Papers by Keyword: Condition Monitoring

Abstract: Acoustic emission (AE) method of nondestructive check is based on exertion wave radiation and their registration during fast local material structure reorganization. It is used as a means of analysis of materials, constructions, productions control and diagnosis during operating time. In the article, it is applied to structural health monitoring of Wind Turbine Gearbox (WTG). Acoustic emission testing has been used for years to test metallic structures. More recently it has become the primary method of testing WTG; all are present in the failure of WTG. AE has been very successful at detecting all of these failure mechanisms and sometimes identifying them from amplitude analysis of the AE signals. However in large structures, the high acoustic attenuation in WTG precludes amplitude analysis unless the origin of the individual signals can be identified and corrections for the distances traveled applied to the signal amplitudes. The usual method of testing WTG structures has been to apply an array of sensors spaced so that a moderate amplitude AE signal occurring midway between them will just barely trigger each sensor.

Abstract: Bearing condition monitoring confronts the most machine users. Diagnostic methods used to include bearing problems represent one of the most important challenges. The scuffing phenomenon initiation of the bearing elements produces an important increase in the vibration level and can be emphasized by the analysis of the bearing friction forces which are the most sensitive indicator of the bearing failure. Commonly used technique for damage detection is the vibration signature analysis that must be carefully utilized in conjunction with the friction torque monitoring through the strain gauges measurements. In order to detect the scuffing onset, the paper presents an experimental setup for the scuffing tests performed on a 7206 ball bearing. A virtual instrument monitoring the friction force respectively the braking torque was created. An accelerometer captures the signal from the bearing outer ring then it is processed using PCI-4451 National Instruments data acquisition board and LabVIEW soft.

Abstract: The vibration analysis aims to extract features from the measurements in order to be used for fault detection and diagnosis. Vibration response measurement is an important and effective technique for the detection of the defects in rolling element bearings. The corresponding analysis methods operate in the time domain, in the frequency domain and recently in the time-frequency domain. A quantitative determination of the defect severity and its development are useful to be determined in order to estimate the remaining useful ball bearing life. Experimental data from a bearing with a defect are collected by an accelerometer then processed to identify the passing time of a ball over a defect. The paper presents a computation model corroborated to an experimental investigation to establish the defect length of a ball bearing inner race.

Abstract: For many years crack identification methods have been studied by number of researchers. The development of crack changes dynamic behavior of rotor system. It decreases the strength of object or material. Timely detection of a shaft crack by efficient condition monitoring system would avoid severe damage and expensive repairs due to failure of rotating machinery as well as assure the safety of personnel. The shaft crack is one of the most serious faults in high speed rotating machinery. It is important to detect them before they reach the critical size and cause total failure of the shaft. Hence attention to the study of rotating shaft with crack is required. This paper gives the general introduction to the vibration analysis method for crack detection with experimental set up. From software analysis it has shown that due to crack shaft gives different deformation values for different natural frequencies.

Abstract: Take advantage of cloud computing and the internet of things, combined with the fault diagnosis expert system and knowledge sharing on automobile construction vehicle condition monitoring and fault diagnosis platform, The real-time monitoring of vehicle state in person–cars, cars–cars, enterprises–cars, reliable estimation of vehicle safety problems to improve vehicle driving safety.

Abstract: Protection equipment in intelligent substation includes Merging Unit, protection equipment and Intelligent Terminal. At present, the status of the intelligent electronic device in intelligent substation protection system is still lack of effective monitoring means. According to the characteristics that substation area protection can obtain current information of all circuits in substation through GOOSE network, a protection system conditioning monitoring relay named PSCMR is designed in this paper. Based on the principle of current differential, PSCMR can accurately identify the abnormal condition or malfunction of Merging Unit or Electronic Current Transformer and realize condition monitoring of intelligent electronic device in protection system.

Abstract: Monitoring the condition of the engine through oil analysis will help operators to get the most value from their equipment and their lubricant. This is just one part of an overall Preventive Maintenance (PM) Program. Engine lubricant condition reflects the state of health of engine through its properties. Recognition and analysis of the correlation between engine lubricant system based on the lubricant properties and engine performance is crucial to provide insight into engine health. Aim of this paper is an investigation for prior failure of engine component through oil analysis. Engine is the heart of automobile vehicles. Engine performances are directly dependent upon the health of its components like piston, cylinder, cylinder head, crankshaft, cam shaft, connecting rod etc. Metals in lubricating oil can come from various sources, such as wear, contamination and additives. Wear metals result from friction or corrosion of the engine components; for example pistons, bushing, piston ring and bearings, during operation. Contamination can come from dirt, leaks or residual metal pieces. Additives used as detergents, anti-oxidants and anti-wear agents, are added in order to reduce engine wear. Wear of a specific component is heralded by an increase in the concentration of a particular metal, or the sudden appearance of a metal. Since different engine components are composed of different alloys, the increase of a particular metal can be used to identify impending failure of a specific component. An analysis of trace metals in engine oil has permitted the identification of wearing components before severe failure, without dismantling of the engine. Spectrometric Oil Analysis Program (SOAP). The determination of Al, Cd, Cr, Cu, Fe, Mg, Ni, Pb, Sn and Zn impurities using flame atomic absorption spectroscopy method. The used engine oil samples were digested with HCL

Abstract: Since the measurement of mechanical seals film thickness is difficult, the condition monitoring method based on empirical mode decomposition (EMD) is proposed. EMD is a time-frequency analysis method. It is adaptive and does not need predefined decomposition basis function. The AE signal is decomposed into a series of Intrinsic mode function (IMF) with independent characteristics of different time scales and different frequency band. It is realized that the mechanical seal contact status is accurately identified through extracting the feature of correlation coefficient which is calculated between original AE signal and multi-scale Laplace wavelet.

Abstract: An on-line monitoring system of hydrodynamic lubricant supply conditions for the back-up roll’s oil film bearing of 1420mm cold rolling mill was developed for providing real time monitoring so as to avoid unexpected breakdown of the production line. The monitoring parameters of supply pressure, supply temperature and supply flow rate show that the monitoring system software with real-time event trigger mechanism and intelligent storage algorithm solves the issue of data overflow in the continuous record and ensure the safety of data transmission. Test results for hydrodynamic lubricant supply conditions in the industrial production are reported, which indicated that established software architecture and programming methods construct a stable and reliable monitoring system, which provides early warnings for the safe production.

Abstract: Different signal processing methods are applied to experimental data obtained from a rolling element bearing rig in order to perform damage detection. Among these methods the Teager-Kaiser energy operator is also proposed as a more novel approach. This energy operator is an amplitude-frequency demodulation method used in this paper as an alternative to the Hilbert Transform in order to perform envelope analysis on the datasets analysed.