• 제목/요약/키워드: breaking test

검색결과 298건 처리시간 0.022초

직교배열법에 의한 칩절단특성 예측 (Pridiction of chip breakability by an orthogonal array method)

  • 이영문;양승한;권오진
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2001년도 춘계학술대회 논문집
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    • pp.1008-1011
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    • 2001
  • The purpose of this paper is to evaluate the chip breakability during turning using the experimental equation, which is developed by an orthogonal array method. The chip breaking index(CB), non-dimensional parameter is used in the evaluation of chip breakability. The analysis of variance(ANOVA)-test has been used to check the significance of cutting parameters. And using the result of ANOVA-test, the experimental equation of chip breakability, which consists of significant cutting parameters, has been developed.

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와이어 로프의 파단특성에 관한 실험적 연구 (An Experimental Study on the Fracture Characteristics of Wire Ropes)

  • 김종현;이근오;태순호
    • 한국안전학회지
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    • 제9권4호
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    • pp.3-10
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    • 1994
  • This study examines fracture characteristics of wire rope of 6$\times$37+FC 14mm B degree, Which has been widely used for the strength support for machinery, cranes and shipping. The examination Is based on the fellowing experimental conditions. Firstly, this study analyzes the effect of the strength of wlre rope. When number of broken wires is occuring at the level of 5%, 10% and 15% degree respectively in the following two cases:1) Case of broken down to each strand equally. 2) Case of broken down to one strand only. Secondly, this study analyzes the effect of corrosion on the strength of wire rope. Corrosion times are 72hours, 144hours and 216hours corrosion respectively under following conditions. 1) Case of only a corrosion without wire breaking. 2) Case of corrosion after 5% degree wire breaking to each strand equally. Some outcomes of these experiment are as follows. 1) From the of tension test, We can find that the ratio of strength reduction case of wire broke down to one strand concentrically is greater than that ratio case of broke down to each strand equally. 2) From the corrosion test, We can also find that the ratio of strength reduction case of corroded after 5% degree wire breaking to each strand equally Is greater than that ratio case of corroded without wire breaking. 3) After comparing theoretical fracture load of wires with experimental fracture load of wires, we can find the fracture load of the case of broken down to each strand equally is most similar to theoretical fracture load. 4) It is proposed that safety rules on wire rope in the Industrial safety and healthy labor of law have to change “breaking over 10% of number of wires in one strand of wire rope(excluded filler wire )”has to be replaced by“breaking over 10% of number of all wires in all strand of wire rope(excluded filler wire)”

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DC 비접지 급전계통 선택차단형 통합보호계전기 시뮬레이터 개발 및 알고리즘 테스트 (Development of a Simulator and Algorithm Test for Selective-breaking Integrated Protective Relay for Ungrounded DC Traction Power Supply System)

  • 안태풍;윤준석;정태영;김인웅;정호성
    • 전기학회논문지
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    • 제61권6호
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    • pp.899-904
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    • 2012
  • In recent years, a lot of research was done for earth fault protection in ungrounded dc power supply system. As a result, selective-breaking integrated protective relaying system is developed in progress and is currently field-testing are planned. Algorithm on a PC using PSCAD done a lot of testing before performing field tests, but in this study developed algorithms and functions needed to determine whether they were operating normally. Therefore, simulated system is similar to the actual situation was required and made. selective-breaking algorithm verification and validation was performed with simulator.

절연구간 조가선 FRP 절연봉의 절단사고 원인분석 (Analysis of Breaking Accident of FRP Insulator Rod installed in Dead Section)

  • 장동욱;이기원;김주락;박현준
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.1
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    • pp.502-505
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    • 2003
  • The accidnet of breaking insulator rod leads to inturruption of moving the subway. We investigate the analysis of analysis of breaking accident of FRP insulator rod installed in dead section for catenary feeding system. To analysis of accident reason, SEM is used to analysis microscopic struture on surface of cross section of broken FRP insulator rod. At the same time, we examine the chage of atomic amount on solace of accident insulator through EDX analysis. Also, the test for tensional breaking load is condoled to check the mechanical strength.

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직류고속도차단기의 소전류 차단 특성연구 (The Characteristic Study for Small Current Breaking of High Speed DC Circuit Breaker)

  • 민병훈;장우진;고인석
    • 대한전기학회논문지:전기기기및에너지변환시스템부문B
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    • 제55권8호
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    • pp.396-402
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    • 2006
  • Even the case DC circuit Breaker have good quality for interruption of high current like heavy load current, short-circuit current, the verification for small current breaking capability of circuit breaker should be performed. It comes from the reason DC small current breaking failure can be lead to break out second heavy fault condition and in the long run substation shutdown. In this paper, we can find the characteristics of DC small current and international test standard discription about small current breaking and one of the proper solution to get over it.

해저 석유개발을 위한 해양구조물의 기본 설계/해석 및 실험기법 개발 -해양구조물에 작용하는 파랑하중 산정에 관한 연구 (A Study on the Determination of Wave Load Acting on Offshore Structures)

  • 이근무
    • 한국해양공학회지
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    • 제14권1호
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    • pp.6-10
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    • 2000
  • In this paper various methods of determining of wave loads acting ofshore structures including impact load due to breaking wave are studied and corresponding model test was performed. In the theoretical approach wave load by nonbreaking wave and impact load by breaking wave is determined by Morrison's equation Goda's equation and impact wave equation, In the experimental approach wave load by nonbreaking wave acting on cylindrical pile used in offshore structures is determined by measuring the strain on a cylindrical pile and compared with theoretical calue. in the numerical approach impact load by breaking wave acting on a modeled cylindrical pile is calculated by usign ANSYS FEM program and compared with theoretical value. It is found that the experimental and numerical results are comparable to theoretical results, Thus the determination of wave load acting on offshore structures can be obtained by a proposed methods and it acceptable.

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빙해지역 일반 운항 및 쇄빙 운항 시의 빙하중 특성 비교 연구 (A Comparative Study on Ice Load Characteristics between General and Ice-breaking Operations in Ice-covered Waters)

  • 이민우;권용현;임채환;이탁기
    • 한국해양공학회지
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    • 제29권1호
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    • pp.28-33
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    • 2015
  • The icebreaking research vessel ARAON had her second ice trial in the Arctic Ocean from July 16 to August 12, 2010. In this study, the ice loads measured during the “general” operation and “ice breaking” operation in ice-covered waters were analyzed and compared. Whereas the “general” operation stands for the voyage in the water partially covered by ice, the “ice breaking” operation involved substantial ice floes for the ice breaking performance test. Based on the measured data, comparisons of the relationship between the ship speed and ice load, and between the locations of strain gauges and ice loads were investigated. Peak stresses higher than 20 MPa were found. The longitudinal and vertical correlations between the measurement location and ice load were analyzed, and the probability of peak stress was calculated. As a result, the probability function for higher ice loads during both operation modes was expressed in an exponential and power forms.

The Scanning Laser Source Technique for Detection of Surface-Breaking and Subsurface Defect

  • Sohn, Young-Hoon;Krishnaswamy, Sridhar
    • 비파괴검사학회지
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    • 제27권3호
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    • pp.246-254
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    • 2007
  • The scanning laser source (SLS) technique is a promising new laser ultrasonic tool for the detection of small surface-breaking defects. The SLS approach is based on monitoring the changes in laser-generated ultrasound as a laser source is scanned over a defect. Changes in amplitude and frequency content are observed for ultrasound generated by the laser over uniform and defective areas. The SLS technique uses a point or a short line-focused high-power laser beam which is swept across the test specimen surface and passes over surface-breaking or subsurface flaws. The ultrasonic signal that arrives at the Rayleigh wave speed is monitored as the SLS is scanned. It is found that the amplitude and frequency of the measured ultrasonic signal have specific variations when the laser source approaches, passes over and moves behind the defect. In this paper, the setup for SLS experiments with full B-scan capability is described and SLS signatures from small surface-breaking and subsurface flaws are discussed using a point or short line focused laser source.

FINECKER Plus를 이용한 도심지 진동제어 시공사례 (A Case Study on Vibration Control Method at Urban Area Using FINECKER Plus)

  • 민형동;정민수;박윤석;황의진;박준호
    • 화약ㆍ발파
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    • 제24권1호
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    • pp.49-56
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    • 2006
  • 도심지에서 폭약을 사용한 굴착공법은 진동 소음 비산 등으로 인한 안전상의 문제로 사용상 많은 제약이 따르고 있다 이러한 이유로 암파쇄굴착공법 (건교부, 2003)에 주로 쓰이는 FINECKER Plus(미진동파쇄기)의 사용이 점차 늘어나고 있다. 따라서 본 사례연구에서는 도심지 현장에서 진동을 제어하기 위해 FINECKER Plus를 적용하고, 신제품 360g 1본(本)과 기존제품 180g 2본(本)의 비교시험과 함께 무진동공법과 병행하여 시공성을 비교하였다. 신제품 360g의 파쇄효율 및 소음 진동수준에서는 대등한 정도로, 작업시간이 32% 감소하여 시공성 면에서는 뛰어난 결과를 얻었다 또한, FINECKER Plus의 굴착량은 $64.2m^3/$일로 무진동공법에 비해 7.7배 정도의 뛰어난 시공성을 나타내었다

무전해 (니켈/금) 도금 처리된 단분산 가교고분자 미립자의 기계적 물성 연구 (Study for Mechanical Properties of Electroless (Ni/Au) Plated Monodisperse Polymer Particles)

  • 김동옥;진정희;손원일;오석헌
    • 폴리머
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    • 제31권5호
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    • pp.410-416
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    • 2007
  • 무유화제중합으로 제조된 폴리(메틸 메타크릴레이트) (PMMA) 시드 고분자 미립자에 가교단량체인 HDDA (1,6-hexanediol diacrylate), triEGDMA [tri(ethylene glycol) dimethacrylate] 또는 triEGDMA와 EGDMA (ethylene glycol dimethacrylate)의 혼합액을 흡수시키고, 이를 중합하여 단분산 가교고분자 미립자를 제조할 시 1) 흡수된 가교단량체와 시드 고분자 미립자의 중량비(흡수율) 변화, 2) 가교단량체의 변화, 3) 무전해 니켈도금 및 4) 무전해 (니켈/금)도금에 따른 단분산 가교고분자 미립자의 기계적 물성인 탄성복원율, 압축탄성률, 파괴강도 및 파괴변형률의 변화를 MCT(micro compression test)를 사용하여 측정하였다. 이번 연구를 통해 가교단량체의 흡수율 증가는 가교고분자 미립자의 파괴강도에만 큰 영향을 미쳤으나, 가교고분자 미립자의 무전해 도금은 도금분체의 탄성복원율 및 파괴강도는 감소시키나, 파괴변형률의 경우에는 거의 영향을 미치지 않으며, 압축탄성률의 경우는 $K_{10}$$K_{20}$는 크게 증가시키나, $K_{30}$ 이후에는 거의 영향을 미치지 못함을 알 수 있었다.