• 제목/요약/키워드: Static Measurement

검색결과 710건 처리시간 0.028초

풍화암 소켓 대구경말뚝의 축하중 전이거동 (Axial Load Transfer Behavior of a Large Diameter Pile socketed into weathered rock)

  • 정창규;임태경;황근배;최용규
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2002년도 가을 학술발표회 논문집
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    • pp.390-397
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    • 2002
  • In this study, static pile load tests with load transfer measurement for a pile socketed into weathered rocks were performed. Axial load transfers during static pile load test were measured and analyzed. Three large diameter piles socketed into weathered rock were behavior behaved as friction pile.

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Static measurement of yield stress using a cylindrical penetrometer

  • Uhlherr, P.H.T.;Guo, J.;Fang, T.N.;Tiu, C.
    • Korea-Australia Rheology Journal
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    • 제14권1호
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    • pp.17-23
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    • 2002
  • A novel and simple method using a cylindrical penetrometer is being developed for the measurement of yield stress. The principle of this technique is based on the measurement of the static equilibrium of a falling penetrometer in a yield stress fluid. The yield stress is simply determined by a balance of forces acting on the penetrometer. The yield stress of Carbopol gels and $TiO_2$ suspensions has been measured using this method. The results are in reasonable agreement with the values from conventional methods. The effects of the dimensions and weight of the penetrometer have been examined. The long-term behaviour was also observed. No measurable creep was seen and equilibrium was found to be very quickly established. The cylindrical penetrometer technique promises to be a simple, quick and reliable static method for the measurement of yield stress.

정적 자세에서 하지정렬 측정방법에 관한 고찰 (Measurement Methods of Lower Extremity Alignment in Static Posture)

  • 공희경;조현래;배성수
    • The Journal of Korean Physical Therapy
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    • 제15권1호
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    • pp.1-8
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    • 2003
  • We need to study about lower extremity alignment because the structure dictates the function of lower extremity. Through lower extremity alignment assessment in static posture, we recognize abnormal structural conditions which could affect dynamic motion such as gait. To evaluate of lower extremity alignment provide so many useful information, but method of measurement is so limited. Therefore, this review will assist understanding for measurement of lower extremity alignment in static posture. From now on study about the objective measurement method must be achieved much more in physical therapy.

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A Study on the Cost-Effective Personalized Plantar Pressure Measurement System

  • Kang, Ji-Woo;Kwon, Young-Man;Lim, Meoung-Jae;Chung, Dong-Kun
    • International Journal of Internet, Broadcasting and Communication
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    • 제11권4호
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    • pp.11-17
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    • 2019
  • Plantar pressure data can be used not only for walking patterns in daily life, but also for eating, health care, and disease prevention. For this reason, the importance of plantar pressure measurement has recently increased. However, most systems that can measure both static and dynamic plantar pressure at the same time are expensive, not portable, and not universal. In this study, we propose a system that effectively reduces the number of sensors in plantar pressure system. Through this, we want to increase the economics and practicality by reducing the size and weight of the system, as well as the power consumption. First, for static plantar pressure and dynamic plantar pressure, the values measured by existing precision instruments are analyzed to determine how many measurement parts the insole is divided into. Next, for the divided measuring parts, the position of the sensor is determined by calculating the Center of Pressure (COP) for each part with the values of all dynamic and static plantar pressure sensors. Finally, in order to construct a personalized plantar pressure measurement system, we propose a weighting method for the static plantar pressure COP and the dynamic plantar pressure COP for each part.

Health Monitoring of High-rise Building with Fiber Optic Sensor (SOFO)

  • Mikami, Takao;Nishizawa, Takao
    • 국제초고층학회논문집
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    • 제4권1호
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    • pp.27-37
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    • 2015
  • Structural health monitoring is becoming more and more important in the domain of civil engineering as a proper mean to increase and maintain the safety, especially in the land of earthquakes like Japan. In many civil structures, the deformations are the most relevant parameter to be monitored. In this context, a monitoring technology based on the use of long-gage fiber optic deformation sensor, SOFO is being applied to a 33-floors tall building in Tokyo. Sensors were installed on the $2^{nd}$ floor's steel columns of the building on May 2005 in the early stage of the construction. The installed SOFO sensors were dynamic compatible ones which enable both static and dynamic measurements. The monitoring is to be performed during the whole lifespan of the building. During the construction, static deformations of the columns had been measured on a regular basis using a reading unit for static measurement and dynamic deformation measurements were occasionally conducted using a reading unit for dynamic measurement. The building was completed on August 2006. After the completion, static and dynamic deformation measurements have been continuing. This paper describes a health monitoring technology, SOFO system which is applicable to high-rise buildings and monitoring results of a 33-floors tall building in Tokyo from May 2005 to October 2010.

Dynamic and static structural displacement measurement using backscattering DC coupled radar

  • Guan, Shanyue;Rice, Jennifer A.;Li, Changzhi;Li, Yiran;Wang, Guochao
    • Smart Structures and Systems
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    • 제16권3호
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    • pp.521-535
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    • 2015
  • Vibration-based monitoring is one approach used to perform structural condition assessment. By measuring structural response, such as displacement, dynamic characteristics of a structure may be estimated. Often, the primary dynamic responses in civil structures are below 5 Hz, making accurate low frequency measurement critical for successful dynamic characterization. In addition, static deflection measurements are useful for structural capacity and load rating assessments. This paper presents a DC coupled continuous wave radar to accurately detect both dynamic and static displacement. This low-cost radar sensor provides displacement measurements within a compact, wireless unit appropriate for a range of structural monitoring applications. The hardware components and operating mechanism of the radar are introduced and a series of laboratory experiments are presented to assess the performance characteristics of the radar. The laboratory and field experiments investigate the effect of factors such as target distance, motion amplitude, and motion frequency on the radar's measurement accuracy. The results demonstrate that the radar is capable of both static and dynamic displacement measurements with sub-millimeter accuracy, making it a promising technology for structural health monitoring.

다점 피토관을 이용한 기체 유량 측정의 불확도 평가 (Uncertainty Assessment of Gas Flow Measurement Using Multi-Point Pitot Tubes)

  • 양인영;이보화
    • 한국유체기계학회 논문집
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    • 제19권2호
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    • pp.5-10
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    • 2016
  • Gas flow measurement in a closed duct was performed using multi-point Pitot tubes. Measurement uncertainty was assessed for this measurement method. The method was applied for the measurement of air flow into a gas turbine engine in an altitude engine test facility. 46 Pitot tubes, 15 total temperature Kiel probes and 9 static pressure tabs were installed in the engine inlet duct of inner diameter of 264 mm. Five tests were done in an airflow range of 2~10 kg/s. The flow was compressible and the Reynolds numbers were between 450,000 and 2,220,000. The measurement uncertainty was the highest as 6.1% for the lowest flow rate, and lowest as 0.8% for the highest flow rate. This is because the difference between the total and static pressures, which is also related to the flow velocity, becomes almost zero for low flow rate cases. It was found that this measurement method can be used only when the flow velocity is relatively high, e.g., 50 m/s. Static pressure was the most influencing parameter on the flow rate measurement uncertainty. Temperature measurement uncertainty was not very important. Measurement of boundary layer was found to be important for this type of flow rate measurement method. But measurement of flow non-uniformity was not very important provided that the non-uniformity has random behavior in the duct.

변형률 측정을 이용한 추진기관용 Al 합금의 파괴인성 평가 (Evaluation of Fracture Toughness of Al alloys for Propulsive Engine using Strain Measurement)

  • 김재훈;김덕회;임동규;박성욱;문순일
    • 한국안전학회지
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    • 제17권3호
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    • pp.13-21
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    • 2002
  • The tincture toughness is evaluated by using U(compact tension) and 3PB(three point bending) specimens of AI alloys far propulsive engine. To evaluate the static fracture toughness, strain gage method is used. The static fracture toughness obtained from the strain measurement is compared with the results by ASTM standard and FEM analysis. For the reliable evaluation of fracture toughness, strain gages are attached at various positions.

영상처리를 이용한 정동적 변위 계측과 속도, 가속도 추산방식 연구 (Measurement of Static and Dynamic Displacement by Image Processing and Study for Prediction Method of Velocity and Acceleration)

  • 허석;곽문규;이호범
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2010년도 추계학술대회 논문집
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    • pp.527-532
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    • 2010
  • This paper is concerned with the measurement of static and dynamic displacement by image processing(IP) and study for prediction method of velocity and acceleration. To measure the displacement visually, the measurement system consists of a telephoto zoom camera, ccd image device and a computer. The specific target on the white board is used to calculate the displacement of the structure. The captured image is then converted into a pixel-based data and then analyzed numerically. The limitation of the system depends on the image capturing speed and the pixel-size of image. In this paper, we developed for the displacement measurement using the image processing method. The proposed method enables us to measure the vibration measurement, velocity and acceleration directly without any contact. The current resolution of the displacement measurement is limited to 1/100 millimeter scale.

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레이저 간섭계에 의한 테이블의 처짐측정과 FEA에 의한 이의 검증 (A Study on the measurement of Table Deflection using Laser Interferometer and It's Inspection using FEA)

  • 이승수
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 1998년도 추계학술대회 논문집
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    • pp.204-209
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    • 1998
  • The acceleration of the performance of machine tools influences the development of the semi-conductor and optical technology as the development of NC and measurement technology. We can mention that a traction role of the acceleration for the development like that depends on the development of the measurement technics Stylus instrument method, STM, SEM, Laser interferometer method which are used for measuring the quasi-static error of machine tools. Because the measurement has been done to unload condition without considering of mechanical stiffness in the case of machining center as we measure the quasi-static error of machine tools on general studies, people who works on the spot has many problems on the data value. Therefor we will help working more accurately on the spot by measuring, analyzing, displaying the deflection of the table and support shaft when we load on the table and the support shaft of machining center using laser interferometer. Also we try to settle new conception of the measurement method and more accurate grasp of the deflection tendency by verifing the tendency of the error measured through the comparison of the simulated error using ANSYS, a common finite element analysis program, which is able to measure heat deformation, material deformation, and error resulted form this study.

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