베어링 마모시험을 이용한 진동신호의 통계적 파라미터 특성연구

전오성,황철호,윤병옥,은희준,Jun, Oh-Sung,Hwang, Cheol-Ho,Yoon, Byung-Ok,Eun, Hee-Joon 한국음향학회 1989 韓國音響學會誌 Vol.8 No.1

RMS, Kurtosis, Crest factor, Probability of exceedance와 Probability density function 등의 통계적 파라미터를 선정하여 베어링의 사용조건과 결함진전에 따른 변화특성을 조사하였다. 이를 위해 4볼 시험기에서 하중, 회전수 및 시간을 변화시키면서 실험하여 진동신호를 수집하고, 이를 A/D변환시킨 후 디지털 필터링하여 주파수 대역별 통계적 파라미터 값을 계산하였다. 실험결과, 하중이나 회전수와 같은 운전조건이 변화하는 경우 RMS의 값은 운전조건 변화에 따라 변하지만 Kurtosis 등의 통계적 파라미터들은 운전조건과 무관하게 steady한 결과를 나타내었다. 또한 통계적 파라미터와 시간과의 상관관계에 대한 실험으로부터 통계적 파라미터들을 결함의 진전 상태를 나타내는 파라미터로 사용할 수 있음을 확인하였으며, 따라서 파손방지를 위한 예측지표로서 이들 통계적 파라미터를 이용할 수 있을것으로 판단되었다. This paper is concerned with the characteristics on the statistical parameters of vibration signal from bearing with changing its operating conditions as well as the spreading of faults. The rms, Kurtosis, crest factor, probability of exceedance and probability density function have been chose as the statistical parameters. To characterize of each, vibration signals have been recorded from four ball tester at different loads, operation speeds and time. The values of the statistical parameters for each frequency band have been calculated after A/D conversion and digital filtering of the recorded signals. It has been found that unlike rms values the statistical parameters such as Kurtosis etc. are almost unchanging with the change of the operating conditions such as load and speed. This suggests that the statistical parameters may be used for determining the development of faults independent of the operating conditions. In fact, the statistical parameters deviate considerably from their respective normal values when the faults developed under load conditions in the samples, conforming the suggestion.

정밀 축진동 측정에 사용되는 비접촉식 진동센서의 측정오차

전오성,김동혁,최병천 한국소음진동공학회 1991 소음 진동 Vol.1 No.2

When non-contact type vibration probes are used for the precision measurement of shaft vibration, they can induce the measurement errors due to the shaft curvature since they have been calibrated for the flat plate. In this study the errors due to the shaft radius and the misalignment between the shaft and probe centerlines are analyzed, and an in-situ calibration tool, which can be conveniently used for calibration independent of the shaft curvature and material, is introduced.

각가속도와 마찰 영향하의 회전요소 운동해석

전오성 전주대학교 공학연구소 1996 전주대학교 공학기술종합연구소 학술논문집 Vol.2 No.2

The motion of a rigid body (upper rotor) pin-jointed at a point on a base body (base rotor) is analyzed. The base rotor is strongly accelerated both angularly and along the axis perpendicular to the rotation plane. Since the motion of the assembly occurs during very short time, it is very hard to assess the motion experimentally. To analyze the motion, the equations of motion are made and calculated numerically. The friction between the upper and the base rotor surfaces is considered, and the effect is discussed.

경량전철의 소음전파 특성

전오성 전주대학교 공학기술종합연구소 1998 전주대학교 공학기술종합연구소 학술논문집 Vol.4 No.2

Noise from the light rail transit is composed of the rolling noise emitted from the space between vehicle bottom and rail and the radiation noise due to the vibration of the steel or concrete structure guiding the moving light rail transit. Model of noise propagation from the light rail transit is explained based on the experimental data. The rolling noise from the moving light rail transit and the radiation noise from the vibrating concrete structure with PC beams are simulated using the propagation model.

개폐균열을 갖는 회전체에서의 응력확대계수 계산

전오성,이종원,엄윤용,은희준 대한기계학회 1991 대한기계학회논문집 Vol.15 No.5

본 연구에서는 파괴역학적 개념을 도입하여 수평 회전체에 존재하는 횡방향 개폐균열의 모형을 설명하고 균열거동을 분석하였으며, 균열의 깊이, 회전속도 및 회 전방향에 따른 균열선단에서의 응력확대 계수를 계산하고 그 특성을 분석하였다.

쇼핑몰 신뢰도 분석을 통한 친환경 농산물 전자상거래 활성화에 관한 연구

전오성,이상준,권귀영 한국지식정보기술학회 2011 한국지식정보기술학회 논문지 Vol.6 No.6

Desire for safety and health on agricultural produce became an overall social phenomenon. Demand for environment-friendly agricultural produce is constantly on the rise. The volume of production is on the rapid increase as well with the government’s active support for eco-friendly agriculture. The pace of growth in e-commerce transactions of eco-friendly agricultural products tends to be relatively slow because of complexity of distribution stages, imbalance of supply and demand, poor delivery system, high prices, and consumers’ low awareness on reliability. In this paper we empirically researched that e-commerce transactions will be promoted if consumers’ satisfaction levels can be high by increasing the reliability on major component elements like producers, certification organizations, and distributors.

단위 충격 응답함수를 이용한 원형관 시스템의 누출감지 연구

전오성,윤병옥,김창호 한국소음진동공학회 1994 소음 진동 Vol.4 No.3

A method of the leak detection from the pipe system by using accelerometer is proposed. The signal detected from accelerometer is proved experimentally to be a dispersive wave. Based on the experiments, a method using the narrow band pass filter and the unit impulse response function is analyzed. The method uses the characteristics of the unit impulse response function, that the function is available evenin the narrow band signal because, unlike the cross correlation, it is normalized by the auto spectrum. The accelerometer is quite easier to use than the hydrophone in adapting to the pipe system.

기계진동 진단 기초

전오성 한국소음진동공학회 2011 한국소음진동공학회 강습회 Vol.2011 No.4

회전체의 비틀림 고유진동 해석

전오성,김정태 대한기계학회 1995 대한기계학회논문집 Vol.19 No.6

A method to estimate the torsional critical speed for practical rotors has been developed in this study. First, the rotor with a uniform shaft segment is modeled for undamped torsional motion analysis, while satisfying all the boundary conditions. This eventually generates governing equations for the torsional critical speeds of the system. The set of governing equations has the form of a sparse and banded matrix. The elements of banded matrix can be arranged in partitions, which correspond to the specific boundary of the rotor. This permits an automatic generation of the system matrix using a computer. In order to calculate the determinant generated by the simultaneous equations, which leads to the torsional critical speed, a recurring numerical algorithm for a (3*4) sub-matrix has been used. This numerical algorithm practically examines successive (3*4) sub-matrix, one at a time, instead of treating a huge matrix. The output of the program provides the mode shapes with continuous curves. The method has been implemented to three rotors given as examples : a simple rotor, Prohl's rotor, and Macmillan rotor.

펌프회전체의 임계속도해석

전오성,김정태,임병덕 한국마린엔지니어링학회 1992 한국마린엔지니어링학회지 Vol.16 No.5

A critical speed analysis of a pump shaft has been investigated. Among various methods in the shaft critical speed calculation, a transfer matrix method has been examined in this research. After a brief review on the transfer matrix method, a modeling procedure for a continuous structure has been discussed. Then, a critical speed of a multistage pump shaft has been estimated up to several low modes. Throughout an analysis, parametric effects on the bearing stiffness, a degree of the modeling order, and attachmant of the impeller have been investigated. As an application example, a critical speed analysis of a verical pump which has been implemented in domestic electric power plants for cooling water circulation has been conducted in order to provide a safe operation as far as a pump vibration is concerned.