Monitoring Offshore Pipelines Using Forced Transverse Vibration: Data Analysis

1995 ◽  
Author(s):  
Hugh E. M. Hunt
Keyword(s):  
Fluid Flow ◽  
Data Analysis ◽  
Transverse Vibration ◽  
Vibration Amplitude ◽  
Support Condition ◽  
Offshore Pipelines ◽  
Vibration Data ◽  
Wavelet Methods

Abstract Vibration methods are used to identify faults, such as spanning and loss of cover, in long off-shore pipelines. A pipeline ‘pig’, propelled by fluid flow, generates transverse vibration in the pipeline and the measured vibration amplitude reflects the nature of the support condition. Large quantities of vibration data are collected and analysed by Fourier and wavelet methods.

The Use of Vibration as a Means of Industrial Drive

1947 ◽  
Vol 157 (1) ◽  
pp. 20-31
Author(s):  
C. A. M. Thornton
Keyword(s):  
Natural Frequency ◽  
Transverse Vibration ◽  
Vibration Amplitude ◽  
Electrical Excitation ◽  
Advantages And Disadvantages ◽  
Transverse Vibrations ◽  
Industrial Drive ◽  
The Subject ◽  
And Control

The application of vibration as a means of industrial drive has been considerably developed in the last twenty years. Starting from the obvious application of screening, it has been extended to conveying, heat interchanging, consolidation of material in packages to reduce shipping space, keeping material “fluid” in hoppers and chutes, hammering, etc. The paper discusses that part of the subject involved in the production and control of the vibration by mechanical or electrical means under all conditions of load. Formulae are developed for calculation of spring strength and for the calculation of the spring dimensions, and for the avoidance of spring fatigue. The various methods of electrical excitation are compared, and the relative advantages and disadvantages are discussed. The desirable instrument equipment is described, including the remote indication of vibration amplitude. A method is outlined by which it is claimed that vibration can be maintained constant at all loads and at any desired frequency. The testing of vibrating drives at the manufacturer's works and on site is discussed. In an Appendix to the paper the problem of transverse vibrations in long vibrating conveyors is treated mathematically, and a formula is developed for the natural frequency of transverse vibration of a conveyor of any uniform section and of any length.

Development of Structural Identification Accuracy Indicators Using Fuzzy Logic

1997 ◽  
Author(s):  
Stanley E. Woodard ◽  
Richard S. Pappa
Keyword(s):  
Data Analysis ◽  
Expert System ◽  
Structural Damage ◽  
Identification Accuracy ◽  
Fuzzy Expert System ◽  
Eigensystem Realization Algorithm ◽  
Automatic Control Systems ◽  
Vibration Data ◽  
Fuzzy Membership Functions ◽  
Degree Of Confidence

Abstract A fuzzy expert system was developed for autonomous in-space identification of spacecraft modal parameters. The in-space identification can be used to validate analytical predictions, detect structural damage, or tune automatic control systems as required. A fuzzy expert system determines accuracy of vibration data analysis performed autonomously using the Eigensystem Realization Algorithm. Evaluation of the data analysis output is imprecise and somewhat subjective. The expert system was developed using the knowledge provided the co-developer of the Eigensystem Realization Algorithm. The accuracy indicator represents the analyst’s degree of confidence in the analysis results. The fuzzy membership functions of the expert system were parameterized and tuned using numerical optimization.

Measures to Reduce the Lateral Vibration of the Tail Car in a High Speed Train

1996 ◽  
Vol 210 (2) ◽  
pp. 87-93 ◽  
Author(s):  
H Fujimoto ◽  
M Miyamoto
Keyword(s):  
Vibration Amplitude ◽  
High Speed ◽  
Vibration Mode ◽  
Simulation Analysis ◽  
Lateral Vibration ◽  
High Speed Train ◽  
Aerodynamic Forces ◽  
Vibration Data ◽  
Tunnel Section ◽  
Train Vibration

From the vibration data obtained simultaneously on several cars in the same Shinkansen train, it was observed that the vibration amplitude of the tail car is greater than those of the other cars in a train. The authors' analysis arrived at the conclusion that the vibration mode of a train has a tendency for the tail car to vibrate more than the others, when the carbody hunting characteristics of a train for the yawing mode are likely to emerge, and when aerodynamic forces work in a tunnel section. Referring to those results, by simulation analysis etc., it was found that two longitudinal dampers installed parallel between the car ends (Fig. 1) with their forces depending on the angular velocity between cars, are effective in decreasing the train vibration including the tail car's vibration. Then, the prototype of the longitudinal dampers between the cars for Shinkansen was designed by obtaining the proper damping coefficient through simulation. The effectiveness of the installed damper was verified when it was tested up to 310 km/h in the Shinkansen train.

Computer Aided Analysis of Turbine Blade Vibration Test Data

1973 ◽  
Vol 6 (3) ◽  
pp. 123-128
Author(s):  
F. L. N-Nagy ◽  
S. R. Taylor
Keyword(s):  
Vibration Amplitude ◽  
Digital Form ◽  
Test Rig ◽  
Blade Vibration ◽  
Campbell Diagram ◽  
Vibration Data ◽  
Computer Aided Analysis ◽  
On Line ◽  
Analogue To Digital ◽  
Visual Record

A pilot system has been developed which automatically scans and evaluates experimental vibration data obtained from a test rig replica of a bladed wheel of a turbine in service. High vibration amplitude signals are selected for further analysis. This data is converted into digital form using an analogue to digital converter and is processed in a digital computer suitably programmed for harmonic analysis. The results are plotted on a Campbell Diagram using an on-line digital X-Y plotter which gives a visual record of the most salient information from the tests in a readily interpreted form. The paper describes the equipment used, the method of converting the analogue-type signals to digital form, analyses the accuracy of the conversion method, and gives the reasons for undertaking such vibration analysis.

A Study on Applicability of Predictive Maintenance and Vibration Data Analysis by Fast Fourier Transform into Major Equipment of Submarine

2021 ◽  
Vol 4 (1) ◽  
pp. 14-21
Author(s):  
Donghoon Kim ◽  
Sang Woo Kang ◽  
Ji Hoon Lee ◽  
Kyung Mo Nam ◽  
Seong Hun Seong ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Data Analysis ◽  
Fast Fourier Transform ◽  
Predictive Maintenance ◽  
Vibration Data ◽  
Major Equipment
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