• Title/Summary/Keyword: L-joint

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A Study on Fatigue Design of STS301L Fillet Welded Joint (STS 301L 필렛 용접이음재의 피로설계에 관한 연구)

  • Baek, Seung-Yeb
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.34 no.5
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    • pp.561-565
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    • 2010
  • Stainless steel sheets are widely used as structural materials for the manufacture of railroad cars and commercial vehicles. These kinds structures used stainless steel sheets are commonly fabricated by using the gas welding. For the fatigue design of gas welded joints such as fillet joints and plug joints, it is necessary to obtain information on the stress distribution at the weldment and the fatigue strength of the gas welded joints. Moreover the influence of the geometrical parameters corresponding to the gas welded joints on the stress distribution and fatigue strength must be evaluated. ${\Delta}P-N_f$ curves were obtained from the data recorded in fatigue tests. Using these results, the ${\Delta}P-N_f$ curves were rearranged according the relation between $\Delta\sigma-N_f$ and the maximum stress at the edge of the fillet welded joint.

Control of Inertially Stabilized Platform Using Disturbance Torque Estimation and Compensation (외란토크 추정 및 보상을 이용한 관성안정화 플랫폼의 제어)

  • Choi, Kyungjun;Won, Mooncheol
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.40 no.1
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    • pp.1-8
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    • 2016
  • In this study, we propose a control algorithm for Inertially Stabilized Platforms (ISP), which combines Disturbance Observer (DOB) with conventional proportional integral derivative (PID) control algorithm. A single axis ISP system was constructed using a direct drive motor. The joint friction was modeled as a nonlinear function of joint speed while the accuracy of the model was verified through experiments and simulation. In addition, various Q-filters, which have different orders and relative degrees of freedom (DOF), were implemented. The stability and performance of the ISP were compared through experimental study. The performance of the proposed PID-plus-DOB algorithm was compared with the experimental results of the conventional double loop PID control under artificial vehicle motion provided motion simulator with six DOF.

Evaluation of Fatigue Life of Welded Joint of Gear Box-Shank in Vibro Ripper Using P-S-N Curve (P-S-N선도를 이용한 진동리퍼 기어박스-생크 용접부의 피로수명 평가)

  • Oh, Kwang Keun;Kim, JaeHoon;Park, Jung Yeol;Yang, GyuSang;Park, JongWon;Kim, Sung Hyun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.39 no.12
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    • pp.1207-1212
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    • 2015
  • A vibro ripper utilizes high-frequency vibration for rock fragmentation. This concept is different from those used by other existing breakers. The gearbox-shank welded joint of a vibro ripper is a very important part. Because it delivers the vibromotive force to the tooth, it is important to predict its soundness. This study was conducted to predict the fatigue life under welding conditions. The shank materials were Hardox-Hituf and AR400, and the filler metals were CSF-71T and CSF-81T. Fatigue tests were conducted under each set of conditions. P-S-N curves are presented based on the statistical testing method recommended by JSME-S002, and a comparison is made of the results under each set of conditions. The life was estimated using a P-S-N curve.

Real-time evaluation of automatic production quality control for friction welding machine (摩擦熔接機械 의 自動생산品質制御 實時間 評價)

  • 오세규;임우조;김형자
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.9 no.6
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    • pp.757-766
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    • 1985
  • Both in-process quality control and high reliability of the weld is one of the major concerns in applying friction welding to the economical and qualified mass-production. No reliable nondestructive monitoring method is available at present to determine the real-time evaluation of automatic production quality control for friction welding machine. This paper, so that, presents the experimental examinations and statistical quantitative analysis of the correlation between the initial cumulative counts of acoustic emission(AE) occurring during plastic deformation period of the welding and the tensile strength of the welded joints as well as the various welding variables, as a new approach which attempts finally to develop an on-line (or real-time) quality monitoring system and a program for the process of real-time friction welding quality evaluation by initial AE cumulative counts. As one of the important results, it was well confirmed that the initial AE cumulative counts were quantitatively and cubically correlated with reliability of 95% confidence level to the joint strength of the welds, bar-to-bar (SCM4 to SUM31, SCM4 to SUM24L) and that an AE technique using initial AE counts can be reliably applied to real-time strength evaluation of the welded joints, and that such a program of the system was well developed resulting in practical possibility of real-time quality control more than 100% joint efficiency showing good weld with no micro-structural defects.

Intra-articular Injection of $IL-1{\beta}$ Facilitated Formalin-induced Temporomandibular Joint Pain in Freely Moving Rats

  • Choi, Hyo-Soon;Jung, Sung-Chul;Choi, Byung-Ju;Ahn, Dong-Kuk
    • The Korean Journal of Physiology and Pharmacology
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    • v.9 no.1
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    • pp.23-27
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    • 2005
  • The present study was performed to investigate the effects of intra-articular injection of interleukin-1${\beta}$ (IL-1${\beta}$) on the formalin-induced temporomandibular joint (TMJ) pain. Under anesthesia, a 30-gauge needle was introduced into the right TMJ region for injection of formalin. Microinjection of 50 ${\mu}l$ of 5% formalin significantly produced noxious scratching behavioral response, and the scratching behavior lasted for 40 min. Although the responses produced by formalin injection were divided into two phases, the response of 1st phase did not significantly differ from the scratching behavior response in the saline-treated group. We examined the effects of intra-articular injection of IL-1${\beta}$ on the number of noxious behavioral responses produced by 50${\mu}l$ of 5% formalin injection. Intra-articular injection of 100 pg and 1 ng of IL-1${\beta}$ significantly increased the number of behavioral responses of the 2nd phase, while 10 pg of IL-1${\beta}$ did not change the formalin-induced behavioral responses. To investigate whether IL-1 receptor was involved in the intra-articular administration of IL-1${\beta}$-induced hyperalgesic response, IL-1 receptor antagonist (IL- ra, 50 ng) was administrated together with IL-1${\beta}$ injection. IL-1${\beta}$ receptor antagonist blocked IL-1${\beta}$- induced hyperalgesic response in the TMJ formalin test. These results suggest that intra-articular injection of IL-1${\beta}$ facilitated the transmission of nociceptive information in the TMJ area.

Usage of Internet-based Oceanographic GIS of the NW Pacific for Joint Analysis of Satellite and sub-Satellite Data

  • Golik A.V.;Fischenko V.K.;Dubina V.A.;Mitnik L.M.
    • Proceedings of the KSRS Conference
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    • 2004.10a
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    • pp.371-374
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    • 2004
  • The task of development and usage in a corporate computer network of the Far Eastern Branch of the Russian Academy of Sciences (FEB RAS) of integrated technology of joint use by the scientists of satellite and sub satellite data on a Northwestern Pacific is considered. This integrated technology is realized by embedding of satellite data in the corporate oceanographic GIS of FEB RAS as a new information layer, and also by support of GIS by program techniques for specialized processing of both kinds of the data. As a result of integration the specialists of FEB RAS have an opportunity to carry out coordinated samples of satellite and various oceanographic data as a function of area, time and other important conditions, visualize them together and carry out analytical processing with the usage of the GIS tools. Application of the realized approach to improve the techniques of detection and description of the oceanic phenomena on ERS-l and ERS-2 SAR images as well as to improve of perspective techniques of the usage the brightness temperatures measured by a microwave radiometers AMSR-E on a board of Aqua (USA) satellites are discussed.

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The Prediction of Yield Load in Circular Tubular T-type Cross Sections on the Truss Structures (강관트러스의 T형 격점부의 항복하중 예측에 관한 연구)

  • Park, Il Min
    • Journal of Korean Society of Steel Construction
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    • v.13 no.1
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    • pp.9-18
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    • 2001
  • many steel tubular truss as roof structures are used of the large span structures Steel tubular sectioned truss has the structural merits in compared with other sections such as H, L-shape sections However it occurs local buckling at the joint of branch in truss and it makes the deterioration of loading capacity Loading capacity and deformation characteristics of truss joints are very complicate so it is very hard to predict exact solution of them Therefore this thesis dealt with T-type joints of steel circular hollow sectioned truss. A series of experimental scheme were planned and mainly experimental parameters were : ratio of diameter of branch-diameter of main chord(d/D). diameter-thickness(T/D) of main chord. In this paper predicted yield load capacity using by closed ring analysis method additionally compared with that of suggested by closed ring analysis method additionally compared with that of suggested by other countries.

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Accelerated Life Prediction for STS301L Gas Welded Joint (I) - Fillet Type - (STS301L 가스용접 이음재의 가속수명예측 (I) - Fillet Type -)

  • Baek, Seung-Yeb
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.34 no.4
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    • pp.467-474
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    • 2010
  • Stainless steel sheets are widely used as the structural material for railroad cars and commercial vehicles. Structures made of stainless steel sheets are commonly fabricated by gas welding, For the fatigue design of gas welded joints such as fillet joints, it is necessary to obtain design information of the stress distribution at the weldment as well as the fatigue strength of the gas-welded joints. Further, the influence of the geometrical parameters of gas-welded joints on stress distribution and fatigue strength must be evaluated. in this study, ${\Delta}P-N_f$ curves were obtained by fatigue tests. and, the ${\Delta}P-N_f$ curves were rearranged on the basis of the ${\Delta}{\sigma}-N_f$ relation for the hot-spot stresses at the gas-welded joints. These results, were used for conducting an accelerated life test(ALT) From the experiment results, an acceleration model was derived and factors were estimated. The objective is to obtain the information required for the analysis of the fatigue lifetime of fillet welded joints and for data analysis by the statistic reliability method to save time and cost and to develop optimum accelerated life prediction plans.

A Study on the Spot Welding and Fatigue Design of High Strength Steel Sheets for Light Weight Vehicle Body (경량 차체용 고장력 강판의 Spot 용접과 피로설계에 관한 연구)

  • Heo, Jeong-Beom;Bae, Dong-Ho;Yoon, Chi-Sang;Kwon, Soon-Yong
    • Proceedings of the KSME Conference
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    • 2003.11a
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    • pp.1115-1120
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    • 2003
  • The recent tendency in the automobile industries is toward light weighting vehicle body to improve the problems by environmental pollution as well as improving fuel cost. The effective way to reduce the weight of vehicle body seems to be application of new materials for body structure and such trend is remarkable. Among the various materials for vehicle body, stainless steel sheet (for example, 301L and 304L), TRIP steel and cold rolled steel sheets are under the interests. However, in order to guarantee reliability of new material and to establish the long life design criteria of body structure, it is important and require condition to assess spot weldability of them and fatigue strength of spot welded lap joints which were fabricated under optimized spot welding condition. And, recently, a new issue in the design of the spot welded structure is to predict economically fatigue design criterion without additional fatigue tests. In general, for fatigue design of the spot-welded thin sheet structure, additional fatigue tests according to the welding condition, material, joint type, and fatigue loading condition are generally required. This indicates that much cost and time for it should be consumed. Therefore, in this paper, the maximum stresses at nugget edge of spot weld were calculated through nonlinear finite element analysis first. And next, obtained the ${\Delta}P-N_{f}$ relation through the actual fatigue tests on spot welded lap joints of similar and dissimilar high strength steel sheets. And then, the ${\Delta}P-N_{f}$ relation was rearranged in the ${\Delta}{\sigma}-N_{f}$ relation. From this ${\Delta}{\sigma}-N_{f}$ relation, developed the fatigue design technology for spot welded lap joints of them welded using the optimized welding conditions.

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Surgical treatment of the Acute Acromioclavicular Dislocation (견봉 쇄골 관절의 급성 완전탈구에 대한 수술적 치료)

  • Lee Kwang-Won;Hwang In-Sik;Choy Won-Sik
    • Clinics in Shoulder and Elbow
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    • v.1 no.2
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    • pp.175-179
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    • 1998
  • The acromioclavicular joint is commonly affected by traumatic and degenerative conditions. Most injuries are due to direct trauma, such as a fall on the shoulder. Although there is general agreement on treatment of type I, Ⅱ, Ⅳ, V and VI acromioclavicular injuries, the treatment of type Ⅲ injuries remains controversial. Sixty patients, ranging in age from 19 to 57 years(average, 32), were evaluated an average of 57.5 (range, 13 to 96) months after surgical reconstruction for Rockwood type Ⅲ Ⅳ, V acromioclavicular dislocation. Phemister method (47 cases), Bosworth (3 cases), Weaver and Dunn method (10 cases) were used to correct displacement. An increase of the coracoclavicular distance of the injured shoulder over the normal shoulder was average 7.1㎜ at initial, average l㎜ on postoperatively, and average 2㎜ at follow-up. Overall, 54 of 60(90%) patients achieved satisfactory results. Degree of increase of the coracoclavicular distance has no inliluence to clinical results.

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