곡률을 갖는 셀프-피어싱 리벳 접합시편의 피로수명 평가

김민건,조석수,김동열,Kim, Min-Gun,Cho, Seok-Swoo,Kim, Dong-Youl 한국생산제조학회 2010 한국생산제조학회지 Vol.25 No.3

One of methods that accomplish fuel-efficient vehicle is to reduce the overall vehicle weight by using aluminum structure typically for cross members, rails and panels in body and chassis. For aluminum structures, the use of Self Piercing Rivet(SPR) is a relatively new joining technique in automotive manufacture. To predict SPR fatigue life, fatigue behavior of SPR connections needs to be investigated experimentally and numerically. Tests and simulations on lap-shear specimen with various material combinations are performed to obtain the joining strength and the fatigue life of SPR connections. A Finite element model of the SPR specimen is developed by using a FEMFAT SPR pre-processor. The fatigue lives of SPR specimens with the curvature are predicted using a FEMFAT 4.4e based on the liner finite element analysis.

리드스크루에 사용되는 베어링 스크루의 전산내구해석

김민건(Min-gun Kim),김동열(Dong-youl Kim),조석수(Seok-swoo Cho),김요셉(Yo-seb Kim) 대한기계학회 2011 대한기계학회 춘추학술대회 Vol.2011 No.5

In order to assess the stiffness of bearing screw used for lead screw, finite element analysis on stress and fatigue life of bearing screw has been formed. Based on these analysis, fatigue life dominant model of bearing screw was proposed. This improved model introduces a fillet to release the concentrated stress generated in the vicinity of bearing screw hole. This paper also considered the strength suitability when the bearing screw manufactured in W company was applied to X-ray CT.

한방비만치료임상례중 β3 Adrenergic Receptor 변이율에 대한 고찰

김선민 ( Sun Min Kim ),김동열 ( Dong Youl Kim ),김길수 ( Kil Soo Kim ) 한방비만학회 2002 한방비만학회지 Vol.2 No.1

Purpose & Methods: In order to study obese gene mutation rate in obese Korean patients and to investigate the effect of Chegamuiyiin-tang and electro-lipolysis-acupuncture on obesity treatment, the difference of the reaction to herbal dieting between patients with β3 adrenergic receptor mutation and the patients with wild type β3 adrenergic receptor is observed. Results: Chegamuiyiin-tang and electro-lipolysis-acupuncture treatment are effective on the treatment of obesity in weight reduction, body fat reduction and the circumferences of arm, abdomen, hip and thigh. In the comparison of β3 adrenergic receptor wild type and β3 adrenergic receptor mutation groups, body fat was more reduced with statistical significance, and as for BMI change and body weight change were higher in β3 adrenergic receptor mutation groups with no statistical significance. In the comparison of β3 adrenergic receptor wild type and β3 adrenergic receptor mutation groups among BMI under 25 patients, change rate of body weight, BMI, body fact percentage, WHR and body circumference were higher in β3 adrenergic receptor mutation group than in β3 adrenergic receptor wild type group. Conclusion: These results imply that herbal dieting program combined with electro-lipolysis-acupuncture is more effective on reducing body weight and body fat in β3 adrenergic receptor mutation group than wild type group, and that the earlier the treatment is applied, the more effective it is.

곡률을 갖는 셀프-피어싱 리벳 접합시편의 피로수명 평가

김민건(Min-gun Kim),조석수(Seok-Swoo Cho),김동열(Dong-youl Kim) 한국생산제조학회 2010 한국생산제조학회지 Vol.19 No.1

One of methods that accomplish fuel-efficient vehicle is to reduce the overall vehicle weight by using aluminum structure typically for cross members, rails and panels in body and chassis. For aluminum structures, the use of Self Piercing Rivet(SPR) is a relatively new joining technique in automotive manufacture. To predict SPR fatigue life, fatigue behavior of SPR connections needs to be investigated experimentally and numerically. Tests and simulations on lap-shear specimen with various material combinations are performed to obtain the joining strength and the fatigue life of SPR connections. A Finite element model of the SPR specimen is developed by using a FEMFAT SPR pre-processor. The fatigue lives of SPR specimens with the curvature are predicted using a FEMFAT 4.4e based on the liner finite element analysis.

리드스크루에 사용되는 베어링 스크루의 전산내구해석

김민건(Min-gun Kim),조석수(Seok-swoo Cho),김동열(Dong-youl Kim),김요셉(Yo-seb Kim) 대한기계학회 2011 大韓機械學會論文集A Vol.35 No.12

리드스크루에 사용되는 베어링 스크루의 강성을 평가하기 위해서, 먼저 베어링의 응력과 피로수명의 유한요소해석을 수행하였다. 해석결과의 값을 바탕으로 베어링 스크루의 피로수명이 향상된 모델을 제안하였다. 이 개선된 모델은 베어링 스크루 응력집중부의 응력을 분산시키기 위한 필릿을 도입한 것이다. 또한, W사에서 제작된 베어링 스크루가 단층촬영기에 사용되었을 때 강도측면에서의 적합성 여부를 검토하였다. In order to assess the stiffness of bearing screw used for lead screw, finite element analysis on stress and fatigue life of bearing screw has been performed. Based on these analysis, fatigue life dominant model of bearing screw was proposed. This improved model introduces a fillet to release the concentrated stress generated in the vicinity of bearing screw hole. This paper also considered the strength suitability when the bearing screw manufactured in W company was applied to X-ray CT.

안드로이드 기반의 증강현실 전자사전

김동열,김지수,김진일 東義大學校産業技術開發硏究所 2011 産業技術硏究誌 Vol.25 No.-

본 연구에서는 안드로이드 기반의 전자사전을 개발하는데 있어 증강현실(Augmented Reality)을 적용한 전자사전을 제안한다. 영어 문서를 문자인식을 통해 받아들여 별도의 검색을 위한 작업 소요시간 없이 찾고자 하는 단어를 간단한 터치로만 검색하고, 이를 증강현실을 통해서 사용자에게 감각적으로 전달하여 보다 효율적으로 영어단어를 이해할 수 있도록 구현하였다.

CBN工具에 의한 熱處理鋼(SLEWING RING)의 精密加工

金東烈 三陟大學校 1996 論文集 Vol.29 No.1

We expect that the appearance of cutting difficult material will increase, but CBN sintering tool is the most suitable in cutting steel heated treatment. But the most important thing in high precision product and machining of metals for improving productivity is to choose suitable CBN tool meterial and set the cutting condition. The content is summarized as following. 1) The tool material can be chosen by reference to table 2 and the tool material of BN 250 is suitable for cutting condition of slewing ring is a few discontinuous cutting(Fig.1) 2) Make reference to Fig.16 for cutting condition. The cutting speed is suitable to 120-130m/min, the depth of cut 0.2mm and feedrate 0.15-0.2mm/rev(Fig.8) 3) Tool nose radius is suitable to 0.4mm in consideration of increasing radial force. 4) Use negative tip tool for turning. NL angle is the most optimum in from -25° to -35°for the wear resistance and tool chipping life.(Fig. 17-20) 5) Don't use cutting fluid because of the crack. In the case of using wet method, choose tool material of BN 250.(Photo.4) 6) The problems and settlement in cutting are shown at Table 5.

극저사이클 하중을 받는 구상흑연주철의 초기균열성장에 관한 연구

김민건,임복규,김동열 江原大學校 産業技術硏究所 2002 産業技術硏究 Vol.22 No.A

In this study, extremely low cycle fatigue tests were carried out under push-pull loading conditions using graphite cast iron (GCD). In order to clarify the fatigue fracture mechanism of GCD in an extremely low cycle fatigue regime successive observations of internal fatigue damage were performed. The results obtained are as follows. (1) The process of extremely low cycle fatigue can be classified into three stages which are composed of the generation, growth and coalescence of microvoids inside materials. (2) In an extremely low cycle fatigue regime, microvoids originate from debonding of graphite-matrix interface.

SCM 21 鋼의 表面缺陷形狀이 疲勞龜裂博播에 미치는 影響

金鍾鉉,金棟烈,李龍福 弘益大學校 科學技術硏究所 1991 科學技術硏究論文集 Vol.1 No.-

In this study, the auther investigated propagation behavior of surface Cracks which initiated and propagated from machined defect specimens of SCM 21 which have each other different shape of surface defects. The results are follows. 1. In general, the crack shape was approximately semi-elliptical with the growth the crack. 2. The deeper depth of surface defect, the faster crack length propagation rate than crack depth propagation rate at the beginning but propagation rate of length and depth is similar to increasing the number of repeating load. 3. The shallower depth of surface defect is, the later surface crack are initiated. 4. When the initial surface crack aspect ratio is in the range of 5~6, the initial surface crack is propagated from quter surface to inner surface under the range. In case that ratio is lager than the range, crack is propagated to outer surface.

안드로이드 플랫폼에서 스마트폰 블랙박스 설계 및 구현

황현정;이호섭;전대현;김동열;김진일 東義大學校産業技術開發硏究所 2012 産業技術硏究誌 Vol.26 No.-

본 연구에서는 각종 센서를 통해 교통사고 현장의 상황을 자동으로 저장, 분석할 수 있는 스마트폰 블랙박스를 설계하고 구현하였다. 기존의 웹 캠 형식의 블랙박스 기능을 탈피하고, 사용자가 휴대하기 편한 스마트 폰이라는 장점을 활용해 차량뿐만 아니라 오토바이, 자전거에도 모두 사용가능할 수 있도록 안드로이드 플랫폼을 이용하여 블랙박스 기능을 개발하였다. 또한, 사고발생시 사전에 등록한 번호로 사고위치를 SMS 문자로 전송하여 사고 상황을 노출하도록 설계되었다.