Assessment Of Technical Condition Research Articles

Features of simplified calculations at surveys of construction structures existing buildings (problems of admissibility and validity)

The relevance of the discussed problem is shown. The recent researches and publications on the topic are analyzed. The tasks are developed for the specified goals achievement. For the most commonly used load-bearing structures the specific features of simplified calculations in the process of buildings and structures technical state inspection are considered. The civil structures simplified calculations are classified and systematized. The simplifications systematization and their admissibility justification are carried out, which promote the achievement of the calculations reliability and efficiency maximum level. The simplifications in the design schemes drawing up and existing loads and impacts determination, as well as the simplified calculations execution are analyzed. The area of simplified calculations admissibility is identified. The algorithm (stages) for civil structures simplified calculations is developed. Some example questions to a forensic expert are considered. The questions can be predicted and resolved based on the materials of this paper by means of the civil structures simplified calculations in the course of civil engineering forensic studies. Recommendations for further researches on the topic are provided. The study purpose is to substantiate the simplified calculations permissible range for the most commonly used load-bearing structures. The scientific novelty of the work is that for the first time the validity, admissibility and systematization problems of the load-bearing civil structures simplified calculations are considered. The study results are of practical importance for the construction engineering researches on the structures technical state assessment and forensics examinations.

Assessment of Strength and Useful Life of Hydraulic Units with Partial Replacement of Equipment

Modernization and comprehensive reconstruction of hydraulic units that have exhausted their design service life are among the most important directions in the development of hydraulic power engineering over the next 10 – 20 years. Assessment of the remaining service life of the hydraulic unit as a whole and of individual assemblies that do not have to be replaced is of importance for arriving at a management decision on the need to replace elements and create a list of individual assemblies that do not have to be replaced. The existing industry regulatory base does not define the issues related to prediction of changes in technical state and individual assessment of the remaining service life of a hydraulic unit that has exhausted a lengthy service life under the conditions of actual operation in a hydroelectric power plant. This prevents us from standardizing the process of evaluating the strength and life of equipment following modernization of a unit of equipment or partial replacement of its assemblies and elements.

Assessment of technical condition of gearbox-motor-wheels and tires according to heating wear criterion when transporting building materials

The article analyzes the dynamics of tire heating depending on the operating time and the speed of a dump truck, as well as the effect of high temperature values during transportation on tire mileage. The dynamics of heating of hydraulic equipment, gearbox and hydraulic motors at different time intervals and in different working conditions is also analyzed. The task is to determine the dependence of changes in tire tread hardness on changes in tread temperature using experimental studies in laboratory conditions and to determine the direct relation to emerging loads in gearbox on the quality condition of tires. The analysis of the results of the influence of tire temperature on its properties and on early wear of hydraulic unit (gearbox) is carried out.

Assessment of the Condition of Pipelines Using Convolutional Neural Networks

Pipelines are structural elements of many systems. For example, they are used in water supply and heat supply systems, in chemical production facilities, aircraft manufacturing, and in the oil and gas industry. Accidents in piping systems result in significant economic damage. An important factor for ensuring the reliability of energy transportation systems is the assessment of real technical conditions of pipelines. Methods for assessing the state of pipeline systems by their vibro-acoustic parameters are widely used today. Traditionally, the Fourier transform is used to process vibration signals. However, as a rule, the oscillations of the pipe-liquid system are non-linear and non-stationary. This reduces the reliability of devices based on the implementation of classical methods of analysis. The authors used neural network methods for the analysis of vibro-signals, which made it possible to increase the reliability of diagnosing pipeline systems. The present work considers a method of neural network analysis of amplitude-frequency measurements in pipelines to identify the presence of a defect and further clarify its variety.

The technical condition assessment and the resource of safe operation of technological pipelines using electromagnetic-acoustic effect

The combined use of the electromagnetic-acoustic effect and a mathematical model of the dynamics of the stress-strain state of technological pipelines in the form of a transfer function to increase the reliability and accuracy of estimating their residual life, taking into account the degradation of the metal structure during operation has been justified.

Оценка фактического технического состояния нефтепровода Сирии

Оценка фактического технического состояния нефтепровода Сирии

Опыт использования экспресс-методов неразрушающего контроля для оценки технического состояния запорно-регулирующей арматуры

Опыт использования экспресс-методов неразрушающего контроля для оценки технического состояния запорно-регулирующей арматуры

Экспертная система оценки технического состояния узлов электроцентробежных насосов на основе продукционного представления знаний и нечеткой логики

Экспертная система оценки технического состояния узлов электроцентробежных насосов на основе продукционного представления знаний и нечеткой логики

ПРИМЕНЕНИЕ АППАРАТА НЕЧЕТКОЙ ЛОГИКИ ПРИ РАЗРАБОТКЕ ЭКСПЕРТНЫХ СИСТЕМ ДИАГНОСТИРОВАНИЯ ТЯГОВЫХ ЭЛЕКТРИЧЕСКИХ ДВИГАТЕЛЕЙ ПОДВИЖНОГО СОСТАВА

The paper discusses the development of an expert system for diagnosing electric traction motors of rolling stock. The diagnostic parameters of the electric traction motor commutator-and-brush assembly, being the input linguistic variables of the fuzzy model, were selected with the use of graphoanalytic model. A fuzzy mathematical model and a fuzzy neural network for comprehensive indicator of quality of mechanical machining implementing the Takagi — Sugeno fuzzy inference algorithm were developed. The authors confirmed the practicability and the adequacy of the previously proposed comprehensive indicator of quality of mechanical machining for assessing the technical condition of the electric traction motor commutator-and-brush assembly. The studies carried out allowed creating an element of intelligent expert diagnostics system that enables a comprehensive assessment of technical condition of electric traction motor.

Efficiency improvement of technical condition assessment of plunger pairs of diesel fuel equipment

Usage of an upgraded device for assessing technical condition of plunger pairs makes it possible to increase assessment accuracy and reduce the number of erroneously rejected plunger pairs. The action of this device is based on introduction of automatic hydraulic pressure test time record into the evaluation process.

Technical Accelerator and Integrated Assessment of Technical and Economic State of Fixed Assets: a Mathematical Model

The article identifies the flaws of indicators for assessing the state of fixed assets in terms of reflecting the relationship between the dynamics of technical characteristics and economic indicators of operation, the associated limitations of managerial activity in the field of investments and forecasting cash flows. It indicates the problem of the deficit and surplus of the depreciation fund. It substantiates the necessity of developing an integrated indicator of the fixed assets state expressing the relationship of their technical parameters with economic indicators of operation. Based on the essence of production, it offers an indicator of a technical accelerator and discloses its essence. The article substantiates mathematical models of the technical parameters dynamics for fixed assets and the dependence of economic indicators of operation on technical parameters. It gives an economic interpretation of the elements of regression equations. It determines the range of technical accelerator values. It develops an integral indicator of the technical and economic state of fixed assets, determines its essence and relationship with the depreciation rate, identifies the criteria of correspondence of physical wear time with depreciation time of fixed assets.

METHOD OF ESTIMATING THE TECHNICAL STATE OF THE COMBUSTION CHAMBER OF A GAS TURBINE INSTALLATION ON THE BASIS OF ARTIFICIAL INTELLIGENCE

Reliable and efficient operation of the gas-pumping unit to a large extent depends on the technical state of the combustion chamber. The poor technical state of the combustion chamber reduces not only the efficiency of the gas pumping unit, but also increases the harmful emissions to the environment of harmful substances such as nitrogen and carbon oxides. Therefore, the determination of the technical state of the combustion chamber by the results of observations on the operation of the gas turbine installation is an actual scientific task.
 As a result of the analysis of literary sources and experimental studies, it is established that the mediated parameters characterizing the technical state of the combustion chamber are the total concentration of nitrogen oxides and the mean square value of the vibration velocity of the combustion chamber body. Over time, the elements of the combustion chamber are degrading, which leads to a change in the signs of the technical state of the combustion chamber. Indicators of a technical state form a plane of signs, which, with the help of the neural network Kohonen, are divided into three areas, each of which corresponds to a certain technical state of the combustion chamber - "good", "acceptable", "permissible". A method for constructing separate curves based on genetic algorithms is developed to distinguish the areas of technical states. The equation of separate curves is taken as a polynomial of a certain degree. The developed method on the basis of the class separation criterion determines not only the parameters of the equation of a separate curve but also the structure of such an equation by minimizing the class separation criterion. With the help of the developed software of the task of the technical condition assessment of the combustion chamber, the plane of the signs is divided into three classes and separate split curves are constructed.

Theoretical basis of quality assessment of railway technical condition

The qualitative performance of the track facility in Ukraine depends upon the technical state of rail track structure, which is determined by correspondence of the characteristics to the current Regulations for laying and maintenance the track on railways of Ukraine. And the parameters indicating the rail track stability directly depend on the carrying capacity of the rail base and the stress-strain behavior.The rail base consists of elements of various physical and mechanical properties, with its own deformation behavior and stressed state under force loading. Therefore, the stress-strain behavior of the rail base must be evaluated with an appropriate mathematic model showing a flow of forces from one element to another.The rail track structure operates under the power loading from a train. This load considerably influences operation of the rail track structure and conditions the changes in the technical state in operation. In operation the technical state of the rail track structure is getting worse because the residual deformations accumulated in it, which lead to lower train traffic safety. Nowadays requirements for operational safety of the rail track structure are high, and the problem of evaluation of the stress-strain behavior of the rail base is of great importance.

A Classification Method for Select Defects in Power Transformers Based on the Acoustic Signals.

Effective, accurate and adequately early detection of any potential defects in power transformers is still a challenging issue. As the acoustic method is known as one of the noninvasive and nondestructive testing methods, this paper proposes a new approach of the classification method for defect identification in power transformers based on the acoustic measurements. Typical application of acoustic emission (AE) method is the detection of partial discharges (PD); however, during PD measurements other defects may also be identified in the transformer. In this research, a database of various signal sources recorded during acoustic PD measurements in real-life power transformers over several years was gathered. Furthermore, all of the signals are divided into two groups (PD/other) and in the second step into eight classes of various defects. Based on these, selected classification models including machine learning algorithms were applied to training and validation. Energy patterns based on the discrete wavelet transform (DWT) were used as model inputs. As a result, the presented method allows one to identify with high accuracy, not only the selected kind of PD (1st step), but other kinds of faults or anomalies within the transformer being tested (2nd step). The proposed two-step classification method may be applied as a supplementary part of a technical condition assessment system or decision support system for management of power transformers.

Наводораживающие факторы при оценке технического состояния и надежности магистральных трубопроводов

Наводораживающие факторы при оценке технического состояния и надежности магистральных трубопроводов

Diagnosis of mining and oilfield equipment by excited oscillations analysis technique

The paper presents relevance of application of non-destructive testing methods in the assessment of technical condition of the mining and oilfield machine components is justified. The prospects of diagnostics of process equipment by the excited oscillations analysis technique are proved. Design and operation algorithm of the multichannel synchronous analyzer Kamerton by LLC NPP ROS (Perm) are described. Methodological bases of defect finding using the multichannel Kamerton analyzer are described. The basic quality criteria characterizing the diagnostics-based state of technical elements are listed. It is proved that the mining and oilfield equipment technical condition assessment method by excited oscillations analysis allows carrying out operative diagnostics of technical facilities without shutdown. This method has no analogues in terms of efficiency compared to the traditional equipment nondestructive testing methods: magnetic particle, metal magnetic memory, ultrasonic flaw detection, ultrasonic thickness measurement, radiographic, metallographic, etc. In some cases, for example, for structures made of heterogeneous materials such as reinforced plastic or reinforced concrete, it is the only possible diagnosis method.

Manufacturing Errors of Concrete Cover as a Reason of Reinforcement Corrosion in a Precast Element—Case Study

The article concerns the assessment of technical condition of the precast loggia wall in a large panel building after 25 years of use as well as the cause of its damage. As a result of the study, cracks and losses of the concrete cover were found. Corrosion products were visible on exposed reinforcing rods. The reinforcement distribution and concrete cover thickness in loggia wall were estimated using a rebar detector. The corrosion assessment of reinforcement was performed using a semi non-destructive galvanostatic pulse method that allows the location of areas of corrosion and estimate the reinforcement corrosion activity. The phase composition of the concrete cover was analyzed. The test results showed an insufficient thickness of the concrete cover as the main cause of loggia wall damage. The research indicated that manufacturing errors made in the prefabrication plants affect the technical condition of precast elements and may lead to the damage of the structure well before the expected of its service life. In the case of manufacturing errors causing the implementation of an element with a concrete cover that does not meet the standard requirements for thickness and tightness, it is recommended to use protective coatings to increase the element’s durability to the designed level.

Assessment of Technical Condition of C Series Power Hydraulic Cylinders of Mounted Hydraulic Systems of Tractors

Introduction. The existing methods of assessing the technical condition of power hydraulic cylinders do not allow one to conclude about the need to restore worn surfaces of parts. The data on limit values of wear of parts (wear and tear value at which a decision is made to repair) in technical requirements to overhaul and other technical documentation of hydraulic cylinders are not currently available. The aim of the study is to determine limit values of wear of working surfaces of hydraulic cylinder parts of C series. Materials and Methods.To assess the technical condition of hydraulic cylinders used, the authors developed a device on the basis of the stand KI-28097M-GOSNITI, equipped with an independent hydraulic station and load hydraulic cylinder, at which bench tests were carried out in the operation of С series hydraulic cylinders to determine overall efficiency values. Results. Results of bench and micrometer tests of the former hydraulic cylinders of the С series (С75/30, С90/30, С100/40) are presented. The regression model of the relationship between total efficiency of C series hydraulic cylinders (С75/30, С90/30, С100/40) and wear of working surfaces of parts was obtained. According to this regression model obtained using the method of steep ascent, limit values of wear of the working surfaces of C series hydraulic cylinder parts (С75/30, С90/30, С100/40) were determined. Discussion and Conclusion.19,5 % of hydraulic cylinders of С series (С75/30, С90/30, С100/40) were operated in an out-of-limit condition. In case of technical service companies carrying out the input control of to-be-repaired hydraulic cylinders, limit values of wear for hydraulic cylinder surfaces, determined by the method of steep ascent, allow for making proper decisions on the need of their restoration.

Formation of the measuring channel for quantum diagnostic computer

Modem and perspective tasks of robotics with control from artificial intelligence systems require the use of small-sized measuring devices. In this case, the intensively developed quantum sensors and quantum computers have good prospects. Their main advantage is the ability to successfully process the data of random processes with decomposition of complex functions into simple multipliers, as well as their small size and the ability to transmit data over long distances without wires. Data transmitted over quantum communication lines cannot be copied or intercepted, which is very useful for remote control of complex technical systems. Based on the results of the probabilistic noisy data analysis quantum computer can quickly develop an assessment of the complex system technical condition. At the same time, there is no need to go through all the possible solutions to the evaluation problem with a huge amount of input data, some of which can sometimes be undefined. The main problem in the research of quantum processes is that researchers study the processes occurring in materials, but they do not indicate the ways in which quantum sensors and quantum computers are used in practical applications. This article explains how to form a measurement channel that will be compatible with a quantum computer, how to organize the input of information about the measured physical quantity into a quantum computer using a quantum sensor. The main objective was to bring the results of basic research in the field of quantum computing closer to their application in applied tasks. It is shown how the quantum processes can be shifted to the field of physical quantities technical measurements used in the automatic diagnosis of the technical state of complex systems. In the process of obtaining the results of the study, the deduction method of conclusions within the framework of a systematic approach to the development of technical systems elements was used. The result is a description of the processes in the quantum measuring channel, which is used to enter diagnostic data in a quantum computer. The study main conclusions breed the idea that quantum sensors implemented in the form of a modified diamond crystal are well described by the theory of measuring transducers with frequency output and can be used in diagnostic computers.

Algorithm of probabilistic and guaranteed assessment of the current technical condition of the aircraft’s on-board systems based on the method for testing statistical hypotheses

Algorithm of probabilistic and guaranteed assessment of the current technical condition of the aircraft’s on-board systems based on the method for testing statistical hypotheses