Field test investigations for condition monitoring of a concrete culvert bridge using vibration responses

2020 ◽  
Vol 27 (10) ◽  
Author(s):  
Solomon T.K. Lin ◽  
Ye Lu ◽  
Mehrisadat Makki Alamdari ◽  
Nguyen L.D. Khoa
Keyword(s):  
Condition Monitoring ◽  
Field Test ◽  
Vibration Responses

scholarly journals A Speed-Variant Balancing Method for Flexible Rotary Machines Based on Acoustic Responses

2021 ◽  
Vol 13 (13) ◽  
pp. 7237
Author(s):  
Andrew Peplow ◽  
Javad Isavand ◽  
Afshar Kasaei ◽  
Babak Afzali ◽  
Delphine Bard-Hagberg
Keyword(s):  
Condition Monitoring ◽  
Vibration Response ◽  
Constant Speed ◽  
Vibration Measurements ◽  
Critical Speeds ◽  
Rotary Machine ◽  
Rotary Machines ◽  
Vibration Responses ◽  
Experimental Laboratory ◽  
Run Up

As rotary machines have become more complicated, balancing processes have been classified as a vital step in condition monitoring to ensure that machines operate reliably, smoothly and safely. All rotating objects will deflect during rotation and all objects possess certain natural frequencies in the absence of rotation. However, an unbalanced object can cause significant unwanted deflection created by resonant vibration at a frequency (cycles/second) close to certain rotational speeds (rotations/second), known as critical speeds. This is especially important for flexible machines which normally work at rotations above their critical speeds. Imbalance is a common problem in flexible rotating machinery that can lead to extreme vibration and noise levels. This is one of the major reasons for studying various balancing methods applied to the vibration response of rotating machines. Recently, the relation between acoustic and vibration response during a rotary machine balancing process based on the original Four-Run method has been presented for constant speed machines. This method cannot be applied to machines in start-up or shut-off. Hence, by considering the acoustic and vibration responses of a machine between its critical speeds, this research presents a new innovative speed-variant balancing method based on the original Four-Run method, named as (PPCS) Peak to Peak for Critical Speeds. The proposed method consists of two major types of application: the first is in the run-up of the machine and the second is in shut down. Experimental laboratory results show that this method can be implemented for speed-variant and flexible rotary machines during run-up or shut-down transient processes based on acoustic and vibration measurements. Further, the results show the same trend in acoustic and vibration responses during balancing process which was shown for constant speed rotary machines. With a 40% improvement in response compared to around 55% obtained by traditional vibration measurements, the results found show an appreciable benefit in an alternative acoustic methodology that may have not been considered previously for run-up and shut-down issues. In addition, since only the magnitude of response is required and this is a non-contact technique an acoustic-only methodology, it can be employed with some confidence as an innovative and readily available method for condition monitoring.

scholarly journals A Speed-Variant Balancing Method for Flexible Rotary Machines Based on Acoustic Responses

2021 ◽  
Author(s):  
Andrew Peplow ◽  
Javad Isavand ◽  
Afshar Kasaei ◽  
Babak Afzali ◽  
Delphine Bard-Hagberg
Keyword(s):  
Condition Monitoring ◽  
Vibration Response ◽  
Contactless Method ◽  
Critical Speeds ◽  
Rotary Machine ◽  
Start Up ◽  
Rotary Machines ◽  
Vibration Responses ◽  
Experimental Laboratory ◽  
Run Up

As rotary machines have become more complicated, balancing processes have been classified as a vital step in condition monitoring to ensure machines operate both reliably and safely. This is especially important for flexible machines which normally work at rotations speeds above critical limits. Imbalance is a common problem in flexible rotating machinery that can lead to extreme vibration and noise levels. This is one of the major reasons for studying various balancing methods applied to the vibration response of rotating machines. Recently, the relation between acoustic and vibration response during a rotary machine balancing process based on the Four-Run method has been presented for constant speed machines. This method cannot be applied to machines in start-up or shut-off. Hence, by considering the acoustic and vibration responses of a machine between its critical speeds, this research presents a new innovative speed-variant balancing method based on the original Four-Run method, named as "Peak to Peak for Critical Speeds (PPCS)". The proposed method consists of two major types of application: the first is in the Run-up of the machine and the second is in Shut-down. Experimental laboratory results show that the PPCS method can be implemented for speed-variant and flexible rotary machines during run-up or shut-down transient processes based on acoustic and vibration measurements. As a phase-less and a contactless method, the PPCS can be employed as an innovative and readily available method for condition monitoring in the future.

Evaluation of On-Line DGA Limit Values and Calculation of Detecting Intervals for On-Line Monitoring Equipment for Transformers

2014 ◽  
Vol 986-987 ◽  
pp. 1643-1646 ◽  
Author(s):  
Yang Liu Li ◽  
Zhi Yong Chen
Keyword(s):  
Condition Monitoring ◽  
Field Test ◽  
Test Data ◽  
Monitoring Equipment ◽  
Limit Values ◽  
Equipment Monitoring ◽  
On Line ◽  
Monitoring Service

Methods presented in this paper evaluate the on-line DGA results and provide specific on-line DGA limit values. For on-line equipment monitoring transformer condition, a method to calculate specific detecting intervals according to the evaluation of on-line DGA results is proposed. An example to calculate detecting intervals is demonstrated using the field test data acquired by on-line equipment for transformer condition-monitoring service.

scholarly journals Blind Application of Developed Smart Vibration-Based Machine Learning (SVML) Model for Machine Faults Diagnosis to Different Machine Conditions

2020 ◽  
Author(s):  
Natalia F. Espinoza Sepúlveda ◽  
Jyoti K. Sinha
Keyword(s):  
Machine Learning ◽  
Fault Diagnosis ◽  
Condition Monitoring ◽  
Operating Conditions ◽  
Machine Vibration ◽  
Identical Machines ◽  
Vibration Responses ◽  
Faults Diagnosis ◽  
Diagnosis Model ◽  
Machine Speed

Abstract Purpose The development and application of intelligent models to perform vibration-based condition monitoring in industry seems to be receiving attention in recent years. A number of such research studies using the artificial intelligence, machine learning, pattern recognition, etc., are available in the literature on this topic. These studies essentially used the machine vibration responses with known machine faults to develop smart fault diagnosis models. These models are yet to be tested for all kinds of machine faults and/or different operating conditions. Therefore, the purpose is to develop a generic machine faults diagnosis model that can be applied blindly to any identical machines with high confidence level in accuracy of the predictions. Methods In this paper, a supervised smart fault diagnosis model is developed. This model is developed using the available measured vibration responses for the different rotor faults simulated on an experimental rotating rig operating at a constant speed. The developed smart vibration-based machine learning (SVML) model is then blindly tested to identify the healthy and faulty conditions of the rig when operating at different speeds. Results and conclusions Several scenarios are proposed and examined during the development of the SVML model. It is observed that scenario of the vibration measurements simultaneously from all bearings from a machine is capable to fully map the machine dynamics in the VML model. Therefore, this developed when applied blindly to the sets of data at a different machine speed, the results are observed to be encouraging. The results clearly show a possibility for a centralised vibration-based condition monitoring (CVCM) model for identical machines operating at different rotating speeds.

Field test for environmental correlates of dispersal in hedgehogs Erinaceus europaeus

2001 ◽  
Vol 70 (1) ◽  
pp. 33-46 ◽  
Author(s):  
Doncaster C. Patrick ◽  
Rondinini Carlo ◽  
Johnson Paul C. D.
Keyword(s):  
Field Test ◽  
Erinaceus Europaeus ◽  
Environmental Correlates
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