• 제목/요약/키워드: Fasteners

검색결과 110건 처리시간 0.024초

A State-of-art of Experimental Research and Calculated Models of Dowel-type Timber Connections in Fire

  • Luo, Jing;He, Minjuan;Li, Zheng
    • International Journal of High-Rise Buildings
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    • 제10권4호
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    • pp.285-297
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    • 2021
  • Fire safety is one of the most significant issues for the design of mid-rise and high-rise timber structures. A large number of experimental tests were conducted during the last three decades to investigate the fire performance of the dowel-type timber connections. Many influenced parameters (e.g. the thickness of the side timber, the load ratio, the fasteners type etc.) were considered in those experiments. Relevant calculated models were proposed by previous researchers to estimate the fire resistance of the connections. In this study, a series of experimental programs of dowel-type connections in fire are collected. Then, empirical formulas proposed by EN 1995-1-2, Fire safety in timber buildings, and previous researchers are presented and analyzed. The accuracy of those formulas is checked by comparisons between the experimental data and estimated results. The collected experimental research and empirical formulas can be used as the reference for the fire design of dowel-type timber connections in the future.

Strength and Failure Mode Prediction of Mechanically Fastened Carbon/Epoxy Joints (탄소/에폭시 복합재료 구조물의 기계적 결합에 대한 강도 및 파손모드 예측)

  • 김기범;이미나;공창덕
    • Journal of the Korean Society of Propulsion Engineers
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    • 제1권1호
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    • pp.111-121
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    • 1997
  • An investigation was performed to study the predicting the joint strength of mechanical fasteners. Bearing failure is most important failure mode for designing joint. So in this study, the prediction method in consideration with bearing failure was chosen. In the proposed method, the characteristic length is combined with the Yamada-Sun failure criterion, Tsai-Hill failure criterion and characteristic length for Tension and Compression is determined from investigation. Especially the length of compression is determined from the "bearing failure test" that newly conceived to take bearing failure into consideration. The proposed prediction method was applied to quasi-isotropic carbon/epoxy joint showing net-tension and bearing failure experimentally. Good agreement was found between the predicted and experimental result for each joint geometry. geometry.

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A Study on the Adaptive Dress for the Disabled Ederly(2) - Nursing Facilities for the Ederly in Seoul and KyoungIn Area - (거동 불편 노인에 대한 기능성 의복 연구(2) - 서울, 경인 지역 노인 전문 요양 시설을 중심으로 -)

  • 홍나영;지윤영
    • The Research Journal of the Costume Culture
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    • 제8권6호
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    • pp.899-914
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    • 2000
  • The purpose of the study was to provide the actual data for designing adaptive dresses for the disabled elderly. In order to get the data, we had 3 parts of the procedure as follows ; 1. The survey of 205 nursing-care providers who take care of the disabled elderly in 1999. 2. Measuring 10 measurements of 80 disabled men and women each, 160 samples. 3. On the basis of data above, developing the adaptive dresses and doing the wearing-tests of those. The results are as follows ; 1. The most popular style for the disabled elderly in nursing facilities was non-collar pajama's. Specially, pajama style was needed for the disabled elderly being sick in bed, one-piece style was required for the disabled eldery with dementia. And the most desirable fabric function was a physiological comfortability. The most proper price required was about 20,000 won. 2. As Korean apparel industry use K.S. sizing system, we decided to use the same measurement to categorize the samples, bust and height. And according to the frequency in the size chart, we suggested the production size for the disabled eldery men and women. 3. After developing these adaptive dresses, the results of wearing-tests showed two kinds of problems. One was that of the sleeve length ; Actually, for the disabled elderly, the longer than the production size is the better for them. The other problem was revealed from subsidiay materials, fasteners.

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Seoul National University of Science and Technology (칼라 나사 검사를 위한 표면 영역 자동 검출)

  • Song, Tae-Hoon;Ha, Jong-Eun
    • The Journal of the Korea institute of electronic communication sciences
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    • 제11권1호
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    • pp.107-112
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    • 2016
  • Fastener is a very important component that is used in various areas in industry. Recently, various color fasteners are introduced. According to this, online inspection is required in this area. In this paper, an algorithm for the automatic extraction of the surface of color fastener using color information and dynamic programming is presented. The outer boundary of fastener is found using the difference of color that enables robust processing. The inner boundary of fastener is found by dynamic programming that uses the difference of brightness value within fixed area after converting image to polar coordinate. Experiments are done using the same parameters.

The Clothing Wearing Conditions of Dementia Inpatients (치매 환자복의 착의실태에 관한 연구)

  • Ryou, Eun-Jeong;Park, Hye-Won;Bae, Hyun-Suk
    • Journal of the Korean Home Economics Association
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    • 제44권4호
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    • pp.123-131
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    • 2006
  • The goal of this research was to investigate the actual wearing conditions of dementia inpatients in order to improve their clothes. The development of comfortable, functional and well-designed clothing for dementia inpatients can improve their clinical care environment and also provide dementia inpatients and their caregivers with a promoted quality of life. The data were collected through field research and interview survey on the inpatient's clothing being used at 10 dementia hospitals and 11 dementia nursing care facilities. The results were as follows, First, the uniforms of light dementia inpatients were the pajamas styles those of the general inpatient's uniforms. The uniforms of severe dementia inpatients were jump suits or pajamas styles. Second, the top styles of pajamas were shirts of front opening style with buttons, round neckline, full length sleeves and over armholes. Their bottoms were the pants of no opening style with elastic band and full length. The design of the jump suits had back and under opening styles with zippers. Third, dementia inpatient clothes have to be improved in the areas of sizing systems, structure for putting on and taking off, fasteners and open styles and clothing material, as well as the aesthetic approach.

Study on drilling of CFRP/Ti6Al4V stack with modified twist drills using acoustic emission technique

  • Prabukarthi, A.;Senthilkumar, M.;Krishnaraj, V.
    • Steel and Composite Structures
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    • 제21권3호
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    • pp.573-588
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    • 2016
  • Carbon Fiber Reinforced Plastic (CFRP) and Titanium Alloy (Ti6Al4V) stack, extensively used in aerospace structural components are assembled by fasteners and the holes are made using drilling process. Drilling of stack in one shot is a complicated process due to dissimilarity in the material properties. It is vital to have optimal machining condition and tool geometry for better hole quality and tool life. In this study the tool wear and hole quality were analysed by experimental analysis using three modified twist drills and online tool condition monitoring using Acoustics Emission (AE) sensor. Helix angle and point angle influence tool performance and cutting force. It was found that a tool geometry (TG1) with high helix angle of $35^{\circ}$ with low point angle $130^{\circ}$ results in reduction in thrust force of 150-500 N range but the TG2 also perform almost similar to TG1, but when compared with the AErms voltage generated during drilling it was found that progressive rise in voltage in TG1 is less with respect to TG2 which can be attributed to tool life. In process wear monitoring was done using crest factor as monitoring index. AErms voltage were measured and correlated with the performance of the drills.

Study of composite structure design and manufacturing for compliant legged robot (유연다리로봇 복합구조 설계 및 제작 기술 연구)

  • Choi, Rock-Hyun;Kang, Yoo-Na;Aulia, Widya;Lee, Gyoung-Jae;Lee, Dong-Ha;Kwon, Oh-Seok;Moon, Sang-Jun
    • 한국태양에너지학회:학술대회논문집
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    • 한국태양에너지학회 2012년도 춘계학술발표대회 논문집
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    • pp.410-413
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    • 2012
  • A traditional fabrication method is very difficult to make small robots using embedded sensors, actuators and connectors. Fortunately, Shape Deposition Manufacturing can provide an alternative method, and it has many benefits. Firstly, the weight of robot can be lighter, as it can be consisted of composite materials. Secondly, SDM can make simple robot structures because this approach does not need to use connectors and fasteners. Lastly, SDM gives stiffness and flexibility at the specific parts. Therefore, in this paper, we present a design of 3 segment legs organized by SDM, what the SDM approach is, and compare SDM method with 3 segment prototype legs which uses a traditional approach and made by DGIST.

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Evaluation of Stiffness Ratio of Wooden Mortise and Tenon Joint on Vertical Loading (수직 하중에 따른 목재 짜맞춤 접합부의 강성도 평가)

  • Park, Chun-Young;Lee, Jun-Jae;Kim, Gwang-Chul
    • Journal of the Korea Furniture Society
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    • 제23권3호
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    • pp.290-297
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    • 2012
  • Recently, interest in wooden construction have been growing by increasing needs and demands for eco-friendly and traditional wooden building(Hanok). Especially, Hanok has the technical development in manufacturing the mortise-tenon joint without fasteners(precut), so it could be called to modernization, industrialization and popularization. But the structural design and analysis of the structure were not regulated and had the difficulty to consider the variation of wooden member and to conduct the difficulty in the structural analysis and the design of the joint. In this study, the stiffness ratio of wooden mortise and tenon joint was evaluated according to the vertical loading, lintel and loading speed. The joint was distinguished in semi-rigid joint regardless of their factors. The stiffness ratio was 0.40 in vertical loading, 0.50 without vertical loading and 0.44 in horizontal loading with high speed. This study would be utilized to the structural analysis and design with structural analysis and design program.

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A Study of the Mechanical Properties of Patch-Bonded and Riveted Repairs on Cracked Al 6061-T6 alloy Structures

  • Yoon, Young-Ki;Kim, Guk-Gi;Yoon, Hi-Seak
    • International Journal of Precision Engineering and Manufacturing
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    • 제1권2호
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    • pp.55-60
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    • 2000
  • A comparison of Riveted and bonded repairs, bearing and net tension failures, and Al 6061-T6 plates is presented. The results are then compared with previous papers about bonded repairs on different patch materials and shapes. Aluminum alloys, including Al 6061-T6, have a face-centered-cubic crystal structure. Under normal circumstances, these types of crystal structures do not exhibit cleavage fractures even at very low temperatures. In aluminum-base structures, the cracked plate structures are frequently repaired using mechanical fasteners-either rivets of bolts- even though patch-bonding techniques are applied to repair and reinforce the structure. Static test results indicate that the riveted repairs are affected by the position of the rivers. When using the same size of patch, the bonded repair technique is stronger; the rate of elongation is also increased. Form FEM analysis, it is revealed the origin of patch debonding in patch-bonded structures is the edge of the patch along to the tensile strength.

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A study of preferences and satisfaction levels in maternity and nursing brassieres (임산부 및 수유부 전용 브래지어 실태조사와 만족도 연구)

  • Jang, Mi-Na;Kim, Dong-Eun
    • The Research Journal of the Costume Culture
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    • 제25권4호
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    • pp.419-432
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    • 2017
  • The purpose of this study was to investigate preferences and satisfaction levels in maternity and nursing brassiere. A questionnaire was conducted on 302 women from their 20s to 40s who had breastfeeding experience. The questionnaire included questions on participant demographics, purchase behavior, and design preference and satisfaction levels. The majority(98.0%) of the participants had had experience using maternity/nursing brassieres. More than 90% of the participants agreed with the need for maternity/nursing brassieres distinct from regular ones. Shopping online was the most common means of purchasing them. The most and second-most owned fastener types were the detachable shoulder belt type and inside-cup type, respectively. The most selected reason for purchasing or wearing a maternity/nursing brassiere was the convenience of donning and doffing the brassiere during breastfeeding. Participants had lower satisfaction levels with how well maternity/nursing brassieres support and center the breasts, and with the variety of designs available on the market. Respondents indicated that fasteners for breastfeeding should be developed to provide comfort and convenience for breastfeeding. Wearing comfort was reported as the most important factor in purchasing selection, both during the pregnancy and breastfeeding periods. No-wire, back closure, full-cup, U-shape wing, and skin color were the most preferred design styles.