유용성 도료와 수용성 도료의 유해성 비교에 관한 연구 : 자동차 보수용 도료를 중심으로

권은혜,김광식,오정룡,최정근,정윤석,이유진,김은아,송세욱,정호근 한국산업위생학회 2001 한국산업보건학회지 Vol.11 No.1

The purpose of this study is to substitute water-based painting materials for the current solvent-based ones used in motor-repairing process to minimize the exposure of organic solvents to the painters. This study assessed the exposure of organic solvents to the painters using water-based and solvent-based painting materials and compared compositions, painting processes and the health hazards of the application of these alternative painting materials. The results of this study are as follows. 1. solvent-based painting materials used in motor-repairing process consist of various organic solvents, which consist primarily of toluene, xylene, ethyl benzene, ethyl methyl bezene, trimethyl bezene, ethyl acetate, butyl acetate, methyl isobutyl ketone, 2-ethoxy ethanol, 2-ethoxy ethyl acetate and toluene-2.4-diisocianate and the others. These organic solvents are know as health-hazardous substances. But water-based painting materials are high-solid, low-solvent ones and consist of such two organic solvents as 2-butoxy ethanol and 2-heptanone and the others. 2. The painters using solvent-based painting materials in motor-repairing process are exposed to various organic acetate, methyl isobutyl ketone, trimethyl benzene, 2-ethoxy ethanol, and 2-ethoxy ethyl acetate. But the painters using solvent-based ones are only exposed to 2-butoxy ethanol and 2-heptanone. 3. By using water-based painting materials in stead of solvent-based painting materials containing health-hazardous organic solvents, the exposure of such organic solvents in the painter's breathing zone can be largely prevented. 4. This study recommends water-based painting materials as substitutes for the current solvent-based ones used in motor-repairing process to minimize the exposure of organic solvents to the painters.

노인 낮병원의 심리사회적 치료 프로그램이 노인의 신경인지기능과 우울 증상에 미치는 효과

유계준,송정은,오병훈,안석균,이홍식,오희철,구은형,황혜숙,이은철 大韓神經精神醫學會 1999 신경정신의학 Vol.38 No.5

노인에게 있어서 신경인지기능의 저하와 우울 증상은 가장 흔한 장애이며 신체적, 정신적인 면에 많은 영향을 미치고 있다. 또한 이러한 장애중 비임상군에서 심리사회적 치료개입의 효과가 보고되고 있다. 이러한 측면에서 지역사회에서 노인에게 제공되는 심리사회적 치료개입의 중요성이 높아지고 있다. 이전의 연구에서는 대상이 특정 집단이거나, 비교군이 없거나, 치료효과에 대한 추적 관찰이 이루어지지 않는 등의 제한점이 있었으며, 현재 국내의 노인 낮병원은 소수에 불과하고 이러한 낮병원의 치료효과에 대한 연구는 거의 없는 실정이다. 따라서 본 연구는 지역사회 정신보건센터에서 운영하는 노인 낮병원에 참가하는 노인들을 대상으로 낮병원의 심리사회적 프로그램이 노인들의 신경인지기능과 우울 증상에 미치는 효과와 이에 대한 유지 효과의 유무를 알아보고자 하였다. 경기도 광주군 정신보건센터의 노인 낮병원에 참여한 노인을 치료군으로, 치료를 거부하거나 치료 중 탈락한 노인을 비교군으로 하여 10주간의 낮병원 치료전후와 치료종결 후 10주에 신경인지기능은 한국형 간이 정신상태검사(이하 MMSE-K)로, 우울 증상은 단축형노인우울척도(이하 SGDS)로 평가하여 두 군을 비교하였고 치료군의 치료 직후와 치료종결 후 10주를 비교하였다. 연구결과 노인 낮병원의 심리사회적 치료가 시간에 따른 SGDS점수 변화에 통계학적으로 유의한 영향을 미쳤으며, MMSE-K점수 변화에는 통계학적으로 유의한 영향을 미치지 않았다. 또한 10주 추시가 가능했던 치료군 중 약 43%가 10주 후 SGDS가 증가하여 호전되었던 우울증상의 악화를 보였다. 본 연구 결과 노인 낮병원의 심리사회적 치료 프로그램 개입은 노인에게 있어서 우울 증상을 호전시키며 신경인지 기능에는 직접적인 영향을 미치지 않는 것을 알 수 있었다. 또한 상당수에서 심리사회적 치료 개입으로 인한 우울 증상의 호전이 유지되지 않음을 알 수 있었다. 이는 노인우울증상의 치료에 낮병원의 심리사회적 치료 프로그램이 효과적일 수 있음과 치료 후 이를 유지하기 위한 부가적인 치료개입의 필요성을 시사한다. Cognitive impairment and depression are the most common symptoms affecting the elderly on physical and mental states. Studies have shown that these symptoms in mild cases are improved by psychosocial intervention, emphasizing the importance of therapeutic intervention provided in the community. The purpose of this study was to investigate whether the psychosocial program at a geriatric day care service has any therapeutic effect on the cognitive function and depressive symptoms in the elderly and whether such effect can be maintained. The experimental group was composed of 37 elderly patients attending the day care service at the mental health center located in Kwangju county, Kyonggi province. The control group was composed of 22 elderly patients who either refused intervention or who dropped out of the program. Cognitive function was assessed with the Korean version of the Mini-Mental State Exam(MMSE-K), and depressive symptoms were assessed with the Short-form Geriatric Depression Scale(SGDS). The experimental group and the control group were compared on the score of on each test, which was administered before and after the program and 10 weeks after discontinuation of program. In the experimental group, the scores acquired immediately after the program and at 10 weeks of follow-up were also compared. The results showed that psychosocial intervention at a geriatric day care service was significantly associated with the change in SGDS scores dependent on time but not significantly associated with the change in MMSE-K scores. In the experimental group whose follow-up assessment was possible, it was further shown that 43% of patients had increased SGDS scores 10 weeks after the program ended, indicating that depressive symptoms had worsened. This study suggests that psychosocial therapeutic intervention in the geriatric day care service improve depressive symptoms but not cognitive functions in the elderly. In addition, for a considerable percentage of subjects in the experimental group, the improvements in depressive symptoms were not sustained after the intervention was withdrawn. These findings proposes a need of strengthening therapeutic intervention to maintain such effect.

PBDEs and their structural analogues in marine environments: Fate and expected formation mechanisms compared with diverse environments

Choo, Gyojin,Kim, Da-Hye,Kim, Un-Jung,Lee, In-Seok,Oh, Jeong-Eun Elsevier 2018 Journal of hazardous materials Vol.343 No.-

<P><B>Abstract</B></P> <P>The concentrations and relative distributions of 27 polybrominated diphenyl ethers (PBDEs) and 17 methoxylated (MeO-) and 8 hydroxylated (OH-) BDEs were determined in marine environments including sediments, bivalves, and seawater along the southern coast of South Korea to understand their fates and possible formation mechanisms. The relative and substituent distributions of the PBDEs and their structural analogues varied according to the characteristics of the media. PBDEs were dominant in marine sediments and seawater, whereas MeO-BDEs made the highest contributions in bivalves. Similar patterns were previously identified in inland environments in Korea, except in river water where OH-BDEs were dominant. The natural formation of structural analogues might be the main mechanism in marine, as <I>ortho</I>-substituted naturally occurring MeO- and OH-BDEs were dominant in all media and seemed to be more produced than in inland environments. In addition, the higher concentrations of meta-substituted MeO-BDEs nearshore than offshore was observed. This is the first study comparing marine (near- and offshore) and inland to understand the differences in their fate and possible formation mechanisms in each environmental conditions.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The distributions of PBDEs and their structural analogues were compared between marine (near- and offshore) and inland. </LI> <LI> PBDEs dominated in abiotic media, whereas MeO-BDEs were dominant in biota. </LI> <LI> Natural formation might be the main mechanism for PBDE structural analogues in marine and was highly occurred than in inland. </LI> <LI> The higher contributions of meta-MeO-BDEs were observed in inland and nearshore than offshore. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Systematic Review of Heavy Metal Concentrations in Fish and Shellfish in Korea

Shinhee Ye,Jiyoung Shin,Jueun Lee,Eun Mi Jung,Jeongsook Lee,Eunsun Yun,Yeosook Kim,Younghee Oh,Eun-Hee Ha 이화여자대학교 의과학연구소 2018 EMJ (Ewha medical journal) Vol.41 No.1

Objectives: Heavy metals ingested through the consumption of aquatic products can accumulate in the human body over the long-term and cause various health problems. This study aims to present comprehensive data on the amount of heavy metals found in fish and shellfish in Korea using a systematic review of studies that report on that issue. Methods: The study used the following databases: PubMed, Korean Studies Information Service System, and Research Information Sharing Service. The search terms for PubMed included fish OR shellfish OR seafood AND mercury OR cadmium OR lead OR heavy metal AND Korea. The search terms for Korean Studies Information Service System and Research Information Sharing Service included eoryu sueun, eoryu kadeumyum, eoryu nab, eoryu jung-geumsog, paeryu sueun, paeryu kadeumyum, paeryu nab, paeryu jung-geumsog, eopaeryu sueun, eopaeryu kadeumyum, eopaeryu nab, and eopaeryu jung-geumsog. Results: A total of 32 articles were selected for review. The total mercury, lead, and cadmium concentrations in fish and shellfish reported in each of the articles are summarized, as are the species of fish and shellfish with relatively high concentrations of heavy metals. Total mercury concentrations tended to be higher in predatory fish species, such as sharks, billfishes, and tuna, while lead and cadmium concentrations tended to be higher in shellfish. Conclusion: This paper is the first to report a comprehensive summary of the concentrations of heavy metals in fish and shellfish. This data could be used as evidence to protect Koreans from exposure to heavy metals due to the consumption of highly polluted aquatic products.

풋마늘의 冬季養液裁培에 關한 硏究

鄭恩周,吳仲烈,黃海鎭,韓相政 대구효성가톨릭대학교 응용과학연구소 1995 응용과학연구논문집 Vol.4 No.-

겨울철 新鮮한 풋마늘의 生産體系 確立으로 端境期를 解消함과 아울러 아파트 人口가 增加하고 있는 오늘날 室內에서 簡單한 方法으로 풋마늘을 生産하는데 必要한 資料를 얻고자 하였다. 1) 萌芽率은 15±1℃區와 20±1℃區의 Hyponex와 水道물에서 瀋陽種(暖地型)이 瀋種 7日後에, 그리고 濟州種(暖地型)이 播種 21日後에 各各 100%를 나타내었다. 그러나 義城種(寒地型)은 15±1℃區에서 播種 7日後에 全혀 萌芽하지 않았고 21日後에 15±1℃區와 20±1℃區에서 各各 85% 및 95%의 萌芽率을 보였다. 2) 草長은 15±1℃區보다 20±1℃區에서, 그리고 水道물보다 Hyponex에서 더 크며 그의 伸長速度가 빨랐다. 瀋陽種은 15±1℃區와 20±1℃區의 Hyponex와 水道물에서 播種 35日後에 잎이 黃化하면서 草長의 伸長이 停止되었으나 濟州種과 義城種은 伸長을 繼績하였다. 瀋陽種은 다른 2品種에 比하여 草長이 顯著히 컸으며 伸長速度가 매우 빨랐다. 3) 播種 21日後의 葉數, 葉?徑, 葉重 및 葉?重은 15±1℃區보다 20±1℃區에서, 그리고 水道물보다 Hyponex에서 더 增加하였다. 供試 3品鍾中 瀋陽種이 各處理區에서 葉數가 顯著히 많고 葉重이 무서웠다. 義城種은 15±1℃區의 Hyponex와 水道물에서 葉伸長을 볼 수 없었다. 4) 比生長率(CGR)은 15±1℃區와 20±1℃區의 Hyponex와 水道물에서 瀋陽種과 濟州種은 播種7日後에, 그리고 義城種은 播種 14日後에 極大期를 나타낸 다음 漸次 減少하였다. 極大期의 比生長率은 15±1℃區보다 20±1℃區에서, 그리고 水도물보다 Hyponex에서 더 높았다. 5) 20±1℃區에서 CGR의 잎으로서 寄與率은 瀋陽種과 濟州種이 播種21日後까지 增加한 다음 漸次 減少하는 傾向을 보였으나 義城種은 繼績 增加하였고, 뿌리로의 寄與率은 3品種 모두 播種14日後부터 急激히 減少하였다. 6) 葉面積指數는 20±1℃區에서 3品種 모두 水道물보다 Hyponex에서 높았다. 播種28日後의 葉面積指數는 濟州種이 2.0 그리고 義城種이 1.0이었는데 比하여 瀋陽種은 4.0 以上이었다. 7) 本實驗의 어느 境遇에 있어서도 瀋陽種이 濟州種 및 義城種에 比하여 萌芽率가 빠르고 草長이 크고 葉收量이 많았으며, 15±1℃區보다 20±1℃區에서 그리고 水道물보다 Hyponex에서 生育이 良好하였다. 그리고 瀋陽種은 20±1℃區의 Hyponex와 水道물에서 播種後 14日이 經過하면 收穫이 可能하였다. The purpose of this study is to establish a production system for providing fresh leafy garlic in winter season and to obtain data for an easy method of indoor nutriculture of this plant, especially in apartment life. 1. Emergence rates in 15℃ and in 20℃ cultured by Hyponex and by tap water were 100% after 7 and 21 days from planting in Shenyang cultivar, a Southern ecotype, and in Cheju cultivar, a Southern ecotype respectively. Euisung cultivar, a northen ecotype, did not planting uner 15℃ until 7 days from planting, but emerged 85% and 95% after 21 days from planting under 15℃ and 20℃ conditions, respectively. 2. Plant lengths were higher in 20℃ and in Hyponex culture than in 15℃ and in tap water culture, respectively. Shenyang cultivar in 15℃ and 20℃ cultured by Hyponex and tap water ceased to eloongate the leaf and showed chlorosis after 35 days from planting, but Cheju and Euisung cultivars continued to elongate the leaf. The plant length of Shenyang cultivar was especially long as compared with other two cultivars and grew fast. 3. After 21 days from planting, leaf number, diameter of leaf sheath, leaf weight and weight of leaf sheath were higher in 20℃ and in Hyponex culture than in 15℃ and in tap water culture. respecively. Among three cultivars, Shenyang had much more leaves and heavy ones. 4. Comparative crop growth rate(CGR) showed at maximum after 7 days from planting in 15℃ and in 20℃ cultured by Hyponex and by tap water in Shenyang and Cheju cul-tivar while after 14 days from plamting in Euisung cultivar, then decreased gradually afterward. The CGR at maximum was higher in 20℃ and in Hyponex culture than in 15℃ and in tap water cul-ture, respectively. 5. The percentage of contribution of CGR to leaf were increased until 21 days from planting, then decreased gradually afterward in Shenyang and Cheju cultivars, but Euisung showed continu-ous increase. The percentage of contribution of CGR to root declined markedly after 14 days from planting in all three cultivars. 6. Leaf area index(LAI) were high in all three cultivars in 20℃ in Hyponex culture as compared with tap water culture. After 28 days from planting, LAI was 2.0 and 1.0 in Cheju and in Euisung cultivar respectively, comparing with above 4.0 in Shenyang cultivar. 7. In every conditions, Shenyang cultivar exceeded in emerging date, plant length and leaf produc-tion, and the growth was better in 20℃ and in Hyponex culture than in 15℃ and in tap water cul-ture, respectively. After 14 days from planting, Shenyang cultivar was possible to harvest in 20℃ cultured by Hyponex and by tap water.

면접조사를 통한 초등학생의 영양교육 실태 및 실천도 조사

오유진,이영미,김정현,안홍석,김정원,박혜련,서정숙,김경원,권오란,박혜경,이은주,성현이 대한지역사회영양학회 2008 대한지역사회영양학회지 Vol.13 No.4

This study investigated the experience and practice of elementary school students on nutrition education. The data were collected from 217 male and female students attending 5-6th grade elementary schools in Seoul and Kyunggi-Do from March to June 2007, interviewing face to face by a nutrition teacher and 3 interns of a nutrition teacher. The results were as follows: 86.5% of the subjects learned about ‘Table etiquette’, ‘Reasons for eating fruits and vegetables’ (78.7%), ‘Food waste and environment’ (72.3%), ‘Healthy snacks’ (55.7%), ‘Food sanitation’ (52.3%), ‘Food culture of foreign countries’ (48.1%). Nutrition education experience was significantly different by gender. A total of 43.5% boys responded that they never learned about ‘basic food preperation’ (p < 0.01). They had learned ‘Nutrients for body’ and ‘Food waste and environment’ in school, ‘Healthy weight loss’, ‘Food culture of foreign countries’, ‘Food circulation’ on television, Most content (‘Table etiquette’, ‘Simple cooking’, ‘Food sanitati n’, ‘Eating behaviors for health’, ‘Reasons for eating fruits and vegetables’, ‘Healthy snacks’) was learned from parents. The practice after nutrition education was higher in ‘Table etiquette’ (2.14), ‘Eating fruits and vegetables’ (2.07) than others compared with education experience. The most reason of non-practice on nutrition information was ‘Troublesome’. In ‘Nutrients for body’, a boy answered ‘Difficult for practice’ 20.0%, a girl answered ‘Difficult to understand’ 32.6%, showing a significant difference between the gender groups (p < 0.001). They remembered the ‘Nutrients for body’ (49.6%), ‘Food sanitation’ (44.5%) because of ‘important content’,‘Basic food preparation’ (40.6%), ‘Food culture of foreign countries’ (36.3%) because of ‘interesting content’, ‘Healthy weight loss’ (52.0%), ‘Eating behavior for health’ (44.5%) and ‘Healthy snacks’ (33.7%) because of ‘need for my health’.

지속적인 운동으로서의 골프가 아마추어 골퍼의 스트레스에 미치는 효과

오대성,송은섭,나정란 圓光大學校附設 生活體育硏究所 2001 生活體育硏究 Vol.11 No.-

This survey for the purpose of finding out the effects of Golf as a continuative exercise on the mental stress has made the following conclusion with the research results having examined the effects by using the stress measuring paper to the subjects of the amateur Golfers consisted of 183 (Male 98 and Female 85) in Chonbuk province. 1. The effects on the total stress levels as a continuative exercise shows that the male subjects (105.96±14.38) is higher than the female (104.05±11.49). 2. In the following stress levels the Golf has the effect showing that the male (19.72) is higher than the female (19.54) in the mental factor, and the male (35.74) is higher than the female (34.82) in the emotional and the anxiety factors. And it shows statistical significance (p=0.79). 3. The effects of Golf as a continuative exercise on the total stress levels according to the subjects' career shows that the group (108.03) whose career is more than 83 months is higher than the group (101.68) whose career is more than 49-82 months. 4. The effects of Golf as a continuative exercise on the mental stress in the following levels shows that the group (20.31) whose career is more than 83 months is higher than the group (18.71) whose career is more than 49-82 months in the mental factor, and the group (28.30) who career is more than 83 months is also higher than the group (25.76) whose career is more than 49-82 months in the physical and mental health factor respectively.

인도 무갈 시대 이슬람 성자(聖者) 세밀화(細密畵)의 기원과 발달

오정은 한국이슬람학회 2002 한국이슬람학회논총 Vol.12 No.-

This thesis aims to pioneer the study of Islamic art for the first time in Korea and thus introduce it to the Korean academic world. Although Islamic art is exquisite and splendid, it has been absolutely disregarded in Korea. Generally speaking, figural representation such as the depiction of human and animal forms has been prohibited by Islam. However, this research intends to support how much the Islamic painting of the Mughal Empire(1527-1825) flourished and bloomed, especially during the 100 years from Akbar, the Great Emperor to Shah Jahan, and specifically deals with the miniatures of Islamic saints. This thesis suggests the origin and development of the Islamic saints miniatures of tie Mughal court within the contexts of religion, art, history, and society. It was originated under the circumstances of Sufism and Persian paintings. Moreover, it developed under the royal patronage and protection of art followed by the influence of Sufi literature and European paintings. In conclusion, Islamic saints miniatures in the Mughal court are a wonderful example, proving the magnificence and great development of Islamic paintings. Although Islam currently still proscribes figural representation such as in the extreme case of iconoclasticism of Bamiyan Buddhist cave in Afganistan by Taleban, Islamic paintings do exist in beautiful features. In addition, it is hoped that this thesis is to establish a further foundation for Islamic art studies in Korea.

Vibrio vulnificus 박테리오 파아지의 특성

오양효,윤소겸,공은진,김민정,김영부,박영민 대한감염학회 1995 감염 Vol.27 No.5

목 적 : 이미 보고되어 있는 파아지들의 경우, 일반적인 형태, 숙주역과 몇 가지의 성질만 연구되어 있으므로 보다 상세한 특성에 대한 연구가 필요한 상태이다. 본 연구에서는 해양으로부터 분리한 V. vulnificus를 숙주균으로 하여 투명한 용균반을 형성하는 파아지를 분리해 낸 다음, 분리된 V. vulnificus 파아지의 특징을 연구하고자하였다. 방 법 : V. vulnificus 를 숙주균으로 하여 해산물로부터, 숙주균에 특이적인 파아지를 분리하고, 농축 정제과정을 거쳐 파이지입자를 순수분리하였다. 파아지의 형태를 전자현미경으로 관찰하였으며, 분리된 파아지의 숙주특이성을 조사하고, 파아지 입자의 물리적 특성을 검토하기 위해, 온도 안정성시험, pH 안정성 시험을 실시하였다. 파아지의 흡착율, 파아지의 흡착율에 미치는 무기염 이온의 영향, 온도의 영향과 pH의 영향을 관찰하였다. 파이지의 일단증식곡선을 구하였으며 토끼 면역과 교차 중화 시험, 파아지 핵산의 특성, 구조단백질의 특성을 조사하였다. 결 과 : 전자현미경관찰결과 본 연구에서 분리한 파아지는 두부와 미부를 가지는 형태로 미부에 꼬리판과 꼬리섬유를 가지고 있었다. 파아지의 물리적성질시험 결과 파아지는 50℃이하의 온도에서 안정하였으며 중성pH영역에서 안정하고 산성과 알칼리 영역에서는 활성을 잃었으며 자외선에는 35초 조사에 50% 정도 불활성화 되었다. 파아지는 약 65%의 흡착율을 나타내었으며 흡착에 ??, ??을 요구하였다. 파아지입자가 안정한 온도와 pH영역에서는 흡착에 영향을 받지 않았으며 일단증식시험 결과 108 PHU/ml의 파아지 입자를 생산하였다. 정제한 파아지를 항원으로 하여 토끼에 면역한 항혈청에 파아지가 중화되었으며 파아지 핵산은 이중나선 DNA였다. 파아지의 구조단백질은 SDS-PAGE polyacrylamide gel 전기영동 결과 2개의 밴드를 나타내었다. 그리고 Western blotting 결과 파아지의 전기영동 결과와 동일한 위치의 밴드에서 항원성을 나타내었다. 결 론 : 인체병원균으로 중요성이 인식되고 있는 V. vulnificus는 해산물의 위생과 국민건강에 직접적인 영향을 미칠 수 있는 세균으로 이에 대한 활발한 연구가 요구되는 실정이다. 파아지의 분리율은 숙주균의 분리율에 의존하므로 숙주균의 해수내 분포에 영향을 미친다고 추측되며, 파아지는 숙주균에 감염되어 숙주균을 용균시키므로 숙주균의 개체수를 조절하여 생태학적 측면에서 중요한 기능을 담당하는 것으로 여겨진다. Background : Vibrio vulnificus causes severe wound infection and life-threatening septicemia. In this study we present the characteristics of V. vulnificus bacteriophage and the basis of pathogenicity study of V. vulnificus related on bacteriophage. Methods : We isolated bacteriophage for V.vulnificus from marine products and examined its physiological and biochemical characteristics, and the ultrastructure by electron microscopy (TEM,SEM). And also, we investigated host ranges, temperature stability, pH stability, inactivation by UV irradiation, DNA isolation and analysis and structural protein analysis of the bacteriophage. Results : The adsorption rate of bacteriophage was above 80% and had a little influence at 10-45℃ and pH5-10. Isolated bacteriophage was used to produce antiserum against rabbits and its antigenicity was investigated by cross-neutralization. Western blot analysis showed the capsid protein of bacteriophage had antigenicity. The bacteriophage had double-strand DNA. In restriction analysis, the phage DNA was digested HinfI. The structural protein of phage showed two bands of 34.7kDa and 18.4kDa on SDS-PAGE. Conclusion : The specificity of bacteriophage may be due to the specific binding site that be possessed by host strain surface. Therefore, it seems that virulent bacteriophage controls the number of host strain and then takes a role on natural marine environment.

STS304와 S15C 이종마찰압접부의 접합계면 응력해석

오정국,차용훈,성백섭,박창언,김하식,김충환 한국공작기계학회 2002 한국생산제조학회지 Vol.11 No.3

Friction welding has many merits such as energy efficiency, simple processing, etc. but it is difficult to obtain good welding at the welded interfaces and heat affected zone. It is discovered that stress singularity exists at the interfaces and heat affected zone. The computer program based on boundary element method is utilized in this study. A mathematical model is implemented based on results from several experiments performed at and around the welded interfaces and heat affected zone of disimilar metal under static and dynamic loadings. This study is to investigate the characteristics of the deformation and fracture behavior around interfaces for friction welded materials under static tensile load. Also, the stress distribution at the tip of crack is analyzed by using BEM based on Kelvin's solution of 2-dimensional binding zone. The results of BEM are identical with those in case of considering interfaces of both heat affected zone. Also, stress singularity at the tip of interfaces appears when the elastic modulus ration is 1.07.