• Title/Summary/Keyword: Tension deviation

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The effect of relax therapy on the change of facial temperature by D.I.T.I. (이완요법(弛緩療法)이 안면(顔面) 체열(體熱) 변화(變化)에 미치는 영향(影響))

  • Cho, Jung-Hoon;Lee, Kyung-Sub
    • Journal of Oriental Medical Thermology
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    • v.3 no.1
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    • pp.27-35
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    • 2004
  • Today, everybody lives in the stress. So 50% to 80% or 60% to 80% of the modern diseases are estimated what is caused by the stress. And one of the most important point of the stress is a too serious and continuos tension state. Therefore the best way to promotion, persistence, prevention and treatment of the modern man's health will be the relaxion from the tension state. The relax therapy as known as am effective method to the disease which as concerned with stress. that can be adapted to the treatment of anxiety-related diseases, insomnia, hypertension, tension headache, migraine, asthma, preparation of delivery, G-I disorders and menstrual disorders. Until now we guess the change of a relaxed state by the observation to the change of autonomic nervous system(ANS) and EEG. From the point of the ANS, sympathetic nervous system progresses slowly but parasympathetic nervous system increases the activity. In the EEG, both the alpha-wave concerned with the deep physical relaxed state and emotional stability and the theta-wave appeared in the state of meditation are increased. Current studies show that among the biochemical changes, especially serotinin like body hormone is increased by the feeling of the stability or the happiness. So, to see the change of the relaxed state in the image of the D.I.T.I., we used the deviational differences between the pre-relaxed state and the post-relaxed state of 70 people. As a result, the portional deviation of the face is decreased in the image of the D.I.T.I. So it can be thaught that we can determine the changes of the relaxed state by the D.I.T.I.

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Tension Estimation of External Tendons in PC Bridges Using Vibration Measurement Method (진동 측정법을 이용한 PC교량 외부텐던의 장력 추정)

  • Park, Sung Woo;Jung, Ha Tae;Jung, Soo Hyung
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.18 no.3
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    • pp.84-92
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    • 2014
  • In this study, vibrational tendon tension measurement methods are applied to estimate tension of external tendons used in segmental post-tensioned bridges. The acceleration of various length type of tendons is measured and natural frequencies are obtained using FFT (Fast Fourier Transform). The obtained natural frequencies are within 1% error regardless of sensor direction and location. On the basis of natural frequency of tendon, estimation of the tendon tension is performed by using many types of solutions such as string theory equation, multi mode estimation, practical formula estimation and stiff string with clamped-clamped boundary conditions. The results are compared with each other and have shown that the flexural stiffness is not negligible in tendons of this type causing the vibration mode to be inharmonically related. The results have shown that the method using stiff string equation with clamped-clamped boundary conditions is more accurate than the other methods. Application example of in-service bridges has shown that force distribution effects from friction at deviation blocks can be effectively detected.

Application of Strength Reduction Method to Evaluation of Pillar Safety Factor in very Closely Spaced Tunnels (근접병설터널에서 필라부 안전율 평가를 위한 강도감소법의 적용성 연구)

  • Jun, Sung-Kwon;Yoon, Dong-Ho;Song, Jae-Joon;Kim, Se Hyung
    • Tunnel and Underground Space
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    • v.29 no.5
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    • pp.346-355
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    • 2019
  • When evaluating pillar stability in very closely spaced tunnels, a local safety factor (strength/stress ratio) at the minimum width has been widely used. Tension bolts have been frequently applied as reinforcement for the cases where safety factors are less than 1.0 from FEM stress analysis. However, the local safety factor shows a constant value irrespective of the change in pillar width/tunnel diameter (PW/D) and the safety factor of the pillar is underestimated because the variation of deviation stress is relatively small even when the pre-stressing is applied to the tension bolt. In addition, the average safety factor proposed by Hoek and Brown(1980) was reviewed, but the pillar safety factor was relatively overestimated when the width of the pillar was increased. As an alternative, the SRM safety factor using shear strength reduction method shows the effect of changing the safety factor in the case of no reinforcement and tension bolt reinforcement as the pillar width/tunnel diameter(PW/D) changes. The failure shape is also similar to the previous limit theory result. In this study, the safety factor was evaluated without considering rock bolt and shotcrete to distinguish reinforcing effect of tension bolt.

Prediction of Optimal Catenary Tension by Dynamic Characteristic Measurement and Dynamic Analysis of Pantograph in High-Speed Train (고속열차 팬터그래프 동특성 측정 및 동역학 해석을 통한 최적 전차선 장력 예측)

  • Oh, Hyuck Keun;Yoo, Geun-Jun;Park, Tae-Won
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.11
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    • pp.350-356
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    • 2018
  • The contact force, which is the dynamic interaction between the pantograph and the catenary, is an important indicator for evaluating the current collecting quality, which is a stable power supply characteristic to the vehicle. In this study, dynamic contact force characteristics of pantograph of HEMU-430X vehicle, which is a power-distributed high-speed train test vehicle, were analyzed according to the catenary tension and compared with the analytical results using the pantograph-catenary interaction model. As a result of comparing the test results with the analytical results, it was confirmed that the average contact force and the standard deviation of the contact force, which are the main dynamic contact force characteristics, coincide relatively well. Using the analytical model, the relationship between the catenary tension and the contact force is presented according to the vehicle speed, and the optimal catenary tension for each operation speed is presented and compared with the international standard. As a result, it was found that the results obtained from the analysis are comparable to those recommended by international standards.

Study on the effect of cable on the lateral behavior of S-shaped Pedestrian-CSB (S형 보도사장교의 케이블이 횡방향 거동에 미치는 영향 연구)

  • Ji, Seon-Geun;Yhim, Sung-Soon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.5
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    • pp.577-584
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    • 2019
  • Recently, CSB(Cable-Stayed Bridge) have been attempted to be atypical forms for landscape elements in Korea. CSB with new geometry need to analyze their characteristics clearly to ensure structural safety. This study's bridge is the S-shaped curved pedestrian CSB that has a girder with S-shape plane curve and reverse triangular truss cross section, inclined independent pylon, modified Fan type main cable and vertical backstay cable. Curved CSB can have excessive lateral displacement and moment when the tension is adjusted, focusing only on longitudinal behavior, such as a straight CSB. In order to analyze the effect of the cable on the lateral behavior of bridges, the cable is divided into two groups according to the lateral displacement direction of the pylon due to tension. The influence of the combination ratio of GR1 and GR2 on the girder, bearing, pylon, and vertical anchor cable was analyzed. When the tension applied to the bridge is 1.0GR1 plus 1.0GR2, In the combination of 1.2GR1 plus 0.8GR2, the stress on the left and right upper member of the truss girder and the deviation of the both were minimized. In addition, the horizontal force of the bearing, the lateral displacement and moment of the pylon, and the tension of the vertical backstay cable also decreased. This study is expected to be used as basic data for determination of tension of CSB with similar geometry.

Debonding failure analysis of prestressed FRP strengthened RC beams

  • Hoque, Nusrat;Jumaat, Mohd Z.
    • Structural Engineering and Mechanics
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    • v.66 no.4
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    • pp.543-555
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    • 2018
  • Fiber Reinforced Polymer (FRP), which has a high strength to weight ratio, are now regularly used for strengthening of deficient reinforced concrete (RC) structures. While various researches have been conducted on FRP strengthening, an area that still requires attention is predicting the debonding failure load of prestressed FRP strengthened RC beams. Application of prestressing increases the capacity and reduces the premature failure of the beams largely, though not entirely. Few analytical methods are available to predict the failure loads under flexure failure. With this paucity, this research proposes a method for predicting debonding failure induced by intermediate crack (IC) for prestressed FRP-strengthened beams. The method consists of a numerical study on beams retrofitted with prestressed FRP in the tension side of the beam. The method applies modified Branson moment-curvature analysis together with the global energy balance approach in combination with fracture mechanics criteria to predict failure load for complicated IC-induced failure. The numerically simulated results were compared with published experimental data and the average of theoretical to experimental debonding failure load is found to be 0.93 with a standard deviation of 0.09.

Development and application of the new ASC system in No.2 cold rolling mill (2 냉연 신형상제어 시스템 개발 및 적용)

  • 박남수;심민석
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.1068-1071
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    • 1996
  • Good shape on flat rolled product is necessary to meet today's customer quality requirement. To meet the increasing demand in quality of strip shape from downstream customers, POSCO has replaced the Automatic Shape Control(ASC) system with the existing one that had used noncontact type measuring system at No.2 Cold Rolling Mill, Pohang works in October, 1995. The strip shape is influenced by the profile, roll crown, bending control, skew control system, as well as work roll cooling system. We have used ASC to adjust those factors in Cold Rolling Mill that could get a satisfactory result, almost less than .+-.5 1-unit deviation from the target shape. However, the downstream customer(i.e. Continuos Annealing Line) wants a good shape not only at the moment of exit of roll bite, but after rolling without tension. In this investigation, the difference will be discussed and how deal with this problem.

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Effect of Slurry Property on Preparation of Zirconia Film in Electrophoretic Deposition (전착법에서 용액특성이 지르코니아 막형성에 미치는 영향)

  • 김상우;이병호;손용배;송휴섭
    • Journal of the Korean Ceramic Society
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    • v.36 no.9
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    • pp.991-996
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    • 1999
  • Effect of solution property on the weight varation and microstructural change of film was studied by electrophoretic deposition in order to obtain a homogeneous and dense zirconia film. As a result of weight kinetics of film which obtained in alcohol or aqueous solution having different polarity experimental data showed large deviation from theoretical ones calculated by Zhang's kinetic model. It had been shown that the weight affecting factors was largely dependent on properties other than dielectric constant and viscosity of solvent zeta potential appiled field and time. In initial stage a main factor of the drastic weight increase was the capillary drag of porous substrate. The cause of weight decrease with time in aqueous solution after 300 s was attributed to the defect of film by sagging and electrolytic reaction. The electrolyte film which prepared in alcohol solution with good wetting for substrate had better homogeneous and dense microstructure than one in aqueous solution with high surface tension.

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Design of a robust gauge controller for a single-stand cold rolling mill (단일 스탠드 냉간 압연 공정을 위한 견실한 두께 제어기의 설계)

  • An, Hyeon-Sik;Yun, Tae-Ung;Kim, Gwang-Bae
    • Journal of Institute of Control, Robotics and Systems
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    • v.2 no.3
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    • pp.134-141
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    • 1996
  • In this paper, we formulate the mathematical model for a single-stand rolling mill and design control systems for the thickness control at the exit of roll stand and for the tension control of the strip in the process. We propose a thickness controller based on the Internal Model Control structure which can be an effective application when the frequency components of the thickness deviation of the entry strip are known and, show how it can be appropriately combined with BISRA AGC method for a precise thickness control while maintaining the robustness against the modeling error of the mill modulus. It is illustrated by simulations that the proposed thickness control method gives better performance than existing methods and has the robustness against the modeling error of the mill modulus as well.

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The Study for Seismic Performance Evaluation Using SN Steel (건축구조용 압연강재(SN)를 이용한 내진성능평가에 관한 연구)

  • Oh, Sang-Moon;Ryu, Hong-Sik;Kim, Young-Ju;Chang, In-Hwa
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2006.03a
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    • pp.241-248
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    • 2006
  • By Testing tension coupon, deviation of yield strength & tensile strength of SS and SM is big but the that of SN is small relatively. So Designing weak beam type frame by using SN could be reflected well the original intention. As the strength ratios of beam and column becomes large, the absorption energy is large. The increase quantity was linear relationship, the y=0.46x+0.62 $(R^2=0.82)$

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