A New Method of Modeling Gear Faults

1982 ◽  
Vol 104 (2) ◽  
pp. 259-267 ◽  
Author(s):  
R. B. Randall
Keyword(s):  
Mathematical Models ◽  
Dynamic Properties ◽  
Vibration Signal ◽  
New Method ◽  
Detailed Knowledge ◽  
Signal Averaging ◽  
Monitoring And Diagnosis ◽  
Cepstrum Analysis ◽  
Alternative Approach ◽  
Types Of Faults

Detailed mathematical models of gear vibrations have appeared in recent years, but to utilize them requires a detailed knowledge of the gearbox components and their dynamic properties. This paper presents an alternative approach which is applicable to the monitoring and diagnosis of gearbox faults based on an analysis of changes in the vibration signal, showing how these can be related back to various classes of fault. Most emphasis is placed on the effects of the various types of faults on the spectrum, but the applicability of two other techniques, viz., synchronous signal averaging and cepstrum analysis, is also discussed comparatively, making use of practical examples.

Identification of ’Effective’ Linear Joints Using Coupling and Joint Identification Techniques

1998 ◽  
Vol 120 (2) ◽  
pp. 331-338 ◽  
Author(s):  
Y. Ren ◽  
C. F. Beards
Keyword(s):  
Dynamic Properties ◽  
Real Life ◽  
Model Parameters ◽  
Coupling Technique ◽  
Alternative Approach ◽  
Identification Technique ◽  
Joint Identification ◽  
Stiff Joint ◽  
Almost All ◽  
Identification Techniques

Almost all real-life structures are assembled from components connected by various types of joints. Unlike many other parts, the dynamic properties of a joint are difficult to model analytically. An alternative approach for establishing a theoretical model of a joint is to extract the model parameters from experimental data using joint identification techniques. The accuracy of the identification is significantly affected by the properties of the joints themselves. If a joint is stiff, its properties are often difficult to identify accurately. This is because the responses at both ends of the joint are linearly-dependent. To make things worse, the existence of a stiff joint can also affect the accuracy of identification of other effective joints (the term “effective joints” in this paper refers to those joints which otherwise can be identified accurately). This problem is tackled by coupling these stiff joints using a generalized coupling technique, and then the properties of the remaining joints are identified using a joint identification technique. The accuracy of the joint identification can usually be improved by using this approach. Both numerically simulated and experimental results are presented.

scholarly journals Determination of Period of RC Buildings by the Ambient Vibration Method

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Mehmet Inel ◽  
Hayri Baytan Ozmen ◽  
Bayram Tanik Cayci
Keyword(s):  
Natural Vibration ◽  
Dynamic Properties ◽  
Shear Walls ◽  
Vibration Signal ◽  
Analytical Models ◽  
Ambient Vibration ◽  
Seismic Behaviour ◽  
Infill Wall ◽  
Infill Walls ◽  
Vibration Period

Determining the dynamic properties of structures is important for understanding their seismic behaviour. Ambient vibration signal measurement is one of the approaches used to determine the period of structures. Advantages of this method include the possibility of taking real-time records and presenting nondestructive and rapid solutions. In this study, natural vibration periods are calculated by taking ambient vibration signal records from 40 buildings. The height of the building, infill wall effect, presence of seismic retrofit, and presence of damage are taken into consideration, and their effects on natural vibration periods are investigated. Moreover, the results are compared with the analytical methods to reveal the differences. A significant correlation between the period and height of the building is observed. It is seen that the natural vibration periods of the buildings decrease by 7% to 30% (15% on average) due to infill wall contribution. However, the efficiency of infill walls decreases as the building height increases. Another significant result is that adding shear walls substantially decreases the vibration period values by 23% to 33% with respect to the shear wall ratio. When the analytical estimates and measured building period results are compared, it is seen that analytical models have closer period estimates before infill walls are implemented. The limited data in scope of the study suggest that significant differences may present in the analytical and measured periods of the buildings due to infill wall contributions.

Research on Tooth Profile Deviations Measurement Method Based on the Optical Image Measuring Instrument

2013 ◽  
Vol 712-715 ◽  
pp. 1979-1982 ◽  
Author(s):  
Qing Hai Wang ◽  
Feng Xia Zhao
Keyword(s):  
Mathematical Models ◽  
Measurement Method ◽  
Tooth Profile ◽  
Optical Image ◽  
New Method ◽  
Profile Measurement ◽  
Measuring Instrument ◽  
Profile Deviation ◽  
Form Deviation ◽  
Fitting Error

To resolve the problems of small module gear measurement with traditional methods, a new method for measuring the tooth profile deviations of small module gear using the optical image measuring instrument is put forward. According to the ISO 1328-1, the mathematical models of total profile deviation, profile form deviation and profile slope deviation are proposed. The involute profile measurement schemes are given. The results show that tooth profile coordinate values of small module gear can be measured automatically and effectively with the optical image measuring instrument, and the provided method has higher precision of getting measuring points and less fitting error of tooth profile.

A new method to access information for underground omni-dimensional vibration vector

Sensor Review ◽  
2015 ◽  
Vol 35 (1) ◽  
pp. 125-132 ◽  
Author(s):  
Jian Li ◽  
Ying Liu ◽  
Yan Han ◽  
Xianhui Chen
Keyword(s):  
Vibration Signal ◽  
Vibration Sensor ◽  
New Method ◽  
Underground Explosion ◽  
Sensor Calibration ◽  
Signal Acquisition ◽  
Element Analysis ◽  
Content Type ◽  
Sensor Structure ◽  
Vector Signal

Purpose – The purpose of this paper is to propose a new method to achieve omni-directional vibration vector signal acquisition, and use this method to improve the accuracy of the underground explosion point localization. Design/methodology/approach – Following an introduction, this paper describes the design principle of a sensor structure, and discusses the rationality of the spherical structure of the sensor through finite element analysis. The sensor prototype is designed according to the above method, and its performance is tested by the sensor calibration experiment. Finally, applications are also discussed. Findings – This paper shows that the method for underground omni-directional vibration signal acquisition is reasonable and feasible. The vibration sensor, designed by this method, of which the triaxial dynamic characteristics are consistent, and the three-dimensional vibration information acquired by this sensor can achieve high-precision localization for an underground explosion point. Originality/value – The paper describes a new method for omni-directional vibration vector signal acquisition. The vibration sensor is developed based on this method, which has a broad application prospect in the positioning of an underground explosion point, the evaluation of explosive power and other underground projects.

CAD Application on Manufacture of Forming Shoulder for Packaging Machines

2008 ◽  
Vol 392-394 ◽  
pp. 161-165 ◽  
Author(s):  
Y.J. Zhou ◽  
Qiu Ju Zhang
Keyword(s):  
Theoretical Analysis ◽  
Mathematical Models ◽  
Theoretical Basis ◽  
Vertical Tube ◽  
Test Tube ◽  
New Method ◽  
Packaging Machine ◽  
Shape Curve

Based on the theoretical analysis of forming shoulder used in fill-and-seal packaging machine, this paper presented the 2-D and 3-D mathematical models of offset bending curve jointing the vertical tube and shoulder parts. According to the technology widely used in the manufacturers, the theoretical basis was provided for preparing the rough parts to make the shoulders. Furthermore, a new method using test tube was proposed to check the shape curve and locate the shoulder parts before welding. Transformed from 3-D offset bending curve, the 2-D cutting data of test tube was also provided for practical use.

Fault Diagnosis to a Rolling Bearing in a Blowing Machine Based on the Theories of EMD and Intrinsic Modal Energy Entropy

2011 ◽  
Vol 284-286 ◽  
pp. 2461-2464
Author(s):  
Hai Lan Liu ◽  
Xiao Ping Li ◽  
Yan Nian Rui
Keyword(s):  
Fault Diagnosis ◽  
Classification System ◽  
Vibration Signal ◽  
Rolling Bearing ◽  
New Method ◽  
Support Vector ◽  
Rolling Bearings ◽  
System A ◽  
Energy Entropy

Based on the research of the theory and the experiment of EMD and Intrinsic Modal Energy Entropy，the vibration signal of a rolling bearing in a Blowing Machine of a certain factory was measured when working. Then the signal was decomposed by EMD, its Intrinsic Modal Energy Entropy was calculated and used as fault feature. Finally, using a Support Vector Classification System, a satisfied effect of fault diagnosis of a rolling bearing in a Blowing Machine was got. The experiment had confirmed that the method was advanced, reliable and practical. A new method was provided for fault diagnosis of rolling bearings in some Blowing Machines.

Raman Spectroscopy Using dc Signal Detection and a Microcomputer: An Alternative Approach

1987 ◽  
Vol 41 (7) ◽  
pp. 1145-1147 ◽  
Author(s):  
E. Neil Lewis ◽  
Ira W. Levin
Keyword(s):  
Signal Detection ◽  
Laser Excitation ◽  
Excitation Power ◽  
Signal Averaging ◽  
Raman Spectroscopic ◽  
Detection Techniques ◽  
Medium Resolution ◽  
Alternative Approach ◽  
Wide Range ◽  
Generic Data

Raman spectroscopic data have been obtained with the use of direct current (dc) signal detection, an IBM PC/AT microcomputer, and commercially available software. Since photomultiplier currents of the order of nanoamps to microamps are readily attained for Raman emission under conditions of moderate laser excitation power levels (150–200 mW) and medium resolution spectral slits (1–4 cm−1), signal levels well within the domain measurable by dc signal detection techniques are achieved for a wide range of chemical and biochemical samples. Further, the digitization and signal averaging capabilities of generic data acquisition boards and microcomputers allow dc detection to yield signal-to-noise ratios competitive with those derived from complementary pulse-counting techniques.

Vibration Signal Extraction of Rotating Machines Based on the Analysis of Degree of Cylcostationary

2012 ◽  
Vol 546-547 ◽  
pp. 188-193 ◽  
Author(s):  
Yu Rong Wang ◽  
Tian Xing Wu
Keyword(s):  
Background Noise ◽  
Vibration Signal ◽  
Sampling Frequency ◽  
Hilbert Transformation ◽  
New Method ◽  
Signal Extraction ◽  
Rotating Machines ◽  
End Effect ◽  
Research Results ◽  
Rotating Machine

When early faults occur in rotating machine, the vibration signal being extraction the often contain heavy background noise .In this paper the analysis of degree of cyclostationarity (DCS) was proposed to vibration signal extraction of rotating machine. This method can overcome the shortcoming of Hilbert transformation that will be influenced by many factors, such as end effect, sampling frequency and the added noise in signal. The research results show that the DCS can not only extract vibration signal but also suppress the added noise in the signal. Therefore more accurate fault signal will be extracted and detected through this new method.

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