increases.

• 한국산학기술학회논문지
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• 제22권4호
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• pp.295-311
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• 2021

본 연구에서는 사장교 케이블에 대한 장력계측장치의 현장적용성에 대한 실험을 수행하였다. 사장교 케이블의 장력을 추정하기 위해서 진동법을 이용하였으며 대상교량에 대해서 케이블의 가진을 통해서 모드특성을 분석하였고 케이블의 장력을 추정하기 위한 계측장치로는 GTDL360, NI Module, 9 Axes Motion Sensor등을 적용하였고 5개의 대상교량에 대해서 상기 계측장치들을 이용하여 케이블의 모드특성을 분석하여 케이블장력측정실험의 적정성을 평가하고 케이블의 장력을 추정하였다. 또한 5개의 대상교량에 대해서 수치해석을 실시하여 케이블의 고유진동수 및 케이블장력을 해석하였다. 현장 계측결과에 의한 케이블의 추정장력과 수치해석에 의한 케이블의 추정장력을 비교하여 현장계측방법의 적정성을 판단하였으며 분석결과 현장 계측에 의한 케이블의 계측장력과 해석에 의한 추정장력은 오차범위내에 있어서 상기 계측장치들을 현장에 적용하여도 무방할 것으로 판단된다. 현장실증교량의 가속도 기반의 케이블 추정장력과 수치해석에 의한 해석장력과의 값을 비교분석한 결과 값이 허용범위 내로 가속도 기반의 케이블 추정장력값은 적정한 것으로 판단된다. 또한, 현장적용성 분석결과 센서의 설치위치 및 기상조건의 제한 등 계측장치의 한계점이 존재하므로 추후 케이블 스마트 장력계측시스템에 관한 지속적인 후속연구가 필요할 것으로 판단된다.

• Steel and Composite Structures
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• 제10권1호
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• pp.87-108
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• 2010

A Steel Plate Shear Wall (SPSW) is a lateral load resisting system consisting of an infill plate located within a frame. When buckling occurs in the infill plate of a SPSW, a diagonal tension field is formed through the plate. The study of the tension field behavior regarding the distribution and orientation patterns of principal stresses can be useful, for instance to modify the basic strip model to predict the behavior of SPSW more accurately. This paper investigates the influence of torsional and out-of-plane flexural rigidities of boundary members (i.e. beams and columns) on the buckling coefficient as well as on the distribution and orientation patterns of principal stresses associated with the buckling modes. The linear buckling equations in the sense of von-Karman have been solved in conjunction with various boundary conditions, by using the Ritz method. Also, in this research the effects of symmetric and anti-symmetric buckling modes and complete anchoring of the tension field due to lacking of in-plane bending of the beams as well as the aspect ratio of plate on the behavior of tension field and buckling coefficient have been studied.

• Journal of Advanced Marine Engineering and Technology
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• 제27권7호
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• pp.826-831
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• 2003

The purpose of this study was to measure the surface tension of hard water through electro-magnetic field for investigating the effect of electro-magnetic water treatment. The maximum reduction of surface tension was 8% comparing to the no treatment case. When the flow velocity through the permanent magnetic device (PMD) was 6.3 m/s, sample of hard water had the minimum surface tension.

• International Journal of Concrete Structures and Materials
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• 제10권2호
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• pp.143-147
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• 2016

In recent years, some modifications were introduced in the stress-strain relationship of the steel in order to develop a more efficient shear model for reinforced concrete members. The last contribution in this sense corresponding to the Refined Compression Field Theory (RCFT, 2009); this theory proposed a steel constitutive model that has account the tension stiffening area prescribed by technical codes, what simplifies all the design process. However, under certain design conditions supported by such codes, the RCFT model does not provide a real (non-complex) solution for the steel yield strain when the prescribed tension stiffening area is considered; then the load-strain response cannot be computed. In this technical note, the tension stiffening area is fixed in order to guarantee the application of the embedded steel constitutive model for all the standard design range.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.316-316
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• 2000

SPM dynamic model was developed by using Bland & Ford formulas considered elastic zone in roll gap, gauge meter equation, tension equation, speed equation and actuator models. And SPM controllers of the field were done model ing. It was shown the efficiency of constant tension, rol1ing force and elongation controllers by the simulation program and it was recommended the proper gain to the controllers of the field.

• 한국지반공학회논문집
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• 제24권11호
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• pp.143-155
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• 2008

지반앵커는 그라우트가 힘을 받는 형태에 따라 분류되는데 앵커의 인발시 그라우트가 인장을 받으면 인장형 앵커로 압축을 받으면 압축형 앵커로 분류된다. 본 연구에서는 인장과 압축을 동시에 받는 기구를 가진 복합형 앵커를 개발하였다. 현장시험을 위해 연약지반내의 앵커체 내부에 변형률게이지를 설치하였고, 측정된 시험결과를 통해 인장과 압축변형률이 동시에 발생하는 인발저항기구를 관찰할 수 있었다.

• Smart Structures and Systems
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• 제12권3_4호
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• pp.465-482
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• 2013

Recently, a novel stress sensor, which utilizes the elasto-magnetic (EM) effect of ferromagnetic materials, has been developed to measure stress in steel cables and wires. In this study, the effectiveness of this EM based stress sensors for monitoring of the cable tension force of a real scale cable-stayed bridge was investigated. Two EM stress sensors were installed on two selected multi-strand cables in Hwa-Myung Bridge, Busan, South Korea. Conventional lift-off test was conducted to obtain reference cable tension forces of two test cables. The reference forces were used to calibrate and validate cable tension force measurements from the EM sensors. Tension force variations of two test cables during the second tensioning work on Hwa-Myung Bridge were monitored using the EM sensors. Numerical simulations were conducted to compare and verify the monitoring results. Based on the results, the effectiveness of EM sensors for accurate field monitoring of the cable tension force of cable-stayed bridge is discussed.