• Title/Summary/Keyword: T-joint Area

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Strength Estimation of T-joint Area of Composite Housing of Medium Range Surveillance Radar (중거리급 탐색레이더 복합재 하우징의 T-joint 영역 구조 강도 평가)

  • Kwon, Min-Sang
    • Journal of the Korea Institute of Military Science and Technology
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    • v.11 no.4
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    • pp.149-158
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    • 2008
  • This article provides strength estimation of T-joint area which made of composite material. Inner and outer structures of medium range surveillance radar are all made of sandwich structure which is made with composite material(CFRP) and aluminum honeycomb core. Since the radar is voluminous and has very complex inner structure, the whole structure cannot be made as one piece. Therefore, usage of T-joints is inevitable. Since some of stress concentration areas were located around T-joint area, series of strength estimations were conducted. Three different configurations were tested to improve mechanical properties(primarily on strength). The results show an improvement on strength to meet calculated strength on stress concentrated T-joint area.

The Effect of a Physical Exercise Program Using Elastic Bands in the Attitude of Physical Exercise and the Degree of Joint Pain (탄력밴드를 이용한 운동이 운동에 대한 태도와 관절운동시 통증 정도에 미치는 효과)

  • Kim, Shin-Jeong;Jeong, Geum-Hee;Yang, Soon-Ok
    • Research in Community and Public Health Nursing
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    • v.18 no.1
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    • pp.79-89
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    • 2007
  • Purpose: The purpose of this study was to identify the effects of a physical exercise program using elastic bands in rural area women. Method: This study adopted a pre-post test design. The subjects were 89 rural area women who were selected from four community health care centers. The physical exercise program was executed 30 times for 10 weeks (3 times a week) from August 23 to October 31, 2003. Results: There was a significant difference in the attitude of physical exercise (t=-5.517, p=.000). In the degree of joint pain, there were significant differences in the flextion and extension of the shoulder joint (t=2.557, p=.020; t=5.625, p=.000), and there was a significant difference in the flextion of the knee joint (t=4.747, 0=.000) but there was no significant difference in the extension of the knee joint (t=1.795, p=.083). Conclusion: Physical exercise programs need to be implemented and spread continuously.

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The Study of Stiffness Evaluation Technique for L, T Shaped Joint Structures Using Normal Modes Analysis with Lumped Mass (모드해석을 이용한 L, T 자형 구조물의 결합 강성 평가 방법에 대한 연구)

  • Hur, Deog-Jae;Jung, Jae-Yup;Cho, Yeon;Park, Tae-Won
    • Journal of KSNVE
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    • v.9 no.5
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    • pp.975-983
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    • 1999
  • This paper describes the dynamic characteristics of the joint structures in case of using the simplified beam model in the F. E. analysis. The modeling errors, when replace the shell with the beam, are investigated through F. E. normal modes analysis. Normal mode analysis were performed to obtain the natural frequencies of the L and T shaped joints with various type of channels. The results were analyzed to access the effects of the models on the accuracy of F.E. analysis by identifying the geometric factors which cause the error. The geometric factors considered are joint angle, channel length, thickness and area ratio of the hollow section to the filled one. The joint stiffness evaluation technique is developed in this study using normal modes analysis with Lumped Mass. With this method, the progressively improved results of F. E. analysis are obtained using the simplified beam model. The static and normal modes analysis are performed with the joint stiffness values obtained by the Kazunori Shimonkakis' virtual stiffness method and the proposed method and these simplified modeling errors are compared.

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Study on seismic behavior of fabricated beam-column bolted joint

  • Zhang, Yu;Ding, Kewei
    • Structural Engineering and Mechanics
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    • v.82 no.6
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    • pp.801-812
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    • 2022
  • To better promote the development of fabricated buildings, this paper studies the seismic behavior of precast concrete beam-column bolted joint under vertical low cyclic loading. The experimental results show that cracks appear in the beam-column joint core area. Meanwhile, the concrete and the grade 5.6 bolts are damaged and deformed, respectively. Specifically, the overall structure of the beam-column joint remains intact, and the bolts have good energy dissipation capacity. Based on the experimental study, a new method of beam-column bolted connection is proposed in simulation analysis. The simulation results show that the bolts deform in the core area of the new beam-column joint, which enhances the concrete shear capacity legitimately and protects the T-end of the beam against shear failure. To summarize, both the experimental joint and the simulated joint prolong the service life by replacing the bolts under the seismic loading. The research results provide a reference for applications of the fabricated beam-column joint.

Failure Behavior of T-joint Pipe with Outer Local Wall Thinning under Internal Pressure (내압을 받는 외부 국부 감육 T-joint 배관의 파손거동)

  • Kim, Soo-Young;Nam, Ki-Woo
    • Journal of Power System Engineering
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    • v.18 no.5
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    • pp.80-87
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    • 2014
  • The pipelines are apt to erosion or corrosion because of the high-speed flow of water and steam with high temperatures or high pressures. This study was carried out a finite element analysis (FEA) and an experimental for the fracture behavior of T-joint pipes with local wall thinning under internal pressure. Local wall thinning was machined on the pipes in order to simulate erosion and corrosion of the metal. The configurations of the eroded area included an eroded ratio of d/t=0.80~0.963 and an eroded length of l=25 mm, 50 mm, and 102 mm. Three-dimensional elastic-plastic analyses were also carried out using FEA, which accurately simulates failure behaviors. In regards to the relationship between pressure and eroded, the criterion that indicates what can be used safely under operating pressure and design pressure were obtained from FEA. The FEA results were in relatively good agreement with that of the experiment.

Weld Quality of MCFC Separators With Large Active Area (MCFC용 대면적 분리판의 용접부 품질에 관한 고찰)

  • Kim, K.C.;Jun, J.H.;Kim, S.G.;Kuk, S.T.;Lim, H.C.;Jung, B.S.
    • 한국신재생에너지학회:학술대회논문집
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    • 2009.11a
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    • pp.135-138
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    • 2009
  • Quality evaluation of laser welded MCFC separator panels with large active area was performed. Lap joint was applied to produce stable air-tight seam weld by employing Nd:YAG laser. Results showed that surface contamination played a key role to form weld defects at the joint interface. However, there was no evidence that weld width at the lap joint changed after the stack operation time of 2,890h. Test results also revealed that the reinforcement values which were measured on the weld line after long time operation, were stable.

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Application of the IoT Concept in the Field of Medical Devices: Development of a Prototype of a Mechanotherapeutic Simulator and Software for Its Control

  • Lasek, Mikhail Petrovich;Karmanov, Vladislav Nikolaevich;Makarov, Roman Vladimirovich;Makarov, Pavel Andreevich;Gryaznov, Dmitriy Yurievich;Ustyugov, Vladimir Aleksandrovich
    • International Journal of Computer Science & Network Security
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    • v.22 no.6
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    • pp.63-66
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    • 2022
  • The article discusses the application of the IoT concept in the sensitive field of medical devices on the example of a developed prototype of a mechanotherapeutic simulator. Mechanotherapy is a complex of therapeutic, preventive, and restorative exercises conducted using simulators, specially designed for developing movements in individual joints. Mechanotherapy is used for the early and painless restoration of joint mobility, to prevent complications associated with prolonged immobilization of the injured area of extremities. Using the mechanotherapy simulator allows developing the joint painlessly, which accelerates the metabolism in the injured area, and soft tissues are restored to normal. The article provides information about the electronic components that ensure the wireless operation of the device and describes in detail the applied software as well as the client application for a mobile device.

Atlanto-Axial Joint Block -Case reports- (환추축관절 차단술 -증례 보고-)

  • Shin, Keun-Man;Yun, Seon-Hye
    • The Korean Journal of Pain
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    • v.12 no.2
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    • pp.231-234
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    • 1999
  • Until several years ago we didn't think seriously about cervical problems as a cause of headaches, but since the publication of articles by Bogduk et al they have gotten more attention. Cervical headaches are associated with movement abnormalities of the structures of the neck such as cervical nerve roots, discs, joints and soft tissues. Considering this, we thought that the atlanto-axial joint could be one of the causes of these headaches. Headaches originating from this joint can be recognized by the fact that the pain worsens with rotation of the head in the horizontal plane. Pain can also be referred to the frontal area or around the orbit. We did atlanto-axial joint blocks using a posterior approach on 10 patients who suffered from this type of headache. The results were promising with 9 out of 10 patients showing more than 50% improvement on the numeric rating scale. There were no serious complications observed. We concluded that the atlanto-axial joint block can be an effective procedure in treating this specific type of headache.

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A Study on Electrically Assisted Solid State Joining of Aluminum and Copper (알루미늄과 구리 간 통전고상접합 연구)

  • Park, J.W.;Choi, H.;Lee, S.;Jeong, H.J.;Hong, S.T.;Han, H.N.
    • Transactions of Materials Processing
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    • v.29 no.1
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    • pp.49-54
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    • 2020
  • The influence of electric current on the joining properties of aluminum and copper was investigated. Various pulsed electric current conditions were set to the joining specimens followed by pressure. The shear strength of the joint area between aluminum and copper was measured by the lab shear test. In addition, the microstructures of the joint area were observed through a field emission scanning electron microscope, energy dispersive X-ray, and electron backscatter diffraction. The mechanical properties of each phase in the joint region were measured by nano-indentation. As a result, it was confirmed that electrically assisted solid state joining of copper and aluminum could be applied in various industrial fields.