• Title, Summary, Keyword: Dome Part

Search Result 69, Processing Time 0.045 seconds

Forming of Dome and Inlet Parts of a High Pressure CNG Vessel by the Hot Spinning Process (열간 스피닝 공정을 통한 CNG 고압용기의 돔 및 입구 부 성형)

  • Lee, Kwang O;Park, Gun Young;Kwak, Hyo Seo;Kim, Chul
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.40 no.10
    • /
    • pp.887-894
    • /
    • 2016
  • The CNG pressure vessel is manufactured by a deep drawing and ironing (D.D.I) process for forming cylinder parts, followed by a spinning process for formation of the dome part. However, studies on the buckling phenomenon of the dome part and formation of the inlet part have not been performed yet, and the CNG pressure vessel is produced by the experience of the field engineers and the trial and error method. In this study, buckling phenomenon during the spinning process was predicted by comparing critical buckling loads obtained through theoretical analysis with axial loads from the FEA, and a method for preventing buckling of the dome part was proposed by employing commercial software (Forge NxT 1.0.2). Also, to form the inlet part, forming loads of the roller at contact point between the roller and the dome part were analyzed according to radii of the dome part, and the inlet part was formed by controlling the radius of the dome part.

Thermal Stress Analysis of Ramjet Dome Port Part (램제트 돔 포트 부의 열응력 해석)

  • Kim, Seung-Joong;Choi, Young-Jin;Lee, Young-Shin;Kim, Jae-Hoon;Koo, Song-Hoe
    • Proceedings of the KSME Conference
    • /
    • /
    • pp.716-721
    • /
    • 2004
  • In this study, dome port bringing up for discussion where the ramjet occurs in flying it presents the tendency of distribution of thermal contour due to temperature and pressure. It is assumed that the material of ramjet is steel for the ease of result analysis. It applied matrial property which it follows by temperature and input boundary condition that changing temperature and pressure on each region by time difference for transient analysis. Thermal analysis region is decided until dome port part is separated and operate analysis in 0.5 second. Finally we draw tendency of thermal contour in ramjet dome port part by temperature and pressure.

  • PDF

Optimal Design of the Fuel Storage Vessel of CNG Automobile by Considering Structural Efficiency (구조 효율을 고려한 CNG 자동차 연료저장용기의 최적설계)

  • Kim, Ho-Yoon;Bae, Won-Byong;Jang, Young-Jun;Kim, Chul
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.32 no.6
    • /
    • pp.465-473
    • /
    • 2008
  • Type II compressed natural gas(CNG) storage vessels for automobiles have been acknowledged for their excellence and have recently become established in local regions. Their supply is not only to automakers in Korea such as Hyundai Motors but they are being increasingly exported. Although the available products have undergone safety evaluations and are certified by an authorized institution they are still short of the optimal design that is possible for such storage vessels. This research investigates the shape and thickness of the dome with the aim of optimizing the type II CNG storage vessels by using a finite element analysis technique. CNG storage vessels can be largely divided into 3 parts namely, the hear part, the cylinder part and the dome part. The head part is designed by means of a hot spinning process and this method is safer than that used in the design of the dome part even though its shape is similar. The thickness of the liners and reinforcing materials was optimized based on the requirements of the cylinder and dome parts. In addition, the shape of the dome, which is most suitable for Type II CNG storage vessels, is proposed by a process of review and analysis of various existing shape, and then conducting a structural stability evaluation to ensure the optimal design plan.

Composite Pressure Vessel for Natural Gas Vehicle by Filament Winding (필라멘트 와인딩 공정에 의한 천연가스 차량용 복합재료 압력용기)

  • 김병선;김병하;김진봉
    • Composites Research
    • /
    • v.17 no.5
    • /
    • pp.1-6
    • /
    • 2004
  • Composite pressure vessels with HDPE (high density polyethlyne) liner with metal boss at each end were developed by Filament Winding Process. The vessel is composed of a dome-shaped part at each end and a cylinder-shaped part at the middle of the vessel. The environmental tests carried out for possible vessel materials such as High Density Polyethlyn (HDPE), resins and reinforcing fibers up to a year showed no significant damages. The boss was designed to minimize the gas leak which was verified by FEM analysis. Most ideal fiber tension was obtained by experimental method and the fiber volume fraction, $\textrm{V}_{f}$, obtained by image analyzer were 55.4 % in cylinder and 55.6 % in dome parts, respectively. Winding pattern is programmed to control the composite thickness in the dome areas such that the failure of the vessel may occur in the cylinder. During the cure, the vessel was rotated and a constant internal pressure of 0.62 bar was applied. From this, the vessel's burst pressure is improved by 28 %. The burst and fatigue tests for under-wound and fully wound vessel showed satisfactory results.

A Study on the Fracture Characteristics of Ceramics Using Compressed Shock Wave (압축 충격파를 이용한 세라믹의 파괴특성에 관한 연구)

  • Hwang, Kwon-Tae;Kim, Jae-Hoon;Lee, Young-Shin;Park, Jong-Ho;Song, Kee-Hyeuk;Yoon, Su-Jin
    • Proceedings of the KSME Conference
    • /
    • /
    • pp.338-343
    • /
    • 2008
  • Fracture characteristics of plates and dome shapes for machinable glass ceramics using compressed shock wave. Machinable glass ceramics have been considered as a promising candidate material for the dome port cover of air breathing engine. This part of the air breathing engine has an important role separating solid and liquid fuel, and needs the frangible characteristics whereby the fracture of a part should not affect the internal components of combustion. The objective of this study are to evaluate the fracture pressure and phenomena of separated membrane using a shock tunnel. The experimental apparatus consists of driver, a driven section and a dump tank. The used material is machinable glass ceramic from Corning company. Specimens are used 3, 4.5 and 6mm thickness with plates and dome shapes. It is expected that the results obtained from this study can be used in the basic data for the dome port cover design of an air breathing engine.

  • PDF

Experiment and Rigid Element Analysis of R.C. Spherical Dome (철근콘크리트 구형돔의 실험 밀 강체요소해석)

  • 박강근
    • Proceedings of the Computational Structural Engineering Institute Conference
    • /
    • /
    • pp.295-302
    • /
    • 1999
  • This paper is the experimental and analytic of reinforced concrete hemisphere dome under vertical load. It is described that when the reinforced concrete hemispherical dome supported on cylindrical wall is loaded vertically, how the opening part of dome will behave mechanically The experimental and analytic model is a Hemispherical dome with opening and the meridian angle of opening is 76$^{\circ}$at the center of sphere under concentrated load around the opening, but this is reinforced by a ring is sufficient stiffness. The diagrams of crack development are represented to understand the behavior of the reinforced concrete hemispherical dome. The method of crack analysis will be applied the rigid element spring model. The rigid element spring model is a new discrete element analysis, each divided element is assumed by rigid elements without deformation which is interconnected with elasto-plastic spring system.

  • PDF

Study on the Dynamic Instability of Star-Dome Structures (스타돔의 동적 불안정 현상에 관한 연구)

  • Han, Sang-Eul;Hou, Xiao-Wu
    • Proceedings of the Computational Structural Engineering Institute Conference
    • /
    • /
    • pp.72-77
    • /
    • 2008
  • Stability is a very important part which we must consider in structural design. In this paper, we take advantage of finite element method, and study about parametrical instability of star-dome structures, which is subjected to harmonically pulsating load. When calculating stiffness matrix, we consider elastic stiffness and geometrical stiffness simultaneously. In equation of motion, we represent displacements and accelerations by trigonometric series expansions, and then obtain Hill's infinite determinants. After first order approximation, we can get first and second order dynamic instability region finally.

  • PDF

A Study on the Structural Behavior of Cable Domes (케이블 돔의 구조적 거동 특성에 관한 연구)

  • 한상을;윤종현;이승훈;진영상;황보석
    • Proceedings of the Computational Structural Engineering Institute Conference
    • /
    • /
    • pp.151-158
    • /
    • 2000
  • Cable dome that consists of three component such as cable, strut and fabric membrane has complex structural characteristics. Main structural system of cable dome is cable-strut tensegric system and fabric membrane element is conceived as cladding roof material. One of the important problem of cable dome is to investigate the structural response from external load effect such as snow and wind. When cable dome is subjected to load each structural component has various special structural characteristics. One is that geometrical nonlinearity should be considered because large deformation is occurred from their flexible characteristic. The other is that wrinkling occurs occasionally because cable and membrane elements can not transmit compressive forces. So this paper researches the physical structural response of cable dome structure and the structural behavior when failure occurred at a part of structure.

  • PDF

Dynamic Instability of Lattice-Dome Structures by Lyapunov Concept

  • Han, Sang-Eul;Hou, Xiao-Wu
    • Architectural research
    • /
    • v.10 no.1
    • /
    • pp.25-32
    • /
    • 2008
  • Stability is a very important part which we must consider in structural design. In this paper, we take advantage of finite element method to study parametrical instability of lattice dome structures, which is subjected to harmonically pulsating load. We consider elastic stiffness and geometrical stiffness simultaneously during the calculation of stiffness matrix, and adopt consistent mass matrix to make the solution more correct. In order to obtain instability regions, we represent displacements and accelerations in dynamic equation by trigonometric series expansions, and then obtain Hill's infinite determinants. After first order approximation, we can get first and second order dynamic instability regions eventually. Finally, we take 24-bar star dome and 90-bar lamella dome as examples to investigate dynamic instability phenomena.

A Study on the Dome Plan of S. M. del Fiore Church of F. Brunelleschi (브루넬레스키의 산타 마리아 델 휘오레 교회의 돔계획에 관한 연구)

  • Kim, Seok-Man
    • Journal of architectural history
    • /
    • v.21 no.5
    • /
    • pp.19-32
    • /
    • 2012
  • The purpose of this paper is a study on the dome plan of S. M. del Fiore Church of F. Brunelleschi. The results of study are as follows: 1. The planning of floor, elevation and cross section plan of S. M. del Fiore church is basically planned by each other correlation. In particular, the octangular form of geometrical standard which is formed with altar as the center at the crossing part is important component elements which is decided by not only the dome, but form and size of the drum and floor plan form of the lantern 2. The dome which has been planned by F. Brunelleshi has completed the new dome, preserving gothic thought intended by the church plan after study on architecture of ancient Rome with Pantheon. And the dome which is a main space of church through all aspects of plan, structure, function and construction about the dome is a opportunity in the beginning of Renaissance architecture which is a new epoch and a turning point of architecture on various point of view. 3. The dome which is constructed by F. Brunelleshi has been planned through the innovative solution by the refusal of traditional semicircle form dome, centering use and creation double-shell structure form for the first time in history. And the construction of dome has been solved with the invention of various construction equipments and machineries, the stone rib planned for connection and reinforcement about shells of the octangular form, the support method for reduction the gravity of bricklayers work and the brick work of nock-patterned shape which is masonry construction method of the architecture of ancient Rome.