• Title/Summary/Keyword: Movable Parts

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Analysis of large deformation and fatigue life of fabric braided composite hose subjected to cyclic loading

  • Cho, J.R.;Kim, Y.H.
    • Steel and Composite Structures
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    • v.21 no.4
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    • pp.949-962
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    • 2016
  • The braking hose in the automotive hydraulic braking system exhibits the complicated anisotropic large deformation while its movable end is moving along the cyclic path according to the steering and bump/rebound motions of vehicle. The complicated large deformation may cause not only the interference with other adjacent automotive parts but also the durability problem resulting in the fatal microcraking. In this regard, the design of high-durable braking hose with the interference-free layout becomes a hot issue in the automotive industry. However, since it has been traditionally relied on the cost-/time-consuming trial and error experiments, the cost- and time-effective optimum design method that can replace the experiment is highly desirable. Meanwhile, the hose deformed configuration and fatigue life are different for different hose cyclic paths, so that their characteristic investigation becomes an important preliminary research subject. As a preliminary step for developing the optimum design methodology, we in this study investigate the hose deformed configuration and the fatigue life for four representative hose cyclic paths.

Dressing Poses in Relation to Clothing Thermal Insulation

  • Li, Jun;Zhang, Weiyuan;Liu, Yan
    • Fashion & Textile Research Journal
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    • v.4 no.6
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    • pp.544-549
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    • 2002
  • By the movable thermal manikin developed by China Dong Hua university, the laws of clothing thermal insulation influenced by dressing poses are studied. It is found that $I_a$ on nude thermal manikin has no relation to testing pose as a whole (notable level is 5%), while the change of testing pose influences $I_a$ value on parts of body obviously. The testing result $I_{cle}$ on clothed thermal manikin has relation to testing pose. The $I_{cle}$ value of the whole body in seated pose decreases 20 percent compared with that in standing pose (notable level is 1%). In view of heat transmission theory, the reasons are pointed out based on the knowledge of heat transmission.

A Study on the Standard Durable Years of Pipe Framed Greenhouses (파이프 골조 온실 구조물의 표준내용연수 연구)

  • 남상운
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.43 no.1
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    • pp.96-101
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    • 2001
  • In designing the greenhouse structures, snow and wind loads must be estimated on the basis of the probability of occurrence of snow or wind storms of a given intensity. The recurrence interval chosen depends on the standard durable years and safety factors of the greenhouse. This study was carried out to find the standard durable years of pipe framed greenhouses. Bend test for metallic materials was conducted on samples of galvanized steel pipes being used in greenhouse frames. A secular change of collapse loads and flexural rigidity for galvanized steel pipes were analyzed with the parts buried in the ground and exposed in the atmosphere. From those experimental results and corrosion rate of galvanized film, the standard durable years for pipe framed greenhouses are estimated as follows ; the small scale pipe houses of movable type is 7∼8 years and the large scale pipe houses of fixed type is 14∼15 years.

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Rudder Gap Cavitation Suppression Using Gap Flow Blocking Devices

  • Oh, Jung-Keun;Lee, Chang-Min;Lee, Hee-Bum;Rhee, Shin-Hyung;Suh, Jung-Chun;Kim, Hyo-Chul
    • Journal of Ship and Ocean Technology
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    • v.12 no.4
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    • pp.20-31
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    • 2008
  • Development of rudder gap flow blocking device for lift augmentation and cavitation suppression is presented. In order to verify the performance of this device, cavitation visualization and surface pressure measurements were carried out in a cavitation tunnel. Numerical simulations were conducted using a computational fluid dynamics code for more rigorous verification. The new rudder system is equipped with cam devices, which effectively close the gap between the horn/pintle and movable wing parts. The experimental and computational results show that the proposed rudder system is superior to the conventional rudder systems in terms of the lift augmentation and cavitation suppression.

A review of Safety standards for insulating materials in overhead contact line (전차선로 절연물의 안전성 평가기준 검토)

  • Lee, Bong-Jae;Jung, Ho-Sung;Lee, Ki-Won;Kwon, Sam-Young;Lee, Ki-Seung;Cho, Ho-Ryung
    • Proceedings of the KSR Conference
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    • 2008.11b
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    • pp.269-274
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    • 2008
  • The Seoul subway is acting the center of public transportation after the opening of the first line on August 15, 1974. and the subway line of the DC traction system is running and building to the ninth line. However, the main insulation parts used in overhead contact line are now imported from overseas products. Therefore, this paper considers domestic manufacture technology, supply easiness and economic effectiveness of insulation products and reviews the safety of support insulator used in rigid conductor line, stem insulator used in movable bracket and AC/DC different phase section insulator that localization development is necessary.

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Reliability Improvement of an Auto Transfer Switch (자동 전환 개폐기의 신뢰성 향상에 관한 연구)

  • Cho, Hyung Jun;Baek, Jung-Ho;Yeu, Bong-Ki;Kang, Tae-Seok;Kim, Kil-Sou;Yang, Il Young;Yoo, Hwan Hee;Yu, Sang Woo;Kim, Yong Soo
    • Journal of Applied Reliability
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    • v.16 no.2
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    • pp.162-170
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    • 2016
  • Purpose: The purpose of this study was to analyze the failure modes of an auto transfer switch (ATS), determine the most common failure mechanisms, and iterate the design to improve reliability. Methods: We carried out failure mode and effect analysis (FMEA) to determine the failure modes and mechanisms. We identified the parts or modules that required improvement via two-stage quality function deployment based on FMEA, and improvements to reliability were monitored using the Gomperz growth model. Results: The main failure modes of the ATS were damage to, and deformation of, the stator / movable element due to repetitive movements. Five iterations of design modification were carried out, and the mean time to failure (MTTF) increased to 14,539 cycles, corresponding to 85% of the target MTTF. The Gompertz growth model indicates that the 10th iteration of design modification is expected to achieve the target MTTF. Conclusion: We improved the reliability of mechanical parts via failure mode analysis, and characterized the iterative improvements in the MTTF using the Gompertz growth model.

Numerical Analysis of Wave-induced Motion of Floating Pendulor Wave Energy Converter (부유식 진자형 파력발전 장치의 파랑운동 수치해석)

  • Nam, Bo-Woo;Hong, Sa-Young;Kim, Ki-Bum;Park, Ji-Yong;Shin, Seung-Ho
    • Journal of Ocean Engineering and Technology
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    • v.25 no.4
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    • pp.28-35
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    • 2011
  • In this paper, the wave-induced motion characteristics of a floating pendulor are investigated numerically. A floating pendulor is a movable-body-type wave energy converter. This device consists of three main parts (floater, pendulum, and damping plates). In order to obtain the hydrodynamic coefficients and wave exciting forces acting on floating bodies, a higher-order boundary element method (HOBEM) using a wave Green function is applied to the present problems. The hinged motion of a pendulum is simulated by applying the penalty method. In order to obtain a more realistic motion response for a pendulor, numerical body damping is included. First, the wave force and motion characteristics of just a floater are observed with respect to different shape parameters. Then, a coupled analysis of a floater, pendulum, and damping plates is carried out. The relative pitch velocity and wave forces acting on the floating pendulor are compared with those of a fixed pendulor.

A Study on the Design and Power Performance of a Variable Photovoltaic Lightshelf Mounted on the Windows (창호거치 태양광발전 가변형광선반 설계 및 기초적 발전성능에 관한 연구)

  • Chung, Yu-Gun
    • KIEAE Journal
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    • v.13 no.6
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    • pp.105-111
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    • 2013
  • This study aims to suggest the PV lightshelf and to evaluate the power performance of the photovoltaic systems easily mounted on the windows. For the study, the suggested systems consist of two parts as fixed and movable PV modules. Also, tempered glass and polycarbonate are used on the surface protection materials for solar cells of PV lightshelf. By using polycarbonate, the weight of PV lightshelf is lighter about 20%. The field tests are performed for five days by using real size models. The voltage, current and electric powers are measured as basic performances of PV lightshelf. Also, the irradiation, brightness and module surface temperature are measured as outside conditions. As results, the power performance of tempered glass PV lightshelf shows about 11(%) higher thant that of polycarbonate PV lightshelf. And the power performance shows about 5(%) higher in a horizontal system. This results could be used to develop the effective PV lightshelf in next study.

Improvement Trend of a Humanoid Robot Platform HUBO2+ (휴머노이드 로봇플랫폼 HUBO2+의 기술 개선 추이)

  • Lim, Jeongsoo;Heo, Jungwoo;Lee, Jungho;Bae, Hyoin;Oh, Jun-Ho
    • Journal of Institute of Control, Robotics and Systems
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    • v.20 no.3
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    • pp.356-363
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    • 2014
  • This paper covers improvement of the humanoid robot platform HUBO2, known as the HUBO2+. As a necessity of the growth of the humanoid platform, a robust, reliable and user friendly platform is needed. From this standpoint, HUBO2+ is the most improved humanoid robot platform in the HUBO series. The mechanical design has been changed to increase the movable range and to stop joint compulsion. Additionally, all of the electrical parts are re-designed to be un-breakable in an unexpected situation. A smart power controller with robot status check panel is attached on the back. Additionally, a diagnosis tool, the HUBO-i, has been developed. Moreover, each joint motor controller of HUBO2+ has a Protection Function and a PODO system is provided for handling the robot easily.

A Study on the Design Characteristics of Steel Frame in Modern Architecture (근대건축과 철구조의 디자인특성에 관한 연구)

  • 이정욱
    • Korean Institute of Interior Design Journal
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    • no.6
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    • pp.53-62
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    • 1995
  • This research aims at proving the fact that the forms, spaces and many other design concepts of Modernism are much related with the changes of materials, struc-tures, and the way of construction as well as the idealis-tic and aesthestic things through the history of steel, one of the most important materials of the style. The meaning steel has in the modern architecture can be studied in the structure and industrial production system. 1) Steel frame broadened the range of understanding the space and created the new form through the skeleton/skin structure by reinterpreting the existing space fac-tors while it was being adopted to the architecture. Walls could be freed from the traditional function of bear-ing wall and roofs gave the transparancy to the interior by being linked with the glass. Posts lost the function which confines the space in the frame of the grid system and gave the flexibility to the interior due to the economical materials. These changes made the movable partition, screen with various materials and the system furniture which divides the space more important. 2) In the aspect of the industrialized architecture, it be-came the moment that the most of the archtectural com-posing parts were in mass production as they were standarized, high qualified, and generalized by the indus-trial characteristics of steel, and the specialization of structure and cladding, but the neither of the efforts to make the building itself by mass production or to standarize it was fulfilled. The high-tech architecture which borrows its archtectural manifestation from the high technology, however, is consistently paying efforts on such industrialization.

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