• 제목/요약/키워드: nut

검색결과 541건 처리시간 0.028초

박용엔진 실린더 커버 스터드의 구조거동 분석 (Structural Behavior of the Cylinder Cover Stud of Marine Diesel Engine)

  • 김병주;이재옥;박진수;김세락
    • 한국마린엔지니어링학회:학술대회논문집
    • /
    • 한국마린엔지니어링학회 2006년도 전기학술대회논문집
    • /
    • pp.267-268
    • /
    • 2006
  • The cylinder cover stud of low-speed marine diesel engine is more than just a stud. It is a large structural element occasionally weighing over 200 kg used for assembling the combustion chamber components. Therefore, to understand the structural behavior of the stud and design it safely is quite important considering a catastrophic failure which can be arisen from an inadequate use of it. In this paper, the analysis results of the structural behavior of the stud is introduced. Strain measurement results compared with FE analysis results are summarized. The results showed that 1) the stud stress increased with engine operating load, 2) the maximum stress amplitude was about 10 MPa which is far smaller than the stud's fatigue strength of 61 MPa, 3) the stress ratio is higher than 0.9 and the stud's load factor is about 20 %, and 4) about 7 % of initial pressure tightening load was reduced while changing to a nut tightened condition.

  • PDF

저항운동치료 처방에 관한 연구 (A Study of Resistive Therapeutic Exercise Prescription)

  • 배성수;김태숙;김은주
    • The Journal of Korean Physical Therapy
    • /
    • 제11권1호
    • /
    • pp.149-156
    • /
    • 1999
  • Resistive therapeutic exercise prescription goal is to improve functional performance and capabilities through the development of increased muscular strengh endurance or power. Resistance can be applied to either dynamic or static muscle contractions. Resistive therapeutic exorcise can be carried nut concentrically, eccentrically, isometrically, isokinetically. Neurodevelopmental treatment has not resistive therapeutic exercise concept. But proprioceptive neuromuscular facilitate techniques have resistive therapeutic exercise concept with pattens and techniques. It is aid muscle contraction, motor control and increase strength. Manual muscle testing will help the therapist establish a qualitative and quantitative baseline level of strength. Manual resistance maybe applied a against controlled lengthening contraction re static contraction of a muscle. A repetition maximum is not easy to calculate and is not the most accurate method available today to measure strength before of after a resistive therapeutic exercise program. Oddvar Holten Diagram is essy to calculate and is the most accurate method available today to measure strength before of after a resistive therapeutic exercise program. Plyometric training emphasize the development of muscular power and coordination. Quick bursts of force in functional movement patterns are often necessary of a patient is to return to high-demand occupational, recreational or sports related activities.

  • PDF

연마 브러시 접촉력 산출을 위한 비선형 강건제어기 실험 (Experiments on Robust Nonlinear Control for Brush Contact Force Estimation)

  • 이병수
    • 한국정밀공학회지
    • /
    • 제27권3호
    • /
    • pp.41-49
    • /
    • 2010
  • Two promising control candidates have been selected to test the sinusoidal reference tracking performance for a brush-type polishing machine having strong nonlinearities and disturbances. The controlled target system is an oscillating mechanism consisting of a common positioning stage of one degree-of-freedom with a screw and a ball nut driven by a servo motor those can be obtained commercially. Beside the strong nonlinearity such as stick-slip friction, the periodic contact of the polishing brush and the work piece adds an external disturbance. Selected control candidates are a Sliding Mode Control (SMC) and a variant of a feedback linearization control called Smooth Robust Nonlinear Control (SRNC). A SMC and SRNC are selected since they have good theoretical backgrounds, are suitable to be implemented in a digital environment and show good disturbance and modeling uncertainty rejection performance. It should be also noted that SRNC has a nobel approach in that it uses the position information to compensate the stickslip friction. For both controllers analytical and experimental studies have been conducted to show control design approaches and to compare the performance against the strong nonlinearity and the disturbances.

光陽 表層 海水中의 重金屬 含量 (Heavy Metals in the Surface Waters of Kwangyang Bay During 1983-84)

  • 이수형;김은수
    • 한국해양학회지
    • /
    • 제21권3호
    • /
    • pp.125-130
    • /
    • 1986
  • 1983년 1월부터 1984년 12월까지 광양만의 20개 정점 표층에서 Cu, Pb, Zn 등 의 중금속 합량을 16회에 걸쳐 조사하였다. 전 조사기간을 통한 각 원소의 변동범 위와 평균농도는 Cu:〈0.03-2.68$\mu\textrm{g}$/$\ell$, 1.08$\mu\textrm{g}$/$\ell$, Pb:〈0.03-7.19$\mu\textrm{g}$/$\ell$, 0.76$\mu\textrm{g}$/$\ell$, Zn:0.3-23.1$\mu\textrm{g}$/$\ell$, 5.6$\mu\textrm{g}$/$\ell$였다. 광양만의 중금속 농도는 전반적으로 낮았으나 일반 해역보다는 수어천 하구 및 섬진강 하구등 담수의 영향을 많이 받는 해역에서 다소 높은 농도를 나타내었다. 통계학적 상관관계를 보면 Cu, Pb, Zn는 상호간은 물론 SS와 COD와도 유의성 있는 상관관계를 나타내었다.

  • PDF

스틸 휠 굽힘 모멘트 내구시험의 내구신뢰성 개선에 대한 연구 - 스틸 휠 접촉면의 프랫팅 제거 - (A Study for Improvement of Cornering Fatigue Test by Eliminating a Fretting Effect on Steel Wheel to enhance Durability and Reliability)

  • 정수식;정원욱;유연상;강우종;김대성;권일기
    • 대한기계학회:학술대회논문집
    • /
    • 대한기계학회 2008년도 추계학술대회A
    • /
    • pp.1326-1330
    • /
    • 2008
  • The failure mode of steel road wheels in a vehicle is cracks from ventilation hole through to contact plane on steel wheel's disc plate. But a number of cracks of Cornering Fatigue Limit Test is on contact plane near to wheel nut mounting area, even though it's satisfied with specified cycles. So this paper searches out causes to improve durability and reliability of C.F.T by uni-axial bending moment test. The verified cause is a "fretting" on contact area of steel wheel. In result, this paper suggests a solution to prevent a fretting by inserting a damping shim, 0.7mm between steel wheel contact areas. Therefore this paper makes it possible to move crack position of C.F.T in steel wheel from contact plane to vehicle's failure mode.

  • PDF

조정성과 내구성 향상을 위한 타이어 측벽형상 최적설계 (Optimal Design of Tire Sidewall Contours for Improving Maneuverability and Durability)

  • 조진래;정현성;이홍우;김남전;김기운
    • 대한기계학회논문집A
    • /
    • 제25권10호
    • /
    • pp.1636-1643
    • /
    • 2001
  • Automobile maneuverability and tire durability are significantly influenced by the sidewall tire contour. In order to improve these tire performances, it is very important far one to determine a sidewall contour producing the ideal tension and strain-energy distributions. However, these requirements can nut be simultaneously achieved by conventional non-interactive multi-objective optimization methods based on mathematical programming, because these exhibit the conflicting behavior each other, with respect lo the sidewall contour. Therefore, we execute the tire contour optimization fur improving the maneuverability and the tire durability using satisficing trade-off method.

원자력발전소에서 사용중인 모터구동밸브 스템 윤활유의 성능 비교 분석 (A comparison analysis of the stem lubricant performance for motor operated valve used in nuclear power plants)

  • Kim, Dae-Woong;Kim, Yang-Seok;Park, Chi Young;Lee, Sang Guk
    • 한국압력기기공학회 논문집
    • /
    • 제11권2호
    • /
    • pp.6-12
    • /
    • 2015
  • In this study, the performance test was carried out under various operation conditions targeting four representing types of lubricant which are mostly used in nuclear power plants, and mutually compared the characteristic and performance of lubricant. Especially, introducing the concept of the thread friction coefficient (hereinafter, TFC), which makes the friction relation between the stem nut and stem screw dimensionless. The test was performed to compare the lubricant performance for the four kinds of lubricant (Texaco, Alvania, Mobilux, MOVLL). In a test of the room temperature stem, the TFC of MOV Long Life shows the lowest value, next to Alvania EP2, Texaco EP2, and Mobilux EP0 in that order. And in a test of the high temperature stem, the TFC of Texaco EP2 shows the lowest, next to MOV Long Life, Alvania EP2, and Mobilux EP0 in that order. From the test result of the aging condition, three types of lubricant (MOV LL, Texaco EP2, Alvania EP2) show similar patterns up to 36 months, but in 60 months, the TFC of lubricant are increased rapidly.

황색 및 적색계 천연염료의 염색성에 관한 연구(1) (A Study on the Dyeing Properties of Yellow and Red Natural Dyes(1))

  • 신영준
    • 한국의상디자인학회지
    • /
    • 제17권2호
    • /
    • pp.45-61
    • /
    • 2015
  • In order to analysis on color difference of natural dyes, I have dyed Hanji, cotton, silk fabric and exposed them to carbon arc light. The results of experiment have been analysed by wavelength of maximum absorption, amounts of dye uptake, color difference, Hunter's value and Munsell's value. Gardenia Jasminoides is monogenetic dye, but it gained darker color by pre-mordanting method used Al mordant agent and greenish yellow color by Fe mordant agent. whereas Curcuma, an Amur cork, and bud of pagoda tree are shown as greenish yellow color, and A barberry root, Betel nut, and Rhubarb are shown as reddish yellow color. these gained khaki colored dyed fabric by Fe mordanting. In addition, Sappan wood showed great result in pre-mordanting. Especially, it gained dark red color by Al pre-mordanting. The pink color was shown by post-mordanting. and Logwood showed great dyeing result in Hanji and cotton better than silk. Specially pre-mordanting was effective. Hanji and cotton showed greenish blue color by Al pre-mordanting, and silk showed brown color.

  • PDF

황색 및 적색계 천연염료의 염색성에 관한 연구(2) (A Study on the Dyeing Properties of Yellow and Red Natural Dyes(2))

  • 신영준
    • 한국의상디자인학회지
    • /
    • 제18권4호
    • /
    • pp.77-86
    • /
    • 2016
  • In order to analysis on color difference of natural dyes, I have dyed Hanji, cotton, silk fabric and exposed them to carbon arc light. The results of experiment have been analysed by Munsell's value, and compared the difference of colors which were recognized visually. Gardenia Jasminoides is monogenetic dye, but it gained darker color by pre-mordanting method used aluminum mordant agent and greenish yellow color by ferric mordant agent. whereas Curcuma, an Amur cork, and bud of pagoda tree are shown as greenish yellow color, and A barberry root, Betel nut, and Rhubarb are shown as reddish yellow color. these gained khaki colored dyed fabric by ferric mordanting. In addition, Sappan wood showed great result in pre-mordanting. Especially, it gained dark red color by aluminum pre-mordanting. The pink color was shown by post-mordanting. and Logwood showed great dyeing result in Hanji and cotton better than silk. Specially pre-mordanting was effective. Hanji and cotton showed greenish blue color by aluminum pre-mordanting, and silk showed brown color. However the color, which was recognized visually, differed from colorimeter sometimes. Therefore, such color table might be necessary for the natural dyeing.

  • PDF

상용차용 액셀 케이싱의 너트부 용접공정 자동화 시스템 개발 (Development about Welding-process Automatic System on the department of Axle Casing Nut for Commercial Vehicle)

  • 김재열;유신;오성민;장종훈
    • 한국정밀공학회:학술대회논문집
    • /
    • 한국정밀공학회 1996년도 추계학술대회 논문집
    • /
    • pp.810-814
    • /
    • 1996
  • The purpose of this exclusive welding-machine process using the welding Torch-rotation form is to develop a mechanism which can solve the problem of twisted welding wires and cables. The technique was developed by revising the torch position and smooth controlling of both the formal and reverse rotation. Some of the advantages of using the Torch-rotation form over the Work-rotation technique are the practical uses of increased work space and link work with the automation system of the plant. Using this welding machine process, It is possible to design a specific tool in order to solve the implemental problem. And I produced a control plate which can manipulate the progress of the entire process at the work place. Even if another kind of axle casing's welding work is used this process can be utilized if the fixed tip and work is produced and changed. The development if this exclusive welding-machine could reduce the manpower of skilled welding labor and after considerable analysis, this machine was found to increase productivity and better quality product in comparison to the handmade product.

  • PDF