• Title/Summary/Keyword: Groove Joint

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Arthroscopic Findings of the Canine Stifle Joint (정상견 무릎의 관절경 검사소견)

  • 정순욱;정월순
    • Journal of Veterinary Clinics
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    • v.16 no.2
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    • pp.300-308
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    • 1999
  • Arthroscopy is a valuable diagnostic and operative tool in equine and human orthopedics. The arthroscope is a difficult instrument to use and requires patience, practice, and persistence in order to obtain good results. This technique was found to be less traumatic than arthrotomy, invasiveness, rapid recovery and the feasibility of surgically correcting many arthropathies. The use of the arthroscope in the dog provides a new dimension in the study and diagnosis of joint derangements. The purpose of this report is to introduce the use of the arthroscope in the dog-more specifically, in the stifle of the dog. A diameter 2.7 mm fore-oblique viewing arthroscope, cold light source, video and video printer are used. With the fore-oblique viewing type it is possible to view directly as well as slightly to the side and the range of viewing can be increased by rotating the arthroscope around the object The scope is connected with a cold light source by means of a fiber-optic light guide. The stifle joint was flexed to 20~30$^{\circ}$. The joint were lavaged with lactated Ringer's solution during arthroscopic examination. Arthroscopy of the stifle was performed prior to arthrotomy in 1 dead dog and 4 healthy dogs, and other 3 dogs was performed only arthroscopic examination. In this study only the conventional approaches were used and in most cases it was possible to view all the intra-articular structures via the lateral infrapatellar approach. In the stifle joint, endoscopic observation was performed to find lateral femoral condyle, patella, medial femoral condyle, trochlear groove, tibia, fat, cranial cruciate ligament, caudal cruciate ligament lateral meniscus, tendon of long digital extensor muscle, medial meniscus, and medial collateral ligament Post-arthroscopic examination, the lameness had disappeared within 12~24 hours. Pain and swelling in the stifle joint had disappeared within 24~36 hours. Post-arthroscopic secondary infection was never encountered in the dogs. In conclusion, arthroscopic insertion technique in canine stifle joint using a diameter 2.7 mm 30$^{\circ}$ arthroscope was established and arthroscopical views of all anatomical structures in the normal stilfe joint were obtained through lateral infrapatellar portal.

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Distribution of Welding Residual Stresses in T-joint Weld with Root Gap (루트부 갭이 있는 양면 필릿용접 이음부의 용접잔류응력 분포)

  • H.S. Bang;S.H. Kim;Y.P. Kim;C.W. Lee
    • Journal of the Society of Naval Architects of Korea
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    • v.39 no.3
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    • pp.81-88
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    • 2002
  • The root joint in the welding structures are apt to failure by the stress concentration which is occurred by the external force. Therefore, in the safety and reliability of structure, the complete penetration joint welding which are obtained by the groove welding with edge preparation is generally required. Nevertheless, fillet T-joint welding without edge preparation is often carried out in the fields to reduce working time and consumption of welding electrode, however, this process is likely to produce inadequate joint penetration such as root gap. In this paper, the focus of research is to investigate distribution of welding residual stresses in the plate(or flange) and web of T-joint weld, and especially in the near of root gap notch that is due to incomplete joint penetration. For the analysis, we have chosen model of T-joint weld in the cases of single and multi-pass welding with submerged arc welding and analyzed model by using finite element programs considering the heat conduction and thermal elasto-plastic theory.

A Study on the compensation margin on butt welding joint of large steel plates in shipyards (조선해양 구조물 주판의 Butt welding joint 수축에 관한 연구)

  • Kim, Jeongtae;Lee, Daechul;Jeong, Hyomin;Chung, Hanshik
    • Journal of Advanced Marine Engineering and Technology
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    • v.37 no.5
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    • pp.461-466
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    • 2013
  • This paper examines the characteristics of butt welding joint shrinkage for shipbuilding and marine structures main plate. The shrinkage strain of butt welding joint which is caused by the process of heat input and cooling, results in the difference between dimensions of the actual parent metal and the dimensions of design. This, in turn, leads to poor quality in the production of ship blocks and reworking through period of correction brings about impediment on improvement of productivity. Through experiments on butt welding joint's shrinkage strain on large structures main plate, the deformation of welding residual stress in the form of I, Y, V was obtained. In addition, the results of experiments indicate that there is limited range of shrinkage in the range of 1 ~ 2 mm in 11t ~ 21.5t thickness and the effect of heat transfer of weld appears to be limited within 1000mm based on one side of seam line so there was limited impact of weight of parent metal on the shrinkage. Finally, it has been learned that Shrinkage margin needs to be applied differently based on groove phenomenon in the design phase in order to minimize shrinkage.

Residual Stress and Fracture Analysis of Thick Plate for Partial Penetration Multi-Pass Weldment

  • Kim, Seok;Shim, Yong-Lae;Song, Jung-Il
    • Journal of Mechanical Science and Technology
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    • v.16 no.9
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    • pp.1033-1039
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    • 2002
  • Partial penetration welding joint refers to the groove weld that applies to the one side welding which does not use steel backing and to both side welding without back gouging, that is, the partial penetration welding joint leaves an unwelded portion at the root of the welding area. In this study, we analyzed the residual stress and fracture on the thick metal plates that introduced the partial penetration welding method. According to the above-mentioned welding method, we could draw a conclusion that longitudinal stress and traverse stress occurred around the welding area are so minimal and do not affect any influence. We also performed the fracture behavior evaluation on the partial penetration multi pass welding with 25.4 mm thick plate by using the J-integral, which finally led us the conclusion that the partial penetration multi-pass welding method is more applicable and effective in handling the root face with less than 6.35 mm.

A Study on a Visual Sensor System for Weld Seam Tracking in Robotic GMA Welding (GMA 용접로봇용 용접선 시각 추적 시스템에 관한 연구)

  • 김동호;김재웅
    • Journal of Welding and Joining
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    • v.19 no.2
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    • pp.208-214
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    • 2001
  • In this study, we constructed a visual sensor system for weld seam tracking in real time in GMA welding. A sensor part consists of a CCD camera, a band-pass filter, a diode laser system with a cylindrical lens, and a vision board for inter frame process. We used a commercialized robot system which includes a GMA welding machine. To extract the weld seam we used a inter frame process in vision board from that we could remove the noise due to the spatters and fume in the image. Since the image was very reasonable by using the inter frame p개cess, we could use the simplest way to extract the weld seam from the image, such as first differential and central difference method. Also we used a moving average method to the successive position data or weld seam for reducing the data fluctuation. In experiment the developed robot system with visual sensor could be able to track a most popular weld seam. such as a fillet-joint, a V-groove, and a lap-joint of which weld seam include planar and height directional variation.

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A study on weld distortion in butt and fillet welds of a steel plate by flux cored arc welding (플럭스코어드 용접으로 맞대기 및 필렛 용접된 판의 용접변형)

  • 안성철;유순영;조성택
    • Journal of Welding and Joining
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    • v.7 no.4
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    • pp.22-29
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    • 1989
  • In this paper weld distortion both in butt and fillet welds by flux cored arc welding has been investigated by changing welding parameters such as heat input and plate thickness, and the weld distortion was expressed as a function of welding parameters adopting the inherent strain theory as proposed by Watanabe and Satoh in 1961. As results of the research it is proposed that transverse shrinkage in root pass butt welds in proportional to ln[(Q/t_-tan.theta.] where Q is heat input(cal/mm), t is plate thickness(mm), and 2.theta. is groove angle(degree), and angular distortion .phi.(radian) in one pass of fillet welds has the following relationship: .phi..var.(Q/ $t^{1.5}$)$^{3}$exp[-(Q/ $t^{1.5}$ )$^{2}$3/] These equations provide us with basic tools to predict the amount of weld distortion in welded structures.

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An Arc Sensor and Its Interface System for Welding Robots (용접로봇용 아크센서 및 인터페이스 시스템)

  • 오승준;김재웅
    • Journal of the Korean Society for Precision Engineering
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    • v.17 no.1
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    • pp.76-82
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    • 2000
  • An arc sensor system to compensate positional errors was developed on the foundation of sensor interface system to make use of the on-line shift function of industrial welding robot. Investigating the on-line shift function, we examine the quantitative relationship between the deviation from programmed path and the correction data transferred from personal computer to robot controller. The number of input parameters for weld seam tracking can be reduced by making the relationship between the deviation and the correction data during half weaving be the function of only cross time. With the results of weld seam tracking for the butt joint with V-groove and fillet joint of sheet metal, good performance was implemented. By developing the sensor interface system to compensate the positional errors, industrial welding robot can be expected to contribute to the promotion of welding automation.

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Magnetic resonance imaging features of the biceps tendon rupture in a Labrador retriever dog

  • Cho, Hyunju;Choi, Hojung;Lee, Youngwon
    • Korean Journal of Veterinary Research
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    • v.60 no.4
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    • pp.233-236
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    • 2020
  • A five-year-old spayed female Labrador retriever presented with right forelimb lameness one day earlier. Radiographs and computed tomography of the right shoulder joint revealed conspicuous enthesophytes, bone cyst, and bone fragment at the intertubercular groove. Magnetic resonance imaging showed a loss of continuity of the biceps tendon and inhomogeneous hyperintense signal of the surrounding soft tissue and moderate synovial fluid on T2- and proton density-weighted images with contrast enhancement on the postcontrast T1-weighted images. The dog was diagnosed with tenosynovitis and biceps tendon rupture with osteoarthritis based on a comprehensive evaluation of the computed tomography and magnetic resonance imaging features.

A Study on the Forming Characteristics of Clinching Joint Process (크린칭 접합의 성형특성에 관한 연구)

  • Jayasekara, V.R.;Noh, J.H.;Hwang, B.B.;Ham, K.C.;Jang, D.H.
    • Transactions of Materials Processing
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    • v.16 no.8
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    • pp.603-613
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    • 2007
  • This paper is concerned with joining of thin metal sheets by single stroke clinching process. This method has been used in sheet metal work as it is a simple process and offers the possibility of joining similar-dissimilar thin sheet metals. Clinching generates a joint by overlapping metal sheets deforming plastically by punching and squeezing sequence. AA 5754 aluminum alloy of 0.5 mm thick sheets have been selected as a modal material and the process has been simulated under different process conditions and the results have been analyzed in terms of the quality of clinch joints which are influenced mainly by tool geometries. The rigid-plastic finite element method is applied to analyses in this paper. Analysis is focused mainly on investigation of deformation and material flow patterns influenced by major geometrical parameters such as die diameter, die depth, groove width, and groove corner radius, respectively. To evaluate the quality of clinch joints, four controlling or evaluation parameters have been chosen and they are bottom, neck thickness of bottom and top sheets, and undercut thickness, respectively. It has been concluded from the simulation results that the die geometries such as die depth and diameters are the most decisive process parameters influencing on the quality of clinch joints, and the bottom thickness is the most important evaluation parameter to determine if the quality of clinch joints satisfies the demand for industrial application.

Fracture Analysis of Thick Plate for Partial Penetration Multi-pass Weldment Using J-integral (J-적분을 이용한 후판 부분용입 다층용접재의 파괴 해석)

  • Kim, Seok;Song, Jung-Il
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.2
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    • pp.300-307
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    • 2002
  • Partial penetration welding joint is defined as groove welds welded from one side, without steel backing or groove welds welded from both sides but without back gouging. So it has an unwelded portion at the root of the weld. Study of partial penetration weldment fracture behavior includes residual stress analysis and fracture analysis. The J-integral loses its path independency in residual stress field. Therefore, it is necessary to introduce a new J-integral, J, which is defined including the effect of plastic deformation and thermal strain. In this study, theoretical formulation and program were developed for the evaluation of J-integral for the crack tip located in the weldment. Evaluations of fracture behavior were performed for partial penetration multi-pass weldment of 25.4mm thick plate by J-integral. From a point of fracture in partial penetration multi-pass welding, it seemed to be better to control root face smaller than 6.35mm.