• Title/Summary/Keyword: bulging

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The Clinical Analysis on 32 Cases of Herniated Lumbar Disc Patients according to Lumbar CT scan. (Lumbar Spine CT 촬영한 요각통 환자 32례의 치료경과 분석)

  • Kim, Jeong-Ho;Lee, Jeong-Hwan;Kim, Young-Il
    • Journal of Pharmacopuncture
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    • v.13 no.2
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    • pp.111-120
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    • 2010
  • Objective: This study is to evaluate the effectiveness of the oriental medicine treatment on lumbar disc herniation. Subjects and Methods : The clinical analysis was done on 32 cases of patients with lumbar disc herniation diagnosed by lumbar CT scan. Patients who admitted In Cheongju Oriental Medicine Hospital from April 2007 to April 2008 were analyzed according to the distribution of sex, age, the period of disease, condition on admission, the symptom on admission, Admission day, the treatment efficacy at discharge day. Results : 1. The forties was the most, the acutest phase the most, the day of 8-14 days the most. 2. Multiple bulging disc in 37.5% of CT scan was the most common, followed by a single HNP was 28.1%. 3. Almost 81 % patients showed effective efficacy under VAS 3 at discharge day. 4. Single bulging and herniated disc were more short admission days than multiple bulging and herniated disc.

Joining of Multi Nodes of a Titanium Bicycle by the Superplastic Hydroforming and Diffusion Bonding Technology (티타늄 자전거의 다중 조인트 접합을 위한 초소성 하이드로포밍과 확산 접합 기술)

  • Yoo, Y.H.;Lee, S.Y.
    • Transactions of Materials Processing
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    • v.28 no.1
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    • pp.15-20
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    • 2019
  • The superplastic forming/diffusion bonding process has been developed to fabricate a core frame structure with joint nodes out of tubes, for the development of a titanium high performance bicycle. The hydroforming process has been applied for bulging of a tube in the superplastic condition before, and during the diffusion bonding process. In this experiment, a commercial Ti-3Al-2.5V tube was selected as raw material for the study. The forming experiment has been performed using a servo-hydraulic press with a capacity of 200 ton. Next, nitrogen gas was used to acquire necessary pressure for the bulging and bonding of the tubes to fabricate the joint nodes. The pertinent processing temperature was $870^{\circ}C$ for the superplastic hydroforming/diffusion bonding (SHF/DB) process, using the Ti-3Al-2.5V tube. The bonding quality and the progress of bulging and diffusion bonding have been observed by the investigation of the joining interfaces at the cross section of the joint structure. The control of the nitrogen pressure throughout the SHF/DB process, was an important factor to avoid any significant defects in the joint structure. The whole progress stage of the diffusion bonding could be observed at a joint interface. A core structure with 5 joint nodes to manufacture a titanium bicycle could be obtained in a SHF/DB process.

Study on the hydro-formability of double layered tube (이중튜브 강관의 액압 성형 특성 연구)

  • Kwon, S.O.;Yi, H.K.;Jang, J.H.;Jeon, D.H.;Moon, Y.H.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2007.05a
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    • pp.306-309
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    • 2007
  • In this study, hydroforming characteristic of the double-layered tube was investigated in the hydroforming process. The double-layered tube can be made outer surface on the stainless steel by only one processing. The free bulging test was performed to analysis optimized pressure and axial feeding amount of the double layered tubes. And the experimental results between stainless/carbon and carbon/carbon double-layered tube were compared with the forming data. Moreover analysis model that can be hydroformability and predictable forming pressure of double-layered tube was presented.

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Analysis of Electromagnetic Forming Using Sequential Electromagnetic-Mechanical Coupled Simulations (순차적 전자기-구조 연성해석을 통한 전자기성형 공정 해석)

  • Kim, J.;Noh, H.G.;Ko, S.J.;Kim, T.J.
    • Transactions of Materials Processing
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    • v.21 no.7
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    • pp.441-446
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    • 2012
  • A sequential coupled field analysis of electromagnetic free bulging was performed by using FEM. A 2D axi-symmetric electromagnetic model based on the magnetic vector potential is proposed for the calculation of magnetic field and Lorentz's forces. The Newmark integration method is used to calculate the transient dynamic plastic deformation of sheet during free bulging. In the finite element model, the effect of sheet deformation on the electromagnetic field analysis is taken into consideration. In order to confirm the sequential electromagnetic-mechanical coupling analysis, an experiment with an electromagnetic forming apparatus was conducted. The results showed that the final bulge height of the sheet predicted from the proposed method is in good agreement with experimentally measured height.

Effects of Process Parameters owl the Tube Hydroformability (하이드로포밍 성형성에 미치는 공정인자 영향도 해석)

  • 김봉준;김정운;문영훈
    • Transactions of Materials Processing
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    • v.11 no.1
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    • pp.54-60
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    • 2002
  • The purpose of the present paper is to investigate the effect of Process parameters such as internal pressure, amount of axial feeding, and frictional condition between the die and the material on the tube hydro-formability. For carbon steel tubes(STKM 12A, STBH 410 and SPS 290), simple bulging, circular bulging and Tee-fitting tests are performed to evaluate the hydro-formability of these materials which is determined by deformation characteristics such as thickness distribution, forming height and branch dome shape. The formabilities obtained from these tests are analysed and compared with the results of the numerical simulation.

The Analysis of Deformation Behavior in Thin Slab Caster (박슬라브 연주주편 변형 거동해석)

  • 배원병;박해두;이호국
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1996.03a
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    • pp.165-171
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    • 1996
  • Recently, to improve the productivity in the continuous casting process, thin slab continuous caster which is one of the new steelmaking technologies by a high speed casting has been introduced. In the process of the thin slab continuous cast, there is more possibility than convnetional one that the deformation be occurred by the bulging of solidified shell, since the thickness of soliidfied shell is very thin as much as 60mm after the casting is finished. In some cases of severe bulging, there might be more breakout. In this paper, using finite difference method , solification analysis of slab is made as well as the thicknessof solidified shell and temperature are calculated. Also, based on the data of the calculated temperature, the deformed behavior of solidified narrow face is anlayzed with the MARC which is a package program for finite element analysis.

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A Study on the Effects of the Process Parameters for the Tube Hydroforming Process (관재 하이드로포밍시 공정인자 영향도에 관한 연구)

  • Kim K. J.;Kim J. W.;Moon Y. H.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2001.05a
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    • pp.49-53
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    • 2001
  • Recently hydroforming process became a process which is increasingly applied in the automotive industry. As the hydroforming process is a new technology, there is no abundant data to assist manufacturing the products. To investigate the effects of process parameters on the tube hydroforming process, simple bulging, circular bulging and Tee-fitting tests are performed. The optimal leading path to escape the failure modes(bursting, wrinkling) is determined and the effects of the process parameters, the internal pressure and axial feeding on the product quality, such as thickness distribution, forming height and branch dome shape are investigated.

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Vibration of Liquid-filled Cylindrical Storage Tank with an Annular Plate Cover (환원판 덮개를 갖는 원통형 연료탱크의 진동해석)

  • 김영완
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.13 no.10
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    • pp.751-759
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    • 2003
  • The theoretical method is developed to investigate the vibration characteristics of the sloshing and bulging mode for the circular cylindrical storage tank with an annular plate on free surface. The cylindrical tank is filled with an inviscid and incompressible liquid. The liquid domain is limited by a rigid cylindrical surface and a rigid flat bottom. As the effect of free surface waves Is taken into account in the analysis, the bulging and sloshing modes are studied. The solution for the velocity potential of liquid movement is assumed as a suitable harmonic function that satisfies Laplace equation and the relevant boundary conditions. The Rayleigh-Ritz method is used to derive the frequency equation of the cylindrical tank. The effect of Inner-to-outer radius ratio and thickness of annular plate and liquid volume on vibration characteristics of storage tank is studied. The finite element analysis is performed to demonstrate the validity of present theoretical method.

A study on Linear Pattern Fabrication of Plate-type Polymer by Using Thermal Nano Imprint Lithography Process (열간나노임프린트공정을 이용한 평판형 폴리머 소재의 선형 패턴 제작에 관한 연구)

  • Joung, Y.N.;Lee, C.S.;Youn, S.W.;Kang, C.G.
    • Transactions of Materials Processing
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    • v.18 no.8
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    • pp.616-624
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    • 2009
  • In this work we demonstrate the hot-embossing process under different forming conditions such as forming temperature, load, and holding time in pressing, in order to determine the suitable conditions required for linear patterning on polymer plates (PC). Results showed that the replicated pattern depth increased in proportion to an increase in the forming temperature, load, and time. The reduction of the workpiece thickness increased according to the holding time in the pressing process. In the process of time, the reduction ratio of the workpiece thickness decreased due to the surface area increment of the workpiece, while the pressure on the workpiece declined. In order to reduce the bulging ratio we introduced a temperature difference between the upper and the lower punch.