Since the beginning of the second half of the last century pioneer researches on vibration-acoustic (acoustic in that time) diagnostics (VAD) of machinery in Russia have appeared. That applied scientific area has come a long and difficult way in development: gathering the experience, changing the conceptions, specifying the models, actively developing methods and means of analysis. The correlation between the role of the monitoring of vibration state and role of "Vibration condition monitoring", i.e. vibration-acoustic analysis has changed.
The rapid development of VAD in eighties of the last century was followed by a well-known period of decline in research & development. The result of that was deficit of the subject literature. Today, due to initiative and cooperation of Russian nondestructive testing (NDT) society, including more than 200 of Russian organizations, many manuals, monographs, and tutorials devoted to methods and means of NDT, technical diagnostics and monitoring were published. However, the scientific society impatiently waits for every new book, especially, on the VAD topics.
This tutorial presents VAD as component part of machinery condition monitoring and shows both general picture and methods of practical usage of the vibration monitoring and diagnostics methodology for detection of defects and malfunctions of machinery.
This tutorial briefly touches upon general issues of VAD methodology which are discussed in a sufficient number of monographs and reference books. To be the most valuable are considered the chapters about practical usage of vibration-acoustic signals for diagnosing and selecting diagnostic features of malfunctions with specification enough for using the provided information for detection of defects and malfunctions. The illustrations, on one hand, are showing the real episodes of condition monitoring and diagnostics of machinery, and, on the other hand, are generalized in the form of spectral masks which allows their practical appliance.
The tutorial is based not only on theoretical data, but, also, on great amount of author’s experience in research, implementation and operation of diagnostic and monitoring systems. It gives full and complete picture of theoretical and practical issues of VAD and monitoring of rotor and piston machines. The content of the tutorial corresponds to the global level of development of VAD and condition monitoring of machinery, and includes the chapters which not only provide knowledge on VAD and monitoring, but, also are useful methodological matter for calculation and analytical tasks, course papers and research projects.
The tutorial is the first comprehensive educational edition in Russian Federation in the field of vibration-acoustic analysis and monitoring of machinery, recommended for publishing by the Education and Methodics Association of higher education institutions of the Russian Federation for training in the field of construction and optics engineering for higher educational students of "Instrument-making" and made for students of the 200100 "Instrument-making" of Higher Professional Training 200102 specialty "Instruments and means of diagnostic and quality control", studying such disciplines as "Automated systems for quality control and diagnostics", "Methods of technical diagnostics", "Vibration monitoring" to become specialists, masters, bachelors, or training to become a vibration-analysis NDT method expert.
Sokolova Asya Grigoryevna,
Cand.Tech.Sci., senior research associate,
head of vibration-acoustic diagnostics laboratory of the
Research Institute for Machine Science named after A.A.Blagonravov of the Russian Academy of Sciences
Balitskii Felix Yanovich,
Cand.Tech.Sci., leading researcher of R&T Center "Kachestvo".
Kostyukov V.N., Naumenko A.P. Fundamentals of machinery vibroacoustic analysis and monitoring: tutorial // Ministry of Education and Science of Russian Federation, Omsk State Technical University; DYNAMICS SPC. — 2nd edit., with amendments. — Novosibirsk: SB RAS publishing, 2014, 378 p., print run 1000, ISBN 978-5-7692-1383-0
The report addresses the real-time condition monitoring of technical state and automatic vibration analysis of auxiliary equipment’s bearing supports, in particular, the control of the feed-pump operating modes of thermal power stations. The causes that lead to premature birth and development of defects in rolling bearings are identified and the development of activities ensuring safe and continuous operation of the auxiliary equipment of thermal power stations is carried out.
Collection and analysis of vibration parameters of pumping units during their operation are realized by means of real-time condition monitoring. Spectral analysis of vibration parameters of one of the pumps showed the presence of frequency components, which mark violations in the operating practices of the pump, the development of imbalance and, as a consequence, the development of defects in the bearings after a long-term operation of the unit.
Timely warning of the personnel on the operation of the unit with "UNACCEPTABLE" state and automatic warning about the required changes the operational process allows to recover the pump operational process in due time and prevent further development of defects.
Kostyukov V.N. 2002. Monitoring of Safety of Manufacture (Moscow: Mashinostroenie).
Kostyukov V.N., Bojchenko S.N. and Kostyukov A.V. 1999. Automated Control Systems of Safe Resource-Saving Operation of Oil Refining and Petrochemistry Equipment (ACS SMSRTM™ COMPACS®) (Moscow: Mashinostroenie).
GOST R 53565 2010. Condition Control and Equipment Diagnostics. Condition Monitoring of Hazardous Manufacture Equipment. Vibration of Centrifugal Pumping and Compressor Units ( Moscow: STANDARTINFORM).
Kostyukov V.N., Tarasov E.V. Condition Monitoring and Diagnostics of Rolling Bearings of High-voltage Electric Motors during Their Operation. The 24th Int. Cong. on Condition Monitoring and Diagnostics Engineering Management (Stavanger, Norway, 30 May - 1 June 2011) pp 900-904.
Kostyukov V.N., Tarasov E.V. Real-time condition monitoring of thermal power plants feed-pumps by rolling bearings supports vibration // The 25th International Congress on Condition Monitoring and Diagnostic Engineering Management (COMADEM-2012)
The regularity and safety of the suburban passenger transportations on the Russian Federation railway lines depends on reliable functioning of each unit as well as it is substantially up to operational efficiency of more than 7,5 thousand electric train sections. Today the reliability of an electric train can be maintained by the ongoing preventive maintenance system formed on the schedule-based preventive principle which provides the list and the volume of the required control and recovery operations.
The cycle of large-volume current repair works in depot includes: uninstalling and diassembling operations for revision, repair, assembly, testing, transit of equipment and components, as well as its installation back to the electric train, which are time- and labour-consuming works. On the last stages of the cycle the repaired, checked and operative equipment may be damaged. Also, there is no guarantee for operation of the equipment within the system of the electric train because of the functionality violations.
Lack of the appropriate means and methods for the objective control of repair quality, assembling and adjustment of demanding and the most complex electric train systems especially electrical circuits, make impossible to control the quality of the carried out works. As a result, number of running electric trains with hidden problems occuring after the repair reaches 30-40%. Additionally, they can have lost of new defects caused by the“human factor”. The length of debugging stage, successful acceptance tests as well as further no-failure operation of an electric train, in this case, directly depends on qualification and other subjective qualities of the debuggers.
On the basis of the complex systems of automatic diagnostics, it is possible to change that situation as follows: to carry out the debugging stage at the repair and maintenance department reducing its duration, to provide an objective assessment of repair quality as well as assembly and adjustment of the electric train systems and equipment, and, consequently, to increase the percent of faultless results of the first acceptance test. Such systems are based on the automatic expert failure-detecting system which excludes the subjective failures of the diagnostician and provides reliable quantitative and qualitative state assessment for the most complex and demanding electric trains' systems in accordance with the requirements of the major regulative documents.
Kostyukov V.N., Kostyukov A.V., Kazarin D.V., Basakin V.V. Diagnostics of electric multiple-unit train electrical circuits’ equipment during the debugging and acceptance testing // NDT days 2012, pp. 309-313
The standard applies to the stationary piston compressors for Т2-Т6 explosive gas groups according to the classification  as well as for the stationary piston compressors using the harmful gases, 1–2 class of hazard according to GOST 12.1.007. Also, the standard sets guidance on the assessment of their vibration state during operation and acceptance tests after mounting and repair.
The standard does not apply to refrigerating and oxygen compressors, to the compressors that used to handle the radioactive gases and gases of an acetylene series as well as to the gas-engine compressors.
In accordance with the standard recommendations, the assessment of the equipment vibration state is based on the joint measurements of the displacement, velocity and acceleration of the unit casing as well as compressor mechanism or the compressor case in the direction of the vibration vector maximum.
The vibration measurements in the range from 2 to 3000 Hz are used for an assessment of the vibration state. For the in-depth study to find out the fault condition or the diagnostics, the carrying out of the vibration measurement in the range up to 10000 Hz and higher is recommended.
The standard's requirements may be used in conjunction with recommendation for assessments of vibration state of the general-purpose stationary piston compressors (see, for example, , ), including the assessment of the monitored vibration parameter value changes criteria.
The standard was developed by the Scientific and DYNAMICS Scientific & Production Center (DYNAMICS SPC), Non-Profit Organization "Research Centre on the monitoring and diagnostics of the technical system" (NPO "RDC CD").
TR CU 012/2011. On safety of equipment intended for use in explosive atmospheres.
ISO 10816-8:2014. Mechanical vibration — Evaluation of machine vibration by measurements on non-rotating parts — Part 8: Reciprocating compressor systems.
API Standard 670 (R2010) Machinery Protection Systems.
GOST ISO 10816-1-97 Vibration. Control of the machines condition by vibration measurements on the non-rotating units. Part 1. General requirements.
GOST R 56233-2014. Condition monitoring and diagnostics of machines. Hazardous equipment monitoring. Vibration generated by land-based reciprocating compressors // Introduced on 01.12.2015. Moscow: "Standardinform" - 2015 - 20 p.
Traction electric motor (TEM) is the most important assembly of the electrical-driven rolling stock (EDRS). Out of a total number of EDRS failures only about 30% are TEM failures. If one of TEM fails, it causes higher loads for other motors and that shortens the motors' lifetime.
Today there are several problems in the TEM diagnostics:
lack of the modern diagnostic systems in the depot and maintenance depot;
lack of the system viewpoint: every system diagnoses certain parameters of TEM which are not in the common base of the specific TEM.
In the article the complex diagnostic method for traction electric motor is presented. The method will allow changing of the traction electric motor repair type from the operation-based repair into condition-based repair.
Melk V.V. Developing of a method for complex diagnostics of traction electric motors // Operational reliability of locomotive park and increase of efficiency of train haulage. - Omsk: OSTU, 2012. - pp. 417-421
The paper is devoted to the new method of vibration analysis by means of the system for Real-Time Condition Monitoring of machinery (RTCM). The speed of generation and delivery of diagnostic instructions to the personnel by the RTCM systems must exceed the rate of industrial equipment degradation.
The paper presents the research on the regularity in formation of mixture of noise and periodic components of vibrations (MNPCV) of a pump. A generalized static diagnostic model of vibration has been developed to provide diagnostics of the unit by the method of recurrent selection of components from MNPCV in time and frequency domain.
The research shows that MNPCV are generated by a random process of occurrence and development of malfunctions and defects in the pump. With regard to vibration analysis, the principle of information completeness (π-principle) has been formulated. It states that in order to improve the credibility it is necessary to combine selection and use of MNPCV blocks for vibration analysis, which together form complete statistical group.
The paper illustrates the efficiency of the proposed methods in the diagnostics of defects of tooth gear, bearing, especially in the heavily loaded antifriction bearing with the radial clearance.
Kostyukov V.N. Real-time condition monitoring of gear pumps by the recurrent selection of the noise and periodic components of vibration // The Ninth International Conference on Condition Monitoring and Machinery Failure Prevention Technologies (CM-2012/MFPT-2012)
The standard applies to rotodynamic and screw pump and compressor units, driven by electric motors and/or steam turbines with gearboxes or multipliers, as well as to fans, exhausters, blowers and air cooling units with a capacity of more than 2 kW and a nominal rotation frequency from 120 to 15000 min-1 and sets guidance on assessment of their vibration state during operation and acceptance tests after mounting and repair.
This Standard is intended for usage in conjunction with GOST ISO 10816-3. This standard complements GOST ISO 10816-3 with regard to joint use of acceleration, velocity, displacement parameters as well as rates of their changes for assessment of the hazardous equipment vibration state.
The standard was developed by DYNAMICS SPC, Russian Technical Expertise, SIU "RISCOM", NPO "RDC CD".
GOST 32106-2013. Condition monitoring and diagnostics of machines. Hazardous equipment monitoring. Vibration generated by rotodynamic pump and compressor units // Introduced on 01.11.2014. Moscow: "Standardinform" - 2014 - 8 p.
The main task of the technical diagnostics is determination of an object state when the data is limited. Analysis of a state is usually done in operation when the data is hard to obtain. Often there is no way to make an unambiguous conclusion, so it may be necessary to use statistical methods.
State determination depends on the completeness of the information, and the more information about the object we have, the lower the risk of an error there is. In this way, searching the object information is a relevant question.
In addition to the statistical methods, a spectral analysis method is widespread in vibration analysis. It allows to give characteristics to a frequency content of a measured signal. Cepstral analysis and wavelet analysis are less common. Using of methods of the fractal analysis is recommended to improve reliability and accuracy of the state determination.
Kostyukov V.N., Boychenko S.N., Pavlenkov D.V. Assessment of possibility of using the fractal analysis for machinery diagnostics // Operational reliability of locomotive park and increase of efficiency of train haulage. - Omsk: OSTU, 2012. - pp. 143-149
One of the most important tasks in the increase of the maintenance quality is an improvement of the operating reliability for motor driven rolling stock (MDRS) when there are low maintenance expenses as well as a limited period of time for repair and maintenance.
In the current state the rolling stock is maintained by the schedule-based preventive repair. That’s the reason of the high consumption of resources, regardless of the real operating conditions of the unit in the MDRS. At the same time, the origin and development of defects lead to unscheduled repairs as well as additional expenditures.
The solution can be provided by the on-board condition monitoring system. It makes an assessment of the state of every unit and gives objective information about the expediency of a further operation in real time. The effectiveness of the system is in its continuous operation and making a diagnosis within a period, which is less than the period prior to a malfunction development to a critical (emergency) condition. This makes possible the gradual transition from the resource-demanding schedule-based preventive repair system to the condition-based maintenance.
Machinery of auxiliary circuits including the system of the auxiliary machines is the most important machines, which provide normal functioning of all electric train systems.
The necessity of this machinery real-time condition monitoring is caused by hard service conditions, in comparison with all-industrial machines. The following conditions could cause an early mechanical failure as well as unplanned repair: the contact mains voltage fluctuation, sudden temperature difference, the high humidity, and also vibration.
Tsurpal A.E. Selection of the parameters for diagnostics of electric train auxiliary circuits’ equipment // Operational reliability of locomotive park and increase of efficiency of train haulage. - Omsk: OSTU, 2012. - pp. 143-149
The fundamental causes of operational problems of potentially dangerous and critical objects are: low objectivity of the technical condition assessment and low observability of hidden degradation processes of technical state of the objects, caused by the wear and inadequate actions of the technological, servicing and repair personnel.
Those problems can be solved with the results of real-time technical condition monitoring of the objects. On the basis of the existing normative and scientific-methodical documents the goals and objectives of monitoring are formulated and their solutions are pointed out in the article.
The complex real time condition monitoring system is also presented there.
Kostyukov V.N., Naumenko A.P. Designing and operation experience of real-time monitoring systems // The Ninth International Conference on Condition Monitoring and Machinery Failure Prevention Technologies (CM-2012/MFPT-2012)