• Title/Summary/Keyword: Diaphragm's Shape

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Predicting the stiffness of shear diaphragm panels composed of bridge metal deck forms

  • Egilmez, Oguz O.
    • Steel and Composite Structures
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    • v.24 no.2
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    • pp.213-226
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    • 2017
  • The behavior of building industry metal sheeting under shear forces has been extensively studied and equations have been developed to predict its shear stiffness. Building design engineers can make use of these equations to design a metal deck form bracing system. Bridge metal deck forms differ from building industry forms by both shape and connection detail. These two factors have implications for using these equations to predict the shear stiffness of deck form systems used in the bridge industry. The conventional eccentric connection of bridge metal deck forms reduces their shear stiffness dramatically. However, recent studies have shown that a simple modification to the connection detail can significantly increase the shear stiffness of bridge metal deck form panels. To the best of the author's knowledge currently there is not a design aid that can be used by bridge engineers to estimate the stiffness of bridge metal deck forms. Therefore, bridge engineers rely on previous test results to predict the stiffness of bridge metal deck forms in bracing applications. In an effort to provide a design aid for bridge design engineers to rely on bridge metal deck forms as a bracing source during construction, cantilever shear frame test results of bridge metal deck forms with and without edge stiffened panels have been compared with the SDI Diaphragm Design Manual and ECCS Diaphragm Stressed Skin Design Manual stiffness expressions used for building industry deck forms. The bridge metal deck form systems utilized in the tests consisted of sheets with thicknesses of 0.75 mm to 1.90 mm, heights of 50 mm to 75 mm and lengths of up to 2.7 m; which are representative of bridge metal deck forms frequently employed in steel bridge constructions. The results indicate that expressions provided in these manuals to predict the shear stiffness of building metal deck form panels can be used to estimate the shear stiffness of bridge metal deck form bracing systems with certain limitations. The SDI Diaphragm Design Manual expressions result in reasonable estimates for sheet thicknesses of 0.75 mm, 0.91 mm, and 1.21 mm and underestimate the shear stiffness of 1.52 and 1.90 mm thick bridge metal deck forms. Whereas, the ECCS Diaphragm Stressed Skin Design Manual expressions significantly underestimate the shear stiffness of bridge metal deck form systems for above mentioned deck thicknesses.

Analysis of Monitoring Results and Back Analysis for Rigid Diaphragm Wall Supported by Ground Anchor (지반앵커로 지지된 강성 지하연속벽체의 상세계측 결과분석 및 역해석 평가)

  • Lee, Jong-Sung;Hwang, Eui-Suk;Cho, Sung-Hwan;Lee, Jun-Hwan
    • Journal of the Korean Geotechnical Society
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    • v.25 no.5
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    • pp.39-46
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    • 2009
  • In this study, behavior of a rigid continuous wall, earth pressure distribution with construction stage, and axial force of earth anchors were evaluated based on field monitoring data and numerical analysis results. For this purpose, a construction site excavated using the diaphragm wall was selected and full instrumentation system was introduced. From monitoring results, it was found that the values of horizontal displacement of the wall measured from the inclinometers, which were installed within the diaphragm wall were similar to analytical value. The earth pressure increased with excavation progress due to jacking force of the ground anchors installed in previous excavation stages. When the excavation depth reached 60% of the final depth, observed earth pressure distribution was similar to that estimated from Peck's apparent earth pressure distribution. When the excavation depth was around 90% of the final depth, values of observed earth pressure showed middle values between those of Peck's and Tschebotarioffs apparent earth pressures. It was also observed that, when excavation depth is deep, values of the earth pressures from the rigid wall were similar to those estimated from conventional earth pressure distribution shape proposed for flexible walls.

Structural Analysis for Silk Hat type of the Harmonic Drive for Precision Robot (정밀 로봇용 하모닉 드라이브의 실크 햇 형상에 따른 구조해석)

  • Nam, W.K.;Ham, S.H.;Oh, S.H.
    • Journal of Power System Engineering
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    • v.15 no.5
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    • pp.61-66
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    • 2011
  • Recently, the speed reducer which is applied to robot has conducted a steady development on developments in the field of robotics. Among them, Harmonic drive is a high-stiffness, precision-controlled speed reducer and has high precision, compact, light in weight and high-reduction-ratio characteristics. The feature of flexspline of Harmonic Drive are two types. One is Cup type, the other is Silk Hat type. Silk Hat type is used in case of lighter and more compact in spatial because Silk Hat Type is hollow. According to the shape of silk hat, diaphragm is fractured because stress is concentrated. In this paper, the various shapes of silk hat are suggested to improve the durability of silk hat. And in the case of each shape, a study on stress and deformation using the FEM tool was carried out on flexspline.

The Effect of Secondary Members on the Behavior of Steel-Concrete Composite Two-Girder Railway Bridges (2거더 강-콘크리트 합성형 철도교의 거동에 대한 2차부재의 영향 평가)

  • Bae Doo-byong;Cho Joon-hee
    • Journal of the Korean Society for Railway
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    • v.8 no.1
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    • pp.41-50
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    • 2005
  • Steel -Concrete Composite two girder railway bridges applying high performance steel with extra thick plate have economic and aesthetic advantages due to the simplification of manufacturing and construction process. However, steel bridges are seldom adopted in domestic railway bridge, since steel bridges are not efficient as R.C bridges considering dynamic characteristics and noise, etc. While highway bridges do not have lower horizontal bracing and larger interval of diaphragm cross beam, railway bridges install lower horizontal bracings to control the torsion due to heavy eccentrical line load. Accurate finite element analysis were performed with the parameters of existence of bracing and bracing shape, with the cross beam interval and stiffness, etc. To find out the effects of secondary members such as horizontal bracings and diaphragms, static md dynamic analysis have been performed by using finite element method. In this study, few member plate-girder bridges are analyzed with variable span lengths to examine the dynamic behavior and limits of damping. And though lateral bracings are members against torsion, but lateral bracing's absence is no big problem. Time history analysis using mode superposition method makes proof of this result.

Schistosomus reflexus in Korean native calf (한우 송아지의 반전성열체)

  • Kim, Chong-sup;Huh, Chan-kwen;Lee, Jong-hwan;Lee, Jong-han
    • Korean Journal of Veterinary Research
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    • v.36 no.2
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    • pp.289-296
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    • 1996
  • A case of schistosomus reflexes in Korean native female calf was observed macroscopically and radiographically. The results were summarized as follows. 1. The abdominal visceral organs were exposed. 2. The vertebral column bent laterally to the left, and the sacrum approached to the cranium by reflected caudal lumber vertebrae, presenting S-shaped lateral twisting of the vertebrae. 3. The right ribs reflected laterally and dorso-cranially from the 7th rib to 13th rib. The left ribs bent caudally from 8th rib to 13th rib. 4. The length of rudimentary 6th right rib was one half of normal size and the 7th right rib was one third. 5. The sternum was bifid split from the fourth sternebra through the xyphoid cartilage. 6. The diaphragm was intact and thoracic cavity was reduced in size. The lung and heart severely deformed in shape and size. 7. The liver markedly deformed in shape and thickness. 8. The pelvic cavity was reduced in size by compression laterally to the left. 9. The uterus horn, ovary, urinary bladder, and urethra were severely deformed in the shape and position.

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Surgical Treatment of the Morgagni Hernia: report of one case (Morgagni 탈장증 수술 1예)

  • 김송명
    • Journal of Chest Surgery
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    • v.12 no.4
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    • pp.429-433
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    • 1979
  • Morgagni hernia is a rare condition of the congenital diaphragmatic hernia which Is located at the anteromedial portion of the diaphragm, and is located immediately posterior to the sternum. Its cause is considered by embryologic defect and the abdominal organs are passed through a defect. The incidence is predirected women over 50 years old. Its synonym is hernia of subcostosternal, retrosternal, parasternal, rectocostoxiphoid, anterior diaphragmatic or Larrey`s. This report presents a symptomatic Morgagni hernia of ten months old male child on whom the diagnosis was established and was operated at the Busan Gospel Hospital. This patient was admitted with the chief complaints of mild cyanosis, frequent upper respiratory infections and protrusion of the right lower anterior chest. Herniorrhaphy was performed through the upper abdominal midline incision, hernial contents of the omentum and the colon, and sac as noticed from the Larrey`s space measuring 4 x 2 cm. in diameter and oval in shape. Interrupted sutures without difficulty repaired the defect. The cyanosis was disappeared and the patient had uneventful course of post-operative period. The patient was discharged at 7th. postoperative day. This case presentation with a brief review of literatures is given.

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A Study on Seismic Performance for CFT Square Column-to-Beam Connections Reinforced with Asymmetric Lower Diaphragms (이형 하부다이아프램으로 보강된 각형 CFT 기둥-보 접합부의 내진성능에 관한 연구)

  • Choi, Sung Mo;Yun, Yeo Sang;Kim, Yo Suk;Kim, Jin Ho
    • Journal of Korean Society of Steel Construction
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    • v.15 no.5 s.66
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    • pp.579-589
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    • 2003
  • Most beam-to-column connections are symmetrically reinforced because of the reverse action caused by earthquakes. However, in weak-earthquake regions like Korea, asymmetrically reinforced connections could be used. In particular, the connections between concrete-filled tube (CFT) column and H-shape beam could be applied using a simplified lower diaphragm. The tensile capacity or Combined Cross Diaphragm for upper reinforcing was tested using a simple tension test. Four types for lower reinforcing combined Cross, none, horizontal T-bar, and vertical plate were tested using the ANSI/AISC SSPEC 2002 loading program. Horizontal T-bar and stud bolts in vertical flat, bar transmit tensile stress from the beam's bottom flange to filled concrete. All test specimens satisfied 0.01 radian inelastic rotational requirement in ordinary moment frame of AISC seismic provision. According to the results of the parametric studies simplified lower diaphragms demonstrated outstanding strength, stiffness, and plastic deformation capacity which could lead to more sufficient seismic performance in the field.

Zigbee Based Wireless Respiration Monitor System (지그비 통신 기반의 근거리 무선 호흡모니터 시스템)

  • Lee, In-Kwang;Kim, Seong-Sik;Jang, Jong-Chan;Kim, Koon-Jin;Kim, Kyung-Ah;Lee, Tae-Soo;Cha, Eun-Jong
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.1
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    • pp.142-147
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    • 2008
  • Abdominal circumference changes due to breathing by the respiratory muscle activity such as diaphragm, which would partially represent the lung volume variation. The present study introduced conductive rubber molded in a cord shape incorporated with a patient's pants. The conductive rubber cord operated as a displacement transducer to measure the lung or abdominal volume changes. Signal extraction circuitry was developed to obtain the volume and its derivative(or the flow) signals followed by wireless transmission based on the Zigbee communication protocol in a size of $65mm{\times}105mm$ easily put in pocket. Breathing frequency was accurately evaluated and breath pattern analysis seemed feasible, since respiratory behaviours such as maximal inspiration and cough were well identified. Remote wireless receiver module also enabled to monitor both volume and flow signals during resting breathing on a PC terminal.

Surgical Removal of the Lung Lobe Metal Foreign Body in a Dog

  • Hwang, Yawon;Kang, Jihoun;Chang, Dongwoo;Kim, Gonhyung
    • Journal of Veterinary Clinics
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    • v.34 no.2
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    • pp.108-111
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    • 2017
  • A 4-year-old, weighing 7.6 kg, castrated male, Pug presented with ingestion of gastric cavity foreign body. Physical examination revealed panting, retching and hyper-salivation. Blood chemistry and complete blood cell count were normal, but hypophosphatemia was observed. An abdominal radiograph revealed the foreign body (FB), round shape and 2 cm length, at the pyloric region of stomach. A thoracic radiograph revealed an incidental metal FB, 3.5 cm length, at the cranial portion of the diaphragm. An upper gastrointestinal endoscopy was performed to remove the FB in the stomach and then a peach-pit was removed. However the metal FB was not found in the esophagus therefore a lateral thoracotomy was performed. A right lateral thoracotomy through the $7^{th}$ intercostal space was accomplished to expose the right caudal lung lobe. After open the thoracic cavity, foreign body was not observed by gross evaluation and caudal lung lobe was attached to the diaphragm. The FB was identified inside the lung lobe and surrounded by granulation tissue. The metal FB (sewing needle) was removed with blunt dissection and incised lung lobe was sutured using absorbable suture material PDS 4-0 with interrupted suture. A thoracotomy tube was inserted into the thoracic cavity during surgery. Patient's respiration became stable after surgery. A chest tube was removed 3 days after surgery. No complications were noted and the dog was discharged 4 days after surgery. In small animal, foreign body ingestion is a common reason for emergency. After ingestion of the FB, perforation through the esophagus and migration to inside the lung lobe is not common in small animals. In this case, thoracic metal FB was identified incidentally and removal of a thoracic FB with thoracotomy was performed successfully.

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.