• Title/Summary/Keyword: tension shift

Search Result 37, Processing Time 0.021 seconds

Study on LSDC Design for Coiling Shape Control of Hot Strip Mills (열간압연 권취형상 제어를 위한 LSDC 설계에 관한 연구)

  • Lee, Sang Ho;Park, Hong Bae;Park, Cheol Jae
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.21 no.9
    • /
    • pp.869-874
    • /
    • 2015
  • We developed an LSDC (Load Shift and Load Distribution Control) technology in order to improve coil quality and productivity by reducing tension fluctuation especially for the tail of the strip in the down coiler in hot strip mills. To adapt the new controller, the torque and speed distribution between the zero pinch roll, pinch roll, and mandrel are needed. The proposed controller is a combination of an LSC to share the tension between the mill stand and the mandrel, and an LDC to shift the torque load from the zero pinch roll to the pinch roll. From the simulation, the proposed controller is verified under the torque disturbance. Using a field test, the torque deviation decreased by nearly 50% through utilization of the LSDC control.

Analysis of Tension Mask Thermal Deformations under Localized Heating and Prediction of Electron Beam Landing Shifts (국부가열에 의한 Tension Mask 의 열변형 해석 및 전자빔의 오착 예측)

  • Shin, Woon-Seo;You, Se-Jonn;Jang, Bo-Woong
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.16 no.8
    • /
    • pp.138-148
    • /
    • 1999
  • Thermal deformations of tension mask under localized heating are analyzed using finite element method and electron beam landing shifts are predicted by the analysis results. In CRT, electron beam landing shifts due to thermal deformations of the tension mask make the color purity of screen worse. In order to get the final results of thermal deformations, firstly the tension processes of the mask and following welding processes between the tensional mask and rail must be analyzed sequentially. And then, nonlinear transient thermo-elastic finite element analysis is performed on every part inside CRT including tension mask, wherein thermal radiation is a main heat transfer mechanism. Because the tension mask has numerous slits, the effective thermal conductivity and effective and effective elastic modulus is calculated, and the tension mask is modeled as a shell without slits. From the displacement results of tension mask, electron beam landing shifts is calculated directly. Experiments are performed to confirm our analysis results. Temperature distributions and beam landing shifts of tension mask are measured and the results are in good agreement with those of analyses.

  • PDF

Effect of Heat Treatment Process on the Shadow Mask Tension (세도우 마스크 장력에 열공정이 미치는 영향)

  • 현도익;문영훈;조종래
    • Transactions of Materials Processing
    • /
    • v.12 no.5
    • /
    • pp.487-492
    • /
    • 2003
  • Tension variations with heat treatment in shadow mask for flat braun tubes are investigated in this study. In CRT, landing shift of the electron beam due to thermal deformation of the tension mask made the color purity of screen worse. In order to get the final results of thermal deformation, the tensile force within the mask and the welding processes between the rail and the extended mask have to be analysed sequentially. In this study, the effect of heat treatment is studied in terms of tension variations of shadow mask during its manufacturing process.

A Study on the Tension Control for Catenary′s cable (현수형 가선케이블의 일정 장력유지 제어에 관한 연구)

  • Hong S. I;Yoon J. H
    • Journal of the Institute of Convergence Signal Processing
    • /
    • v.1 no.2
    • /
    • pp.153-159
    • /
    • 2000
  • The cable installed will have catenary's type that is nonlinear and variable time system. Because it has a close relation to the catenary's type to determine command value of tension for the tension control of this cable, we need to study it. The purpose of this study is automated the installation equipment (or a catenary's cable. This study shows control system that the tension of a catenary's cable is keep constant. 'rho control method is adopted the fuzzy control that is robust because the model of a control object is nonlinear and variable time system and feed-forward control to suppress overshoot as a shift begins to move. On the basis of the dynamic modeling of a catenary's cable we compose the control system with adopting fuzzy and feed-forward control has recognized the effectiveness in simulation results.

  • PDF

Thermal Deformation Analysis of Shadow Mask in a Flat TV and Prediction of Electron Beam Landing Shift by FEM (유한요소법에 의한 평면 TV 새도우마스크의 열변형해석 및 전자빔 오착 예측)

  • Kim, Jeong;Park, Soo-Kil;Kang, Beom-Soo
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.26 no.11
    • /
    • pp.2297-2304
    • /
    • 2002
  • Two-dimensional and three-dimensional finite element methods have been used to analyze the deformation behavior of a shadow mask due to thermal and tension load. The shadow mask inside the Braun tube of a TV set has numerous slits through which the electron beams are guided to land on the designed phosphor of red, green or blue. Its thermal deformation therefore causes landing shift of the electron beam and results in decolorization of a screen. For the realistic finite element analysis, the effective thermal conductivity and the effective elastic modulus arc calculated, and then the shadow mask is modeled as shell without slits. Next a transient thermal analysis of the shadow mask is performed, wherein thermal radiation is a major heat transfer mechanism. Analysis of the resulting thermal deformation is followed, from which the landing shift of the electron beam is obtained. The present finite element scheme may be efficiently used to reduce thermal deformation of a shadow mask and in developing prototypes of a large screen flat TV.

A Study on the Chamical and Physical Characteristics of Ultrasonic-Energy-Added Diesel Fuel (초음파 에너지 부가 지젤연료의 화학적, 물리적 특성에 관한 연구)

  • 최두석;윤면근;류정인
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.4 no.3
    • /
    • pp.147-155
    • /
    • 1996
  • This study investigated the characteristics of ultrasonic-energy-added diesel fuel. We compared the characteristics used H-NMR spectrum, FT-IR spectrum, viscosity and surface tension between conventional diesel fuel and ultrasonic-energy-added diesel fuel. The result are obtained as follow : We knew that ultrasonic energy result to reduce BI and weaken viscosity and surface tension. Also, the ultrasonic energy caused to reduce aromatics Ha and increase Alkanes Hγ. The effect of ultrasonic-energy-added dieselfuel was principally caused by change of chemical structures and a physical characteristics.

  • PDF

Studies on the Mackerel Purse Seine Operating in the Sea Area of Cheju Island - 2 . Model Experiment ob the Deformation of Net in Two Layer Current (제주도 주변 해역 고등어 포착망의 연구 - 2 . 이중조에 있어서 망의 변형에 관한 모형실험 -)

  • 박정식
    • Journal of the Korean Society of Fisheries and Ocean Technology
    • /
    • v.22 no.4
    • /
    • pp.32-40
    • /
    • 1986
  • A model experiment of purse seine by the circulating water tank was carried out on the changes of net shape and the tension of purseline under operation in two layer current. In the circular tank, the two layer current was made by cutting off the current of upper layer and producing the bottom current by the equipment shown in Fig. 1. The model experiment of purse sein was made on a reduced scale 1 :400, and the experiment was carried out according to the Tauti's model law. When the bottom current of O. 5 knot flows to lower part of three-eighths of net, following results are derived. The depth of sinkerline reached only about 80% of that of no current set. The horizontal shift of sinker line caused by the bottom current is maximized in tight set. The enclosed area by the floatIine immediately after the completion of set net is 61. 5% in tight set, 50. 0 % in loose set and 54. 1 % in lateral set of those in the case of no current. In the first half period of pursing, the tension of the purseline is enhenced by the bottom current and the pattern of increasing is irregular in the tension curves.

  • PDF

Shear Deformation based on the Biaxial Tension-Compression Theory in Prestressed Concrete Members applied by Axial Loading (이축인장압축장이론에 기반한 PSC보의 전단변형)

  • Jeong, Jae-Pyong;Kim, Dae-Joong;Mo, Gui-Suk;Kim, Woo
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 2006.11a
    • /
    • pp.281-284
    • /
    • 2006
  • ASCE-ACI Committee 426 and 445, on Shear and Torsion, well noted in their report that recent research work regarding shear and torsion had been devoted primarily to members. But it was not logical approach of PSC members applied by axial force based on the shear deformation in web element. And it was not included that the effect of axial is to shift the shear strain(or crack width) in the web element versus the applied shear curve up or down by the amount by which the biaxial tension-compression state varies. The shear strength also increases or decreases, so that the change in shear strain at service load due to the presence of axial load is to some extent changed. Generally, in corresponding beams the shear strain at service load is less in the beam subject to axial compression and greater in the beam subject to axial tension, than in the beam without axial load. In particular, however, no research were available on the shear deformation in shear of PSC members with web reinforcement, subject to axial force in addition to shear and bending. Therefore, this study was basically performed to develop the program for the calculation of the shear deformation based on the shear effect of axial force in prestressed concrete members.

  • PDF

Effect of Curvature Dependency of Surface Tension on the Result of Pore-Volume Distribution Analysis (동공부피 분포의 계산결과에 미치는 표면장력의 곡률 의존도 효과)

  • Cho Chang-Hyun;Ahn Woon-Sun;Chang Seihun
    • Journal of the Korean Chemical Society
    • /
    • v.16 no.6
    • /
    • pp.341-348
    • /
    • 1972
  • The significance of the curvature dependency correction of surface tension is studied in calculating the pore volume distribution of porous adsorbent from nitrogen adsorption isotherm. That is, Kelvin radii are calculated with curvature dependent surface tension values calculated by Chang et al, and then with these Kelvin radii, pore volume distributions of three porous adsorbents, silica alumina (steam deactivated), silica gel (Davidson 59), and silica gel (Mallinc-krodt Standard Luminescent), are calculated. The results are compared with those obtained by the previous method in which surface tension is taken as constant and also with the others. obtained by the modelless method proposed by Brunauer et al. The maximum point of the distribution curve shift to the larger pore radius, when the curvature dependency is considered. Furthermore, the relative pressure at which capillary condensation commences is by far the lower than that accepted previously. This effect becomes significant as the pore radius approaches to the micropore range.

  • PDF

Intelligent bolt-jointed system integrating piezoelectric sensors with shape memory alloys

  • Park, Jong Keun;Park, Seunghee
    • Smart Structures and Systems
    • /
    • v.17 no.1
    • /
    • pp.135-147
    • /
    • 2016
  • This paper describes a smart structural system, which uses smart materials for real-time monitoring and active control of bolted-joints in steel structures. The goal of this research is to reduce the possibility of failure and the cost of maintenance of steel structures such as bridges, electricity pylons, steel lattice towers and so on. The concept of the smart structural system combines impedance based health monitoring techniques with a shape memory alloy (SMA) washer to restore the tension of the loosened bolt. The impedance-based structural health monitoring (SHM) techniques were used to detect loosened bolts in bolted-joints. By comparing electrical impedance signatures measured from a potentially damage structure with baseline data obtained from the pristine structure, the bolt loosening damage could be detected. An outlier analysis, using generalized extreme value (GEV) distribution, providing optimal decision boundaries, has been carried out for more systematic damage detection. Once the loosening damage was detected in the bolted joint, the external heater, which was bonded to the SMA washer, actuated the washer. Then, the heated SMA washer expanded axially and adjusted the bolt tension to restore the lost torque. Additionally, temperature variation due to the heater was compensated by applying the effective frequency shift (EFS) algorithm to improve the performance of the diagnostic results. An experimental study was conducted by integrating the piezoelectric material based structural health monitoring and the SMA-based active control function on a bolted joint, after which the performance of the smart 'self-monitoring and self-healing bolted joint system' was demonstrated.