Methods Of Technical Diagnostics Research Articles

Research of the Features of Stress-Corrosion Destruction of Gas Pipelines

The problems of stress corrosion or hydrogen blistering of gas pipelines are relevant and require careful study of the causes and factors that cause this type of corrosion-mechanical destruction of pipelines. The analysis of numerous publications on this problem revealed contradictions of information regarding the mechanism of stress corrosion and a lack of experimental materials on the substantiation of the nature and peculiarities of the nature of destruction on gas pipeline networks. Systematic experimental studies using different brands of pipe steels allowed to determine the brands of steels, which according to their characteristics are the most resistant to VBR in harsh operating conditions, including even in the most aggressive NACE environment with H2S and CO2 additives at a pressure of 10-15 atm. Moreover, the experimental studies were as close as possible to the operating conditions of pipelines of the gas transportation network. The obtained results of experimental studies can serve as a basis for developing methods of technical diagnostics and forecasting the actual state of pipelines, which will significantly prevent the occurrence of sudden destruction caused by stress corrosion. The influence of the service life of gas pipelines on the degree of flooding and microhardness of pipe steels was established, which made it possible to substantiate the embrittlement of the metal with the increase of service life. The values of impact toughness on samples with sharp and round notches and the amount of work of crack growth depending on the service life of the pipe steels were determined, which made it possible to choose steel grades characterized by the highest resistance to brittle fracture. It is shown that with the service life, the destruction occurs according to a brittle mechanism, which is confirmed by the increase in the share of the fibrous component in the fractured samples after impact tests. It was established that the lowest corrosion rate is possessed by new grades of improved steel grades 20А and 08 KhMChA.The PRFNV parameter proposed in the paper makes it possible to assess the susceptibility of pipe steels to stress corrosion cracking and provides an opportunity to regulate the corrosion crack resistance of pipelines by metallurgical methods.

WATERPROOFING OF REINFORCED CONCRETE STRUCTURES BUILDINGS AND STRUCTURES

Purpose. The purpose of the paper is to summarize the results of waterproofing, in particular, the mechanisms of the main factors of waterlogging and salinization, evaluate waterlogging and salinization and suggest ways to extend the resource, develop the technology to restore the operational characteristics of reinforced concrete structures of buildings and structures. Methodology. A review of scientific and technical sources, field studies, and regulatory documents on the technical condition of waterproofing, waterlogging, and salinization of reinforced concrete structures in buildings and structures in Ukraine was conducted to achieve this goal. The results of the analysis and synthesis of research became the basis to establish relevant waterproofing errors during design, identifying defects and shortcomings in construction and shortcomings in the long-term operation of reinforced concrete structures of buildings and structures. Findings. The analysis of domestic and foreign scientific and technical sources on the technical condition of waterproofing on old and newly built reinforced concrete structures of buildings and structures is carried out. The analysis and synthesis of problems of ensuring the reliability and durability of reinforced concrete structures of buildings and structures in their operation in air, ground and water environments is carried out. In particular, the analysis of the reasons for the failure of waterproofing systems is carried out, and the main factors – waterlogging and salinity that affect the creation of reliable waterproofing are identified. Scientific novelty. In this paper, based on the analysis and synthesis of scientific and technical sources and many studies of waterproofing of reinforced concrete structures of real objects of buildings and structures during construction and long-term operation, data on waterproofing and processes that significantly affect the degradation of structures are summarized, and conclusions are formulated regarding reliable waterproofing and protection and restoration of such structures. Practical significance. Based on the obtained generalized data on waterproofing, the conclusions present proposals to ensure reliable waterproofing of load-bearing reinforced concrete structures that are operated in moistened and saline-aggressive environments. The method of technical diagnostics and elimination of shortcomings in waterproofing and reinforcement of reinforced concrete structures, which makes it possible to increase the reliability and resources of these structures, has been developed.

DISTRIBUTION OF LAND TRANSPORT AND TRANSPORT-TECHNOLOGICAL MEANS BY OBJECTS AND TYPES OF WORK, TAKING INTO ACCOUNT THEIR TECHNICAL CONDITION

When planning the operation of land transport and transport technology facilities, their technical condition is not sufficiently taken into account. This can lead to unplanned failure of the machines and failure of the planned work by the remaining machines. The proposed methods of distributing machines by objects and types of work are based on the theory of aging of machines, but unlike the performance potential of machines, which reflects the technical condition of an average machine, they are focused on a specific machine, the probability of failure of which is determined using technical diagnostic methods. The results of the study of the dependence of the probability of failure of the car on the value of the inter-control period, the patterns of change in the probability of failure during the inter-control period and with an increase in the mileage of the car are presented. The goal is to increase the efficiency of the use of ground transportation and transportation technology facilities. Method and methodology. The theory of aging of machines, mathematical modeling, statistical methods of analysis. Results. New dependences of the probability of a car failure on the value of the inter-control period, the regularity of the change in the probability of failure during the inter-control period and with an increase in the mileage of the car are obtained and justified. The field of application of the results is the operation of ground transportation and transportation technology facilities.

ДИСТАНЦИОННОЕ ОБНАРУЖЕНИЕ УТЕЧЕК В ТЕПЛОЭНЕРГЕТИЧЕСКИХ ТРУБОПРОВОДНЫХ СИСТЕМАХ

The features of the development of technical diagnostic methods for remote control of the parameters of the operation of thermal power pipeline systems are considered, with a main focus on heat supply systems, including leak detection, as well as in the creation of software for automated control systems. Mathematical models for remote leak detection are proposed, implemented using software for regular monitoring and maintenance to ensure reliable operation of the systems under consideration. It is shown that the creation of algorithms and a system is required to detect leaks, including determining their location and scale. The created software can be used for automated control and monitoring of a thermal power system based on the results of the study. Based on the collected data related to the parameters of the heat supply system, such as pressure, gas flow and others, it is possible to build a statistical model that may include the probability distribution, expected values and variances of the parameters. The solution to the problem of specific leak detection may vary depending on the type of heat supply and the technologies used. It is shown that the study will contribute to improving the reliability and safety of heat supply systems by providing more effective detection and control of leaks and other anomalies in the operation of pipeline systems.

К вопросу использования контрольных электродов для технического диагностирования протекторов морских судов

The world statistics of fleet accidents indicate that the most dangerous type of damage to engineering structures are fragile destructions that occur suddenly and spread at high speed. The causes of brittle fractures are defects such as corrosion-fatigue cracks, which often occur due to active corrosion processes. Seawater contains a large number of microorganisms that contribute to the acceleration of corrosion and fouling of metal structures in contact with water. The main method of corrosion protection of systems and mechanisms of marine fishing vessels is tread protection. To increase the effectiveness of tread protection, it is necessary to improve the methods of technical diagnostics of treads in order to use new methods at ship repair plants and marine vessels. It is proposed to use control electrodes made of stainless steel for technical diagnostics of marine vessel protectors. Laboratory tests of a stainless steel electrode and a standard silver chloride reference electrode were performed. The experiment took place at the installation for technical diagnostics of marine protectors, which was specially developed at the Department of “Power Plants and Electrical Equipment of Ships” of the Kamchatka State Technical University. Control measurements of the potential of the working protector were performed for five days, while 50 single control measurements of the working potential of the protector were performed daily using each electrode. The accuracy of the measurement results was evaluated using a mathematical and statistical method. The results of diagnosing the potential of the tread, obtained using an electrode made of stainless steel, comply with regulatory requirements. The proposed type of electrode can be used by ship crews for technical diagnostics of marine vessel protectors.

Technologies for acoustic emission monitoring of concrete and reinforced concrete structures

Introduction. The acoustic emission (AE) method is successfully used for diagnostics and monitoring in various industries including oil and gas, nuclear, aerospace as well as in welding processes and structural corrosion. However, inspection of reinforced concrete structures seldom involves the AE method. The main reason behind is the lack of regulatory documents and specific control procedures.State Standard R 59938-2021 “Concretes. Acoustic emission testing method” was issued in 2021. Over the past few years, new data on effective application of the acoustic emission method for non-destructive testing and technical diagnostics of the building structures have been obtained. The studies were carried out on specimens and fragments of structures (reinforced concrete beams, concrete samples in the form of slabs, wall panels, etc.) in NIIZHB named after A.A. Gvozdev. The studies were conducted on the structures under construction at Kursk NPP-2.Aim. To present the results of the recently developed methods of technical diagnostics and non-destructive AE testing of concrete and reinforced concrete structures.Materials and methods. The investigations were carried out on concrete and reinforced concrete specimens made of both normal (B15–B40) and high-strength (B60–B100) concrete. A number of beams were made of fiber concrete. Structures were tested in the power unit. AE monitoring of concrete hardening involved concrete mixtures made of heavy, fine-grained, cement concrete with mineral and chemical additives. Concrete hardening was investigated remotely, with online data transmission.Results. Based on the results of the conducted study, the technologies for acoustic emission monitoring and technical diagnostics of the structures under construction and in operation have been developed.Conclusions. The given acoustic emission technologies can be used for monitoring and technical diagnostics of structures under construction and in operation. The implementation of technologies in construction will lead to the increase in safety and reliability of building structures due to the introduction of acoustic emission monitoring.

DIAGNOSTICS OF INTERNAL COMBUSTION ENGINES, STATE AND PROSPECTS IN THE ENGINEERING SERVICE
 OF THE AGRO-INDUSTRIAL COMPLEX

The paper presents the trends in the development of technical diagnostics in the engineering service of the agro-industrial complex, the most promising areas of its development. (Research purpose) The research purpose is analyzing the state of modern technical diagnostics in the engineering service of the agro-industrial complex, considering the development of new methods and technical diagnostic tools based on computer and information technologies. (Materials and methods) Modern information technologies, automated control and management systems were used during the research. The expansion of the range of devices and equipment to collect and proceed the information about the operational reliability of internal combustion engines of high-energy agricultural machinery allows for comprehensive research in the technical diagnostic. (Results and discussion) Authors used the integrated approach when conducting research in terms of developing methods of contactless diagnostics, assessing the level of maintenance using this diagnostic method, analyzing methods of contactless diagnostics that allow us to respond to the output signals of malfunctions of internal combustion engine components. Contactless diagnostics of internal combustion engines can reduce the number of failures by 1.5 or more times, increase the repair service life by 1.2-1.5 times, reduce maintenance costs by 15-20 percent, reduce fuel consumption by 12-15 percent and increase the durability of parts by 10-12 percent. (Conclusions) The research forms the scientific basis for the effective use of contactless diagnostics. The introduction of this method of technical diagnostics of internal combustion engines makes it possible to reduce the operating costs of agricultural producers by 12-15 percent due to the economical using of resources, to ensure a reduction in the number of repairs and a reduction in the number of spare parts purchased.

Creation and Non-Destructive Control of Electric Heating Elements of the Aircraft Icing Prevention System

One of the priority directions of searching for new materials and testing methods in aviation is the development of conductive composition and manufacturing of heating elements (HE) for the electrothermal anti-icing system of aircraft and their nondestructive control. Using of polymer materials with nanotubes, as well as graphenebased heaters, have low weight, fast and uniform heating, and efficient energy consumption. Conducted research using a scanning electron microscope (SEM) to optimize the composition of carbon fillers (graphene and carbon nanotubes) in composite materials for creating electrically conductive anti-icing elements of aircraft structures. One of the most important instrumental methods of technical diagnostics of potentially dangerous objects is remote infrared (IR) thermal imaging diagnostics based on the registration of the temperature field. The principle of thermal diagnostics is based on the comparison of the thermal fields of the reference and the monitored object. Temperature anomalies are indicators of defects, and the value of temperature signals and their behavior over time makes it possible to give quantitative estimates of the object's parameters. Namely, with the help of thermal imagers, non-destructive thermal control is carried out not only of propeller screws. panels of rockets and airplanes, but can also be offered to assess the quality of HE. They detect defects. cracks, structural changes, water infiltration sites and ice jams.

Information technology for creating intelligent computer programs for training in algorithmic tasks. Part 2: Research and implementation

Information technologies, particularly artificial intelligence methods, involve more and more deeply into all spheres of human activity: science, technology, art, and education. Ukraine also has sufficient potential and needs to develop educational support, which is the subject of this paper. The work aims to demonstrate the components of information technology for the creation of Intelligent Tutoring Systems (ITS), which are involved in studying various engineering disciplines. The work includes methods of system analysis, mathematical and simulation modeling, technical diagnostics, and artificial intelligence. The proposed models and methods are implemented in ITS prototypes for teaching mathematics, programming, and the automatic control theory. The Intelligent Tutoring Systems were implemented in the educational process of KhAI University and other institutions in Ukraine, Great Britain, Austria, and China. Experimental studies have shown increased student learning success rates using ITS compared to traditional methods. Improved and adapted for computer training methods of technical diagnostics, Bayesian networks, and developed models of algorithmic tasks, the learning process and the learner are valuable from a scientific point of view. In a practical sense, the obtained results can be used to create new specialized ITSs and build an expandable common learning platform integrating the basic disciplines of a specific educational field.

Improvements to the procedure for determination of the residual lifetime of railway vehicles

Existing research concerning the extention of the service life of various types of railway vehicles and assessing its remaining lifetime has been reviewed and analyzed. It has been established that the vast majority of studies relate to the assessment of the residual lifetime of various types of railway rolling stock based on the results of technical diagnostics and routine tests, as well as the assessment of corrosion wear of supporting elements and vehicles bodies. At the same time, little attention has been paid to the issue of improving existing programs and procedures of complex technical diagnostics. It was determined that the set of diagnostics operations for the extension of the service life includes routine tests of a test sample and examination of the technical condition of the metal structure of each railway vehicle for mechanical and corrosive damage.It is proposed to make changes to the existing current programs and procedures in such key sections as: terminology, objects of technical diagnostics and tests, selection of a test sample for routine tests, execution order and methods of technical diagnostics and routine tests, data processing and evaluation of results. A comprehensive approach for assessing the residual lifetime of railway vehicles is also proposed.

Environmental and operational safety of tailing storage facilities: analysis of accidents, causes and technical state diagnostic methods

A number of high-profile industrial accidents occurred at sludge and tailings storage facilities in different countries of the world are considered. The problem of ecological and technogenic danger of operating such objects, which leads to significant casualties among the civilian population, serious economic losses and harms the surrounding natural environment, is illustrated. The main causes of emergency situations have been established and analysed, it will help to reduce the risk of accidents and to minimize negative environmental consequences for similar facilities in Ukraine. The retrospective review covers the period from 1960 to 2022. During this time, about 150 cases of soil dams’ destruction in waste storage facilities were recorded. The different tendency in the frequency of accidents is noted. In particular, during the period from 1960 to 2009, there were 98 accidents with an average frequency of nearly two (1.98) per year. Over the last decade (2010-2020), the number of accidents reached 36 cases, and their frequency almost doubled to 3.6 accidents per year. Over the past two years, from the beginning of 2021 to December 2022, 10 accidents have already been registered. The vast majority of accidents during this period occurred in 34 countries of the world. The largest number of them was noted in the USA (22.4%), China (10.4%), Brazil (7.5%), Chile (6.7%), the Philippines (6.0%), Canada (5.2 %), Great Britain (4.5%) and other countries. Studies note jumps in the increase of accidents that have ten-year trends (1975, 1985, 1995, 2005). The general tendency of mass accidents since the beginning of 2015 is shown, which is substantiated by the expired terms of operation of many mining and ore enterprises (mines) and significant (exceeding normative) terms of operation of tailings storage facilities, which in some places were left without proper supervision and care. It was established that a violation of the dam slope stability (37%), an overflow of the designed capacity of the tailings storage facility (12%), seismic activity (11%), etc., are the main causes of accidents. A review of modern approaches to the management of dangerous anthropogenic objects and methods of diagnosing the technical condition of such structures was conducted. The use of a complex of organizational and technical solutions about the implementing the modern methods of assessment and control the technical condition of waste storage facilities at various levels of their operation and stages of the life cycle is proposed.

Features of creating a system of simultaneous built-in testing of deformation and temperature of composite structures by fiber-optic sensors

This article describes the relevance of improving existing and creating new effective methods of non-destructive testing and technical diagnostics of highly loaded aircraft structures made of polymer composite materials to ensure safe operation. Approaches to the creation of efficient systems for the simultaneous embedded testing of deformations and temperature of structures made of polymer composite materials by an optical method using embedded fiber-optic sensors based on fiber Bragg gratings are considered. The world experience in creating such systems, the methodology of non-destructive testing are analyzed, taking into account the creation of a spatial topology of fiber-optic sensors in a real product. It is shown that to solve this problem, it is most expedient to use the method of two optical fibers with different sensitivity to deformation and temperature, or to one of these parameters. The results of experimental studies on the simultaneous control by the proposed method of deformation and temperature of a structurally similar sample from a carbon composite processed by a vacuum method from a prepreg are presented. It has been established that the use of a quadratic model for optical control of structurally similar samples of carbon composite makes it possible to increase the accuracy of deformation and temperature measurements in comparison with the linear control model. It is confirmed that the proposed experimental technique allows for simultaneous control of deformation and temperature of structurally similar samples from carbon composites, while it can be adjusted and adapted to the actual operating conditions of a particular structure.

ПОНЯТИЯ МОНИТОРИНГА И ТЕХНИЧЕСКОЙ ДИАГНОСТИКИ ЭЛЕМЕНТОВ СУДОВОЙ ЭНЕРГЕТИЧЕСКОЙ УСТАНОВКИ

The article analyzes the maintenance and repair at the present time, thanks to monitoring systems and technical
 diagnostics. the method of carrying out maintenance and repair on the principle of operating the mechanism
 was described, according to the documentation of the shipowners' companies, which is currently in use. The
 analysis of possible updating of methods of monitoring and technical diagnostics of systems of ship power
 plants, as well as the necessary mechanisms to ensure the normal operation of the vessel is carried out. This
 method allows you to carry out maintenance and repair, as necessary, in advance before the mechanism is
 disabled, without relying on the operating time of the mechanisms. Updating monitoring systems and maintenance
 will increase the operating time of the mechanisms. In addition, when implementing this method on
 autonomous vessels in the future, it will allow for a much faster response to a possible failure of the mechanism,
 which in turn will minimize the downtime of the vessel

Study of acoustic emission signals generated by crack growth during crack resistance testing of steel specimens

The results of crack resistance tests of specimens made of 30KhGSA steel using the acoustic emission method are presented. The obtained set of characteristics can serve as the basis for the development of technical diagnostics methods of steel pressure cylinders.

Improving the Safety of Operation of Overhead Cranes with Welded Modular Construction Based on the Analysis of Their Accidents

Introduction. The article presents an analysis of the destruction of welds that occurred during the operation of modular overhead cranes. Measures are proposed to prevent the occurrence of such defects in the future, reduce the likelihood of accidents and improve the safety of operation of overhead cranes with a welded modular construction. The relevance of the work is due to the fact that in the Russian Federation approximately 65% of the lifting cranes registered with Rostechnadzor have fulfilled the standard service life.The work objective is to improve the safety of operation of modular overhead cranes and the reliability of their welded metal structures. Achieving the objectives of the work, based on the analysis of the destruction of metal structures of overhead cranes, a diagnostic map of welded joints of metal structures of end beams with modules of travelling wheels of overhead cranes was compiled. The use of the proposed diagnostic card in a production environment will significantly improve the quality of diagnostics of welded joints.Materials and Methods. Investigations of accidents of load-bearing metal structures of cranes by methods of technical diagnostics of destruction of welds that occurred during the operation of overhead cranes of modular design have been carried out. This made it possible to develop a number of measures to prevent accidents of overhead cranes initiated by the destruction of their welded modular structures.Results. Based on the analysis of accidents, a diagnostic map of destructing welded joints of metal structures of end beams with modules of travelling wheels of an overhead crane has been compiled. The use of the proposed diagnostic card will increase the reliability of welded metal structures and improve the quality of diagnostics of welded joints in production conditions.Discussion and Conclusions. As a result of the analysis of structural failures of modular overhead cranes, a number of measures are proposed to prevent the formation of such defects, the occurrence of accidents due to them, and to improve the safety of operation of overhead cranes.

On the implementation of a new method for diagnostics of pipelines

The paper reviews the necessity of using modern methods of diagnostics based on the up-to-date technologies for revealing probable damages in the pipelines and some equipment. Considering external and internal impact in the pipelines, it is necessary to conduct regular diagnostical tests. The main reason for the damages of pipelines and equipment is the formation of tension concentration as a result of the effect of some loads on these devices. Due to this, the reliability of gas pipelines in the operation is defined by a criteria of strain-stress state occured on these lines. The methods of technical diagnostics based on the up-to-date technologies should be implemented for revealing probable damages within the pipelines and equipment as well. Smart-of-the-art software technologies for performing calculations have been used in the research surveys. Within the report period, the pipeline has been tested with the method of magnetic memory (MMM) and currently is used as the most effective option.

Results of evaluating the smoothness of automatic transmission gear shifting during car operation

Various malfunctions may occur during the car operation. These include automatic gearbox malfunctions which reveal themselves during operation in the form of a rigid (jerky, bumpy) untimely engaging the up or down gear in an automatic gearbox. The quality criteria for automatic gearbox shifting which currently exist do not allow to give a reliable assessment of the required gear selection. In such cases, people operating the car often ask questions about the technical condition of the automatic gearbox and the quality of gear shift. The authors have studied the process of gear shifting, smoothness of it and peculiarities of automatic gearbox functioning of during car operation. The article describes the urgency of the problem of jerks and vibrations when changing gears. When assessing the smoothness of gear shifting, the method of technical state vibroacoustic diagnostics is applied. The method is based on the recorded parameters of vibration velocity, vibration acceleration, vibration movement with their further conversion (fast Fourier transform) into a spectral signal. The procedure of longitudinal vibration acceleration measurements on cars in operation is described. Comparative analysis of automatic gear change smoothness. As a result of the analysis the quantitative characteristics of different smoothness gear changes are obtained and its comparison with the permissible level is given. According to the results of the parameters registration and their comparative analysis, it was suggested that it is possible to assess the quality of the gear shift and determine the quantitative indicators of smoothness. Keywords: iron ore raw materials, quarry transport, process

СХЕМОТЕХНИЧЕСКОЕ И ЭЛЕКТРОДИНАМИЧЕСКОЕ МОДЕЛИРОВАНИЕ КОЛЕБАТЕЛЬНОГО ПРОЦЕССА ПЕРЕРАСПРЕДЕЛЕНИЯ ЭНЕРГИИ В БИПОЛЯРНОМ ТРАНЗИСТОРЕ

The advantage of the promising method of passive radiosensor technical diagnostics(PRTD) over the currently existing methods for determining the technical condition (vibrometry,thermal control, JTAG-testing, optical control) are: no inertia, no processor time, no galvaniccontact with the object of study. In modern scientific literature, almost no attention is paid to numericalmodels of electronic devices, including those based on bipolar transistors (BPT), whichdescribe the process of oscillatory redistribution of energy and radiation used in PRTD. Therefore,the purpose of this study is to develop the PRTD method through the development, analysisand comparison of circuit and electrodynamic models of oscillatory energy redistribution in theBPT. The paper presents and analyzes simplified circuit and electrodynamic models of oscillatoryredistribution of energy in the BPT. The parameters of the models are calculated signal radioprofiles (SRP) are obtained for the electrical component of electromagnetic radiation created bythe radio-electronic unit itself, built on the BPT. Methods for adjusting the reference parametersdepending on the actual conditions for switching on the BPT are shown. It has been establishedthat the cross-correlation function of the SRP obtained as a result of circuit and electrodynamicmodeling is not lower than 0.93, which indicates a high similarity of the presented models. Inpractice, the use of the developed models in the analysis of SRP obtained by recording the intrinsicemissions of radio engineering components of electronic devices will allow us to determine theoperating mode of the BPT and its speed with a sufficiently high accuracy. This analysis can beused in the PRTD, indicating a malfunction of the signal circuits, or degradation of the parametersof the element itself in the early stages

Method of optimal technical diagnostics and repair low-power switching power supplies

Method of optimal technical diagnostics and repair low-power switching power supplies

Unification of technical diagnostic methods of pipeline systems with the purpose of ensuring safe operation

Unification of technical diagnostic methods of pipeline systems with the purpose of ensuring safe operation