Papers by Keyword: Vibration Monitoring

Abstract: The results of vibration signals control the processing of conductive ceramics EDM machines. It has been shown that the processing of ceramics has a number of features, which was successfully controlled with the help of additional monitoring of high-frequency vibrations.

Abstract: Gearbox plays a vital role in various fields in the industries. Failure of any component in the gearbox will lead to machine downtime. Vibration monitoring is the technique used for condition based maintenance of gearbox. This paper discusses the use of machine learning techniques for automating the fault diagnosis of automobile gearbox. Our experimental study monitors the vibration signals of actual automobile gearbox with simulated fault conditions in the gear and bearing. Statistical features are extracted and classified for identifying the faults using decision tree and Naïve bayes technique. Comparison of the techniques for determining the classification accuracy is discussed.

Abstract: The main objective of this study was to obtain the correlation between the severity of damage to the stiffness of the frame in the format of its intrinsic dynamic properties, the natural frequency of the structural system at damaged and undamaged state. In this research, a laboratory test was performed on the precast post-tension frame of a similar dimension and strength specification to Jabatan Kerja Raya (JKR) school buildings. The modal frame is a reduced in scale of 1 to 5 and subjected to cyclic lateral loadings and monitored its frequency through vibration test. The vibration test was performed at each end of the cycle of a lateral pushover test. The vibration data was recorded by accelerometers due to external forced vibration to assess its natural frequency, mode shapes and damping values of the system. This research found that there is a physical tangible relationship between natural frequency changes and stiffness in the frame. The results showed that as the severity of damage increases, the natural frequency of the frame decreases significantly, indicating that softening of the system that lead to a favorable ductility for earthquakes.

Abstract: Impact drill holes into the pile construction technology is widely used in pile foundation construction job, construction vibrating pile thus to bring the impact of the increasingly prominent on the surrounding environment, the impact of this article on the construction site of a pile of drilled hole pile construction vibration effects on the surrounding environment experiment monitored by the monitoring data analysis found that the peak acceleration increases with distance attenuation occurs quickly, on the basis of analysis of pile foundation construction vibration velocity, frequency, and duration of the impact on the surrounding buildings, it is found that the frequency of vibration velocity with less impact on the housing, the duration of the construction will have an impact. Finally, analysis of the impact acceleration caused by the building structure from the perspective of seismic intensity, vibration intensity was found equivalent vi degree seismic intensity of little effect on the surrounding structures. Furthermore, the greatest impact of vibration on the residential buildings, by the way of excavating vibration attenuation ditch to control effect of vibration is proposed.

Abstract: Rollers are widely used in the construction of infrastructure; the influence of vibratory on surrounding environment caused by roller in construction is increasingly prominent. In order to solve this problem, a monitoring experiment was conducted in a compacted subgrade construction site to show how the vibratory of roller impact on surrounding environmental. Through the analysis of compacted subgrade monitoring data show that the peak fast decline rapidly with distance attenuation, the prediction formula is: a = 1657.85 * R ^ (-1.1), Based on the impact of compacted subgrade vibration velocity, frequency, and duration on the surrounding buildings is analyzed and found that the vibration velocity and frequency are less impact on the housing, but the duration of the construction will have an impact. Lastly, from Z vibration level and seismic intensity angle, the effects of vibration on personal feelings and building structures caused by vibration acceleration is analyzed. Furthermore, the way of excavating vibration attenuation ditch to control effect of vibration is proposed to the greatest impact of vibration on the residential buildings.

Abstract: Vibration is a mechanical phenomenon whereby oscillations occur about an equilibrium point. The oscillation may be periods such as the motion of a pendulum or random such as the movement of tire on a gravel road. Vibration causes waste of energy and creates unwanted sound-noise. Monitoring such process generally possess a big problem especially for a system. The present traditional single resolution techniques could not solve this problem, coupled with the Fourier transform which seems to be one of the best method in analyzing and monitoring vibration in machineries or machinery components.This paper present a new algorithm using wavelet- packet based feature in classification of vibration signals. This study explores the feasibility of the wavelet packet transform as a tool in search for features that may be used in the detection and classification of machinery vibration signals. By formulating a systematic method of determining wavelet packet based features that exploit class specific differences among interested signals, which avoid human interaction. This new algorithm provide more effective method to achieve robust classification than traditional single resolution techniques. The new algorithm in wavelet transform techniques proved to be more efficient, better analysis, and provides better results with minimum error than any existing method.

Abstract: Along with the computer software technology, the virtual instrument is gradually become the development direction of the test area. The realizing vibration test which is analyzed by adopting the virtual instrument has become the development trend of vibration test. It firstly introduces relevant simulation technology theory, the principle of fault diagnosis, the significance and the development present situation. Then according to the research for the development current situation of condition monitoring and fault diagnosis at home and abroad, it puts forward the vibration test analysis system composed the necessary sensors, signal disposal device and data acquisition card. At last it uses labwindows software produced in NI to do the development platform.

Abstract: This paper presents a method for multi-point vibration location near-surface. Unlike traditional source location technologies, it is not using travel times of seismic waves for positioning calculation, but according to the entire seismic data record, using the wave equation migration method to calculate the source location. Similar to exploration seismic, the records from a survey line within a certain period of time are data volumes with dimensions of time and ground coordinates. Based on the data, combined with surface seismic wave propagation characteristics, by using the improved seismic depth migration algorithm, the vibration energy will return to the starting position where exactly the source location is. The method can solve the problem of location calculation error by using traditional method when several vibration at the same time or continuous vibration occurs at some point.

Abstract: In order to avoid the over discharge and less discharge situations, improve the coal recovery rate and promote the working environment of workers at the fully mechanized top-coal caving face, experiments for the research of the coal and rock character recognition were carried on underground. Vibration signal at the hydraulic support tail beam and the rear scraper conveyor under different conditions were acquired at the fully mechanized top-coal caving face using the self-developed mine portable data recorder. The time-domain indexes of the vibration signal were analyzed. Results show that the variance, skewness index and kurtosis index changes most obviously under various stage of top coal caving and can be used as the time-domain characteristic indicator for the coal and rock character recognition in the fully mechanized working face.

Abstract: In order to meet the user requirements of the rotating equipment vibration monitoring upgrade project, a distributed vibration monitoring & analysis system based on virtual instrument (VI) technology was developed, which can monitor vibration for multiply equipments and provide a lot of vibration analysis graphics. The system keep use of the old monitoring instrument, from whose BUFFER port or serial port the vibration signals can be collected, thus the upgrade expense is deduced and the upgrading is calm. The using of Lab Windows/CVI software platform not only makes the displaying interface to be similar with the old instrument panel and easy to use for operators, but also greatly shorten the time of development. In this paper, the architecture and the software function implement of the system are introduced. The system has been preliminarily tested in field and the results show that it is feasible and has good practicability.