• Title/Summary/Keyword: support diaphragm

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Load Characteristics and Sensitivity Analysis for an Automotive Clutch Diaphragm Spring (자동차 클러치 다이어프램 스프링 하중 특성 및 민감도 해석)

  • Lee, Byoung-Soo
    • Transactions of the Korean Society of Automotive Engineers
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    • v.14 no.1
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    • pp.54-59
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    • 2006
  • An analytical solution for deflection-load characteristics of a conical disk spring used especially in the automotive manual transmission clutch applications is proposed in order to take into account the effects of friction and large deformation. The conical disk spring, or the diaphragm spring, has a hinge support, an application point of release load at the tip of the fingers and an application point of clamp load near but inside the outer perimeter of the conical disk spring. The friction coefficient is assumed to be a constant regardless of the speed of deflection and the magnitude of loads. Comparison with experimental shows a good agreement with the analytical prediction. Also, the sensitivity of the clamp load due to variations in the geometrical parameters of the conical disk spring is calculated and discussed.

Open Transthoracic Plication of the Diaphragm for Unilateral Diaphragmatic Eventration in Infants and Children

  • Alshorbagy, Ashraf;Mubarak, Yasser
    • Journal of Chest Surgery
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    • v.48 no.5
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    • pp.307-310
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    • 2015
  • Background: To evaluate our experience of early surgical plication for diaphragmatic eventration (DE) in infancy and childhood. Methods: This study evaluated infants and children with symptomatic DE who underwent plication through an open transthoracic approach in our childhood development department between January 2005 and December 2012. Surgical plication was performed in several rows using polypropylene U-stitches with Teflon pledgets. Results: The study included 12 infants and children (7 boys and 5 girls) with symptomatic DE (9 congenital and 3 acquired). Reported symptoms included respiratory distress (91.7%), wheezing (75%), cough (66.7%), and recurrent pneumonia (50%). Preoperative mechanical ventilatory support was required in 41.7% of the patients. The mean length of hospital stay was $6.3{\pm}2.5days$. The mean follow-up period was $24.3{\pm}14.5months$. Preoperative symptoms were immediately relieved after surgery in 83.3% of patients and persisted in 16.7% of patients one year after surgery. All patients survived to the end of the two-year follow-up and none had recurrence of DE. Conclusion: Early diagnosis and surgical plication of the diaphragm for symptomatic congenital or acquired diaphragmatic eventration offers a good clinical outcome with no recurrence.

Top-Down Method of Deep Basement Construction in Urban Area : a Comparison of Numerical Analysis and Field observation Data (도심지 지하굴착에 적용된 Top-Down 공법의 수치해석과 실측비교)

  • 김학문
    • Proceedings of the Korean Geotechical Society Conference
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    • 1991.10a
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    • pp.312-331
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    • 1991
  • Top-down Method of basement construction technique has been applied for building of the deep basement car park the close proximity of priceless historic buildings in LONDON. Numerical analysis for the prediction of ground movement of the surrounding buildings was performed in order to compare the field data at the various stages of excavation and support. The predicted results from the elasto-plastic analytical method were compared with the observed data and the agreement is very satisfactory. It may be concluded that the system of diaphragm wall supported by the permanent base slabs (Top-Down Method) was proved to be the most effective technique in terms of reducing any critical damage to the surrounding buildings.

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Design of Blank Support Structure for Large and Curved Thick Plate Forming (대면적 후곡판 성형을 위한 블랭크 지지구조 설계)

  • Kwak, B.S.;Yoon, M.J.;Jeon, J.Y.;Kang, B.S.;Ku, T.W.
    • Transactions of Materials Processing
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    • v.27 no.1
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    • pp.18-27
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    • 2018
  • As one of the functional metal parts in steam turbine diaphragm assembly, the hollow-partitioned turbine nozzle (stator) has large and thick geometries, as well as an asymmetric configuration. Therefore it is hard to support a metal blank in the die cavity. To ease this situation and control posture and position of metal blank (workpiece), a blank support structure is newly introduced. The blank support structure is basically composed of enlarged arms from the blank, guide pins and linear bearings. It can help to control the intermediate blank without a critical sliding phenomenon. The operation mechanism of this blank support structure, during thick plate forming for the hollow-partitioned turbine nozzle stator, is first evaluated. A series of FEM-based numerical simulations, with respect to the width of the guide arm as geometric design parameters, are carried out to investigate its applicable range. As the results, it is observed the blank support structure for this thick plate forming can guide the workpiece to have stable posture during the plate forming process.

A Study on Pylon Cable Anchor System in Cable-Stayed Railway Bridge (철도용 사장교의 주탑 케이블 정착부에 관한 연구)

  • Han, Sung-Gwan;Gong, Byung-Seung
    • Proceedings of the KSR Conference
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    • 2006.11b
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    • pp.565-580
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    • 2006
  • Set in constant increase and period current of lively technical development of railroad use and construction of cable stayed bridge railway bridge, one of bridge form of most suitable that think side police officer and the material enemy of bridge that use long rail, is increasing laying stress on the foreign countries. Main tower fixing department of this cable stayed bridge is consisted of main tower flange that support bearing plate, bay ring plate bearing plate, support end rib and diaphragm etc, as stress transmission mechanic that tensility of cable socket into normal force of main tower, and is used this time. These structural elements is very complex the structure and direction of load delivered from socket specially calbe particularly be different, and need FEM analysis that use Thick Shell element for suitable arrangement of mutual stress flowing grasping and absence that follow hereupon because all of the each support plate angle that suport this differ.

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Analysis of the Steel Deck Bridges using the Finite Strip Method (유한대판법을 사용한 강상판 교량의 해석)

  • 최창근;홍현석
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1998.04a
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    • pp.77-84
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    • 1998
  • The finite strip method is presented for the analysis of steel deck bridges. Like the Pelikan-Esslinger design method for the steel deck bridges, steel deck is treated as an equivalent orthotropic plate. In the presented method, the deck is discretised by finite strips in the longitudinal direction and the effect of main girder or floor beam deflection can also be accounted for. In this method, the terms of harmonic series at elastically support such as transverse floor or diaphragm in steel deck become coupled. Solutions of this method are compared with other available analytical and numerical solution, and good agreement is observed.

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Seismic Behavior of H shaped Beam to Square Column Connection with Outer Diaphragm Using Field Welding (외측 다이아프램을 사용한 현장 용접형 각형강관기둥-H형강보 접합부의 이력거동)

  • Seo, Seong Yeon;Jung, Jin Ahn;Choi, Sung Mo;Kim, Sung Young
    • Journal of Korean Society of Steel Construction
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    • v.17 no.4 s.77
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    • pp.459-467
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    • 2005
  • This study focuses on the development of a new method of H-shaped beam-to-square column connection with an outer diaphragm and a field welding. The specific type of beam-to-column connection with an external stiffener, using field welding, is proposed. The structural behavior of this connection was examined experimentally. Two loading type tests were conducted under the experimental parameters given as details. First described was the symmetrical loading test, which supported both ends or a beam simply and applied a load from the column to the pend (What does this mean?) to investigate a fundamental characteristic of this connection. Further described was the anti-symmetrical loading test, which carried out simple support of the column'stop end and the column base, and applied a load from both ends of a beam to investigate the structural performance of this connection. From the results, it is clear that the external- stiffener-type connection proposed in this paper is the reliable connection method.

Lateral Load Distribution for Prestressed Concrete Girder Bridge (PSC 거더교의 하중횡분배에 관한 연구)

  • Park, Moon-Ho;Park, Jung- Hwal;Kim, Jin- Kyu
    • Journal of the Korean Society of Industry Convergence
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    • v.4 no.2
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    • pp.157-166
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    • 2001
  • The purpose of this study is to examine the accuracy of the code provisions on lateral load distribution factors of prestressed concrete girder bridges. Most designers in Korea use the lever method or lateral load distribution formula in the existing design codes. However, the methods do not account for the effect of bridge skew or direction of diaphragm. Therefore, this study analysed the prestressed concrete girder bridge with grillage model for various girder spacings, directions of diaphragms, span lengths, and skews, and compared the results with those of existing design code. It has been found that lateral load distribution factors were proportional to the girder spacing while they were not significantly affected by the change of span length, direction of diaphragm, and skew. For bending moments, lateral load distribution factors from the grillage analysis were 60%~68% of those from Korean bridge design code. Therefore, the code provisions result in very conservative design. For support reactions, however, lateral load distribution factors from the grillage analysis were slightly greater than those from Korean bridge design code. Therefore, the capacity of bearings of the bridge with a large skew should be determined by grillage analysis.

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A Compatibility Study on Blank Support Structure for Large and Curved Thick Plate Forming (대곡면 후곡판 성형을 위한 블랭크 지지구조의 적합성 연구)

  • Lim, M.R.;Kwak, B.S.;Kang, B.S.;Ku, T.W.
    • Transactions of Materials Processing
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    • v.28 no.6
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    • pp.335-346
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    • 2019
  • Thick plate forming is presented to manufacture a large and curved member of steam turbine diaphragm. Due to three-dimensional asymmetry of target geometry, it is hard to consistently keep the blank position in die cavity between forming punch and die. In order to relieve the position instability of the blank during the thick plate forming, a blank support structure is proposed to be composed of guide pins and linear bearing, and blank guide arm enlarged from both longitudinal ends of the thick blank. In this study, parametric investigations with regard to the geometric position and width of the blank guide arm are carried out. As main geometric parameters, 2 positions such as maximum curvature region and minimum one on a curved cross-section profile of the target shape are selected, and 14 widths of the blank guide arm are considered. Using 28 variable combinations, three-dimensional numerical simulations are performed to predict the appropriate range of the process parameters. The compatibility and validity of the blank support structure with the blank guide arm for the thick plate forming is verified through the thick plate forming experiments.

Finite element modeling of slab-on-beam concrete bridge superstructures

  • Patrick, Michael D.;Huo, X. Sharon
    • Computers and Concrete
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    • v.1 no.3
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    • pp.355-369
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    • 2004
  • This paper presents a study of four finite element techniques that can be used to model slabon-beam highway bridges. The feasibility and correctness of each modeling technique are examined by applying them to a prestressed concrete I-beam bridge and a prestressed concrete box-beam bridge. Other issues related to bridge modeling such as torsional constant, support conditions, and quality control check are studied in detail and discussed in the paper. It is found that, under truck loading, the bending stress distribution in a beam section depends on the modeling technique being utilized. It is observed that the behavior of the bridge superstructure can be better represented when accounting for composite behavior between the supporting beams and slab.