Assessment Of Technical Condition Research Articles

Intelligent state assessment of complex autonomous objects based on wavelet analysis

The evolutionary development of complex autonomous technical objects (CATOs), which include bodynets, unmanned vehicles, aircraft, and other robotic systems, is characterized by increased requirements for the quality of their functioning, security, and reliability under the influence of various kinds of destabilizing factors. This determines the importance of the problem of assessing their technical state, including monitoring degradation (aging) and supporting the dynamic adaptation of CATOs. To solve this problem, the article proposes a new method for intelligent assessment of the CATO technical state. The method is based on the representation of knowledge about the results of interval estimation of controlled parameters in the knowledge base of the system for assessing the CATO technical state. In this case, the process of estimating the controlled parameters is based on the application of wavelet analysis. The article discusses the architecture and implementation issues of the intelligent system for assessing the CATO technical state. A special place in this system is occupied by the knowledge base containing information about the emergency and normal states of controlled parameters. An experimental evaluation of the proposed assessment method showed that the joint use of knowledge representation processes in the knowledge base and wavelet analysis for the formation of CATO operability regions increases the accuracy and credibility of the state identification results. In addition, this approach expands the possibilities of applying technical means of control and diagnostics concerning evolving CATO.

Диагностика с помощью приборов неразрушающего контроля железобетонной облицовки и грунтового основания для оценки технического состояния дамбы Крюковского водохранилища

Purpose: to perform diagnostics using non-destructive testing devices for reinforced concrete lining and soil foundation of the Kryukovskoe reservoir dam for its technical condition assessment. Materials and methods. The materials for the study were the data of a visual survey of the Kryukovskoe reservoir, the hazardous areas, where the instrumental control by non-destructive methods was performed, were identified. Later the hazardous areas were examined in detail for the presence of defects and damage. In the course of research, an instrumental survey of the reinforced concrete lining of the Kryukovskoe reservoir was carried out in problem areas 12 km long by the Oko-3 georadar. When processing the obtained data, there is a possibility of three-dimensional visualization of the parameters of the medium under study and the attributes of the wave field. At the same time, the soil foundation of the dam was surveyed by a high-frequency detector Nokta Invenio Smart, in real time using the functions of a geoscanner, a three-dimensional model of the studied section of the soil foundation is modelled, displaying the geometric characteristics of hidden cavities and soil softening. Results. Diagnostics of the technical condition of the reinforced concrete lining and soil foundation of the dam of the Kryukovskoe reservoir was performed. The abutments of earthen structures to concrete ones, the state of temperature-settlement joints of concrete and reinforced concrete structures that could affect stability were examined. Radargrams of soil foundation subsidence locations, formed as a result of the accident and removed during the dam reconstruction, were obtained. Conclusions. On the basis of the conducted studies it was defined that the reinforced concrete lining of the reservoir dam is, in general, in a satisfactory condition and serves its functional purpose. Diagnostics of the dam foundation showed the need to strengthen the stability of the structure.

ІНТЕГРАЛЬНА ІНФОРМАЦІЙНО-ОБЧИСЛЮВАЛЬНА СИСТЕМА, ЩО ЗАБЕЗПЕЧУЄ ТЕХНІЧНЕ ОБСЛУГОВУВАННЯ ЗА СТАНОМ СИЛОВИХ ГАЗОТУРБІННИХ УСТАНОВОК

The effectiveness of the chosen maintenance strategy is determined by the completeness of information about the current technical condition of the facility. The real current state of a dynamic object should specify the list and scope of preventive and remedial work for each specific maintenance object. Existing strategies and programs according to the technical condition of dynamic objects are conditionally divided into three groups: with control over the level of reliability of the operating object; with control of the parameters of the object of operation; hybrid. Power gas turbine plants are objects of operation with high functional significance. They have an insufficient degree of redundancy, as well as a low level of operational manufacturability. Therefore, it is advisable for them to apply a maintenance strategy as per the parameter control. The article proposes general principles on the basis of which an integral information-computing system for processing parameters can be built. This system is the main element of the automated control system for the technical condition of the gas turbine power plant. Synthesized adaptive system for dynamic control of parameters characterizing the current technical state of a gas turbine power plant. Closing the control loop of the technical condition of the object with negative feedback allows you to switch from the strategy of its maintenance according to the operating time to the maintenance strategy according to the state with the control of parameters. The integrated information-computing system should solve two main tasks: a reliable assessment of the current technical state of a dynamic object and prediction of a pre-failure state in the medium and long term. The main condition for organizing the maintenance of dynamic objects according to the state with the control of parameters is the possibility of continuous monitoring of the parameters characterizing the current technical state. The choice of such parameters is ambiguous, which is due to both the specific features of dynamic object and diverse nature of relationship between faults and controlled parameters. The requirements for the determining parameters are of a general nature: the parameters must have acceptable accuracy and stability of readings over time; have the greatest diagnostic value among other parameters; not depend on changes in external operating conditions and modes of operation; based on standard measurements. The system of continuous monitoring of parameters characterizing technical state of a dynamic object must be adaptive. It should change in accordance with the change in technical condition of the gas turbine power plant. The use of a set of parameters of its dynamic linear model as characteristic of the current technical state of an object is justified for a wide class of objects. The control system of such objects operates in the stabilization mode, therefore, the adaptive system of continuous monitoring synthesized on the basis of this model provides the possibility of assessing the current technical state of the gas turbine power plant and makes it possible to predict its technical state. At the same time, the adaptation of the parameters of the linear dynamic model of the object to the new technical condition of the gas turbine plant should be carried out with the least interference in the normal operation of the plant.

A new method for assessing the physical wear of apartment buildings with defects included

The article proposes a new method for assessing the physical deterioration of residential buildings, taking into account not only the physical deterioration of structures, but also the accumulated defects in buildings. The composition of operational wear, methods for their assessment and assessment of the real technical condition of structures and buildings as a whole are analyzed. At the same time, operational wear is considered as a combination of physical and moral wear. If physical depreciation is presented as a category of technical and economic, then the assessment of the degree of this depreciation is associated with the costs spent on its elimination. The technical condition of the building structure is also affected by defects accumulated at different stages (pre-project, design stage, prefabrication stage, storage and transportation of the structure, construction and installation and operation stage) of the existence of the building. The elimination of accumulated defects also requires corresponding costs. Therefore, in the article the accumulated defects are referred to as functional deficiencies and it is accepted as functional wear and tear. And the assessment of cumulative wear in determining the real technical condition, the inclusion of this wear is necessary. This article presents an algorithm and a mathematical model for accounting for this type of (functional) wear.

Organizational and technological approaches to assessing the safety of buildings affected by emergencies

This article is devoted to the problem of assessing the safety of buildings affected by natural disasters and man-made accidents. The work describes stages of assessing the safety of buildings affected by natural disasters and man-made accidents; proposes technical and organizational measures for improving the quality of the assessment of technical condition and safety of capital construction projects; reviews main directions for solving the problem of timely organization of the process of assessing the technical condition and safety of buildings affected by natural and man-made emergencies.

Thermo-chemical degradation of industrial installations - experimental and numerical technical condition assessment

The article presents the procedure for assessing and taking into account in numerical simulations the thermal and chemical degradation of the structural material of the installation for the processing of mineral resources. Possible measurement techniques that can be used to assess the degree of wear of structural elements are described, together with an exemplary application. The assumptions for the construction of the numerical model were also described along with a detailed discussion of the obtained results. Particular attention was paid to the interpretation of the results in terms of the assessment of the technical condition.

DEVELOPMENT OF METHODS FOR EVALUATION OF TECHNICAL CONDITION OF ENGINES ACCORDING TO THE RESULTS OF INDICATION OF WORKING PROCESS ON MODES DIFFERENT FROM NOMINAL

Technical condition assessment of marine internal combustion engines by the parameters and nature of the workflow is a common practice in their operation. Taking and analysis of indicator diagrams is a mandatory procedure provided by the rules of technical operation for the main range of large and medium-sized marine engines. There is a whole arsenal of indication means for such evaluation: from classical mechanical systems to electronic means of periodic or continuous action. The rapid development of electronic control systems and changes in approaches to logistics operations in maritime transport have imposed a number of limitations, somewhat narrowing the possibilities of using these methods. Most of the vessels that form the basis of the world merchant fleet were built 10...15 years ago. Information about the results of the indication of the engines of such vessels during bench tests is presented in the form of raster images. This complicates the process of using them as the reference needed to compare them with the actual diagrams obtained in operation by means of electronic control systems, which have replaced mechanical indicators over the past few years. In addition, tendencies to reduce the speed of vessels complicate, and often make it impossible to indicate the engines in the specified operating modes. As a result, the efficiency of using indicator diagrams to assess the current technical condition is sharply reduced. In this regard, there is an objective need to compare different methods of obtaining and storing information about the results of indication and in a unified method of presenting this information, convenient for processing and analysis. In addition, there is a need to develop methods for obtaining reference diagrams for nonspecific modes on the basis of processing the results of acceptance and commissioning bench tests of a particular engine to assess its technical condition by the results of indication on the partial load modes. This study is devoted to the comparison of different methods of presenting information and obtaining reference indicator diagrams for non-specific operating modes of engines.

Data Mining Applied to Decision Support Systems for Power Transformers’ Health Diagnostics

This manuscript addresses the problem of technical state assessment of power transformers based on data preprocessing and machine learning. The initial dataset contains diagnostics results of the power transformers, which were collected from a variety of different data sources. It leads to dramatic degradation of the quality of the initial dataset, due to a substantial number of missing values. The problems of such real-life datasets are considered together with the performed efforts to find a balance between data quality and quantity. A data preprocessing method is proposed as a two-iteration data mining technology with simultaneous visualization of objects’ observability in a form of an image of the dataset represented by a data area diagram. The visualization improves the decision-making quality in the course of the data preprocessing procedure. On the dataset collected by the authors, the two-iteration data preprocessing technology increased the dataset filling degree from 75% to 94%, thus the number of gaps that had to be filled in with the synthetic values was reduced by 2.5 times. The processed dataset was used to build machine-learning models for power transformers’ technical state classification. A comparative analysis of different machine learning models was carried out. The outperforming efficiency of ensembles of decision trees was validated for the fleet of high-voltage power equipment taken under consideration. The resulting classification-quality metric, namely, F1-score, was estimated to be 83%.

1. System monitorowania zagrożeń pyłowych i akustycznych w zakładach przemysłowych wykorzystujący mierniki niskokosztowe

Among the harmful factors related to the work environment, noise and dust poses the greatest threat. Continuous monitoring of working environment parameters may be an effective solution to this problem, enabling the quick detection of areas with high noise emissions and dust concentration and their sources. Thanks to the proposed solution, OSH services will receive a tool for a quick response to exceeded exposure limit values for factors harmful to health. Such solution will also facilitate the assessment of technical conditions of installation, because excessive dust emission and/or high levels of exposure to noise may be the result of unsealing, or faulty operation of devices. The results of the meter prototype for PM2.5 concentrations of suspended dust are satisfactory. Comparative measurements of A-sound levels for different test signal levels confirmed small differences in relation to the reference meter. It was found that the prototype can be used as a tool for a quick and effective response to exceeded exposure limit values for dust and noise in an industrial plant. This article discusses the problems of occupational safety and health, which are covered by health sciences and environmental engig.

Reliability Assessment of Highway Bridges Based on Combined Empowerment–TOPSIS Method

(1) In recent years, with the continuous increase of the state’s investment in infrastructure, the construction of highways and bridges has developed rapidly, which has brought great convenience to people’s lives. At the same time, with the increase of bridge service time, the reliability of bridges declines. In order to meet the requirements of sustainable development, it is necessary to accurately evaluate the reliability of bridges. However, most of the existing evaluation methods have single-weighting and one-sidedness. There are problems such as strong subjectivity and overly simple evaluation procedures. Therefore, it is urgent to establish a new scientific bridge reliability evaluation system. (2) Methods. In this paper, a bridge superstructure is taken as the research object, and the “Technical Condition Assessment Standard for Highway Bridges” (JTG/T H21-2011) is used as the criterion to establish a bridge reliability evaluation index system. The subjective and objective weights of the evaluation indicators are based on minimum discriminant information. Each evaluation indicator is combined and weighted; then, the closeness of each evaluation object to the positive ideal solution is determined according to Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS). Finally, the reliability level of each evaluation object is determined. (3) Results. Reliability evaluation of the three-span superstructure of the bridge was carried out, and final reliability evaluation results of “Grade 2, Grade 2, Grade 2” were obtained, which are consistent with the actual working state of the bridge. (4) Conclusions. The evaluation results of this paper are consistent with the results obtained by the traditional AHP–Extenics method, but the evaluation model of this paper adopts combined weighting, which avoids the one-sidedness of the weighting of a single method—thus, the comprehensive weight obtained not only reflects the subjective intention of decision makers, but also reflects the objective properties of the data.

Complex Method of Airfield Pavement Condition Evaluation Based on APCI Index

Airfield infrastructure management should be effective. First of all, renovation works should be planned and carried out so that the equipment or resources, both financial and personal, are used optimally. The basis for planning funds should be knowledge about the actual pavement condition and, more importantly, the future pavement condition. The main goal of the paper is to present a complex method of technical condition assessment of airfield pavements made of cement and asphalt concrete, as well as natural pavements, which are part of the ground maneuvering field on each airfield. The authors propose a new method of assessing the technical condition of the pavement based on the Airfield Pavement Condition Index (APCI). Compared to existing methods, based mostly on the visual assessment of the pavement surface damages, the APCI method also includes the inventory of the repairs and diagnostic tests such as the assessment of the load capacity, evenness, anti-skid properties and the surface layer tensile bond strength. The presented mathematical models enable automation of pavement assessment process. That can lower costs and speed up whole evaluation.

Assessment of technical state of power transformers based on dissolved gas chromatographic analysis in oil

The work is devoted to the study of a power transformer based on chromatographic analysis of dissolved gases in oil. Data were obtained on dissolved gases (hydrogen, methane, ethane, methylene, acetylene) of power oil transformers of various brands with operation for more than 30 years. Particular attention is paid to the graphical presentation of the results of chromatographic analysis of the oil. As a result, the probable expected defects of power transformers were determined. Studies have shown that power transformers need immediate repair based on their assessment. Timely repair of power oil transformers allows increasing their durability and reliability of power supply to consumers.

DIGITAL TECHNOLOGIES INTO PROCESS INSPECTION OF BUILDINGS, PROPERTY AND INFRASTRUCTURE OBJECTS INTRODUCING

The paper examines the RebuildUA project, which aims to digitize, analyze and disseminate information on the destruction of buildings, property and infrastructure objects of settlements in Ukraine as a result of the Russian invasion. Providing such information to communities, public authorities and specialized funds for the reconstruction of Ukraine for further damage assessment is dictated by the urgent need for rapid territories’ reconstruction where hostilities have ended. The availability of digitized information will also simplify the process of obtaining reparations and attracting resources for reconstruction. Possibilities of modern unmanned aerial vehicles and satellite surveillance systems are shown in performing such tasks as photo and video shooting, data transmission in detecting destroyed and damaged objects, creating maps of bombing level, level of destruction, destroyed buildings and infrastructure objects, assessment of buildings damage and infrastructure objects. Photo-fixation examples of damaged objects and fragments of orthophotoplans of Kyiv region's settlements region before and after hostilities are given. It has been found that the use of modern digital technology allows to collect the necessary data on the destruction, giving experts the opportunity to obtain photos and videos of objects from different angles. This greatly facilitates and accelerates the identification of damage, assessment of the objects' technical condition and the determination of losses suffered by property owners as a result of destruction. However, the number of destroyed and damaged objects is so large, and the deadlines are so critical that the process of forming expert opinions requires automation. This will be the subject of further work.

Accuracy Evaluation of Thermoelastic Stress Analysis with the Use of Experimental and Numerical Methods.

Thermoelastic Stress Analysis (TSA) is one of the very few methods allowing the determination of a continuous stress distribution on the object’s surface under variable loading conditions. Such results provide a lot of valuable information in the field of technical condition assessment and residual life prediction. In order to improve the accuracy of the TSA, the Lock-In signal processing method is implemented. This research is aimed at verifying the effectiveness of this improvement and determining the TSA stress detection threshold, as it is important information in terms of the applicability of this method in the low-stress conditions encountered in considerations of fatigue of load-carrying structures. A steel sample with a centrally located hole was subjected to cyclic loads to determine the threshold of stress detection and accuracy of TSA. As a result of the research, the relationship between the magnitude of stress excitations and the underestimation of the measured stresses was developed. Based on the conducted investigations, it was concluded that reasonable TSA results can be acquired for excitations that induce a temperature response above 10 mK (0.5 NEDT). The presented field test example proves that in industrial applications reasonable results can be acquired for thermal responses below the NEDT of the IR camera. It was concluded that it is possible to successfully implement TSA in low-stress applications (temperature response below NEDT).

Diagnostics and technical condition assessment of large-panel residential buildings in Poland

In the 1970s and 1980s, large-panel constructions were a popular residential building technology in the Central European countries of the so-called “Eastern Bloc”. Now, these over 50-year-old structures are still in use despite changing requirements and standards of use. The paper presents typical technical problems in prefabricated buildings in Poland and possible solutions. Both in situ and laboratory tests were conducted; mechanical, physicochemical, and structural tests were carried out in more than 400 selected buildings. This analysis set the basis for developing diagnostic methods used to predict the technical condition of large-panel constructions in Poland. An official technical report was also prepared as a basis for introducing legislative work at the Sejm of the Republic of Poland, which was completed in 2020. As a result, laws were adopted with the view of providing financial support to local governments so that they can carry out technical modernisation works in large-panel buildings in Poland. The project has been ongoing for ten years and will include more than 2000 pre-fabricated buildings.

Peculiarities Research of Buildings and Structures Energy Efficiency

The constant buildings growth inevitably increases volume and work cost on their technical diagnosis. This defines the relevance of introducing non-destructive testing modern methods, which accelerate diagnosis, obtain a reliable assessment of technical condition and residual resource reasonable prognostication in safe operation field. Priority are control methods that do not require facility decommissioning, which provides a significant time and money reduction. Currently, infra-red thermal imaging using interest has significantly increased. This is due to the adoption of Russian Federation regulatory documents on improving energy efficiency and energy-saving technologies introduction in the construction and buildings reconstruction. Sweden, Canada and the United States developed a significant number of standards and guidelines for practical examinations of buildings and structures using thermal imaging quality control methods of building constructions thermal insulation at the end of the last century.On the other hand, relatively inexpensive matrix detectors of infrared radiation have been developed and put into widespread use, as a result of measurement models have become available.In the Bashkortostan Republic based on the analysis of thermal imaging studies of housing, civil and industrial construction projects, energy-efficient building construction have been developed and proposed.

Application of Multi-Criteria Analytic Methods in the Assessment of the Technical Conditions of Small Hydraulic Structures

Increasing water demand, combined with unfavourable climate change, creates a need for well-thought-out water management. Such goals are realised thanks to appropriate hydrotechnical infrastructure, the efficiency and functionality of which depend on its technical condition. In the literature, there is no method for the assessment of the technical condition of small damming structures, including sluice gates. The aim of this article was to present the possibility of using the multi-criteria AHP decision support method to assess the technical condition of small damming structures. The assessment included both concrete elements (spillways, abutments, and apron) and steel elements (gates and hoisting equipment). The analyses considered the effects of growing vegetation, the condition of concrete surfaces (e.g., cracks, cavities, exposed rebar) and steel elements (corrosion, deterioration). A hybrid method was used to study the assessment of the technical condition of water structures. It consisted of a modified Zawadzki’s method and weights which were determined by different groups of respondents with industry backgrounds (university students and experts) using the AHP method. The obtained results show that the factors related to the holes and corrosion of the gate elements had the highest value of the matrix solution vector. The last level of the tree structure indicated that the condition of the spillway and gate is the most important factor in the technical condition assessment. As the assessment considers commonly available parameters, the proposed method is universal and can be used in the assessment of other structures of this type in different regions of the world, which is important in terms of their functioning, planned repairs, and optimal use in water resource management.

КРИТИЧЕСКИЙ АНАЛИЗ ИНЖЕНЕРНОЙ ЗАЩИТЫ НИЖНЕЙ КУБАНИ В УСЛОВИЯХ ВОЗРАСТАЮЩЕГО ДЕФИЦИТА ОРОСИТЕЛЬНОЙ ВОДЫ ИЗ-ЗА КЛИМАТИЧЕСКИХ ИЗМЕНЕНИЙ

Purpose: to study the performance of hydraulic structures of engineering protection of the Lower Kuban, based on the technical condition assessment using non-destructive gauges. Materials and methods. The studies were carried out on various structures, taking into account the conditions for the formation of environment improving potential in the territory of southern Russia, using the example of Krasnodar Territory. Field studies and field tests were carried out according to the methods of Kuban State Agrarian University. The studies of the engineering protection system using a complex of non-destructive gauges which made it possible to get the most complete and accurate information about a spatial object, have been carried out, the physical-mechanical and filtration properties of soils were determined in individual reference sections by traditional methods. Results. It has been determined that on engineering protection embankments, the filtration properties of composed ground depend on the degree of their compaction, the composition of bulk soils and the formation of drying cracks. The survey with non-destructive gauges was carried out using a georadar. The steel reinforcement by the hodographs of high-amplitude refracted waves was determined. The dimensions of the cracks by the violation of the amplitude reflection tracking were determined. When carrying out electrical exploration work on an earth low-pressure levee, the method of vertical electrical sounding was used. As a result of data processing and interpretation, the geoelectric sections of specific soil resistance were obtained. Conclusions. The main reasons for the flood damage increase are socio-economic reasons, manifested in the active and at the same time irrational use of flood-prone areas. Results of the study confirm the effectiveness, productivity and information value of applicable geophysical methods at relatively low cost.

АНАЛИЗ ДЕФОРМАЦИЙ И НАПРЯЖЕНИЙ ОБОЛОЧКИ ВЕРТИКАЛЬНЫХ СТАЛЬНЫХ РЕЗЕРВУАРОВ ПО ДАННЫМ ЛАЗЕРНОГО СКАНИРОВАНИЯ

The article considers a new technology of measurements of vertical steel tanks (ground-based laser scanning), which delivers a huge volume of unstructured information. There has been carried out a review of existing methods for solving tasks of tank walls' defomations determinations on laser reflec-tion point cloud. It is noted that the accuracy of laser scanning and scans' stitching is sufficient for tank walls' defomations determinations. The existing methods are implemented basically through building irregular triangular surfaces of tank shell on which then surface profiles are built manually or semi-automatically and the defomations are determined and compared to tolerance values. The au-thors suggest a method and algorithm for processing laser reflection point cloud, which by means of several infiltrations by height, radius tolerance and inclinations and interpolation by collocation meth-od is drawn to a rectangular topologically equivalent grid. These allow by several orders to decrease the information volume stored in the database, and regular grid model structure allows to apply numer-ical calculation method for calculating strains occurring in the tank walls. The strains are determined on semi-momentless theory for cylinder shell calculation. The method and algorithm are implemented in geodetic subsystem of automatic system of technical maintenance and repairs of equipment on the oil processing plant. The suggested method will allow in the future to move from normative assess-ment of technical tank state to the assessment on actual strains, which gives objective assessment of tank state for making substantiated decision on the prolongation of its exploitation, current mainte-nance and repair.

The current state of springs – geological monuments of nature (Belgorod oblast, Volokonovskiy district)

The current state of springs which belongs to natural monuments of regional significance on the territory of the Volokonovskiy district (Belgorod oblast) was considered, special attention is paid to three objects that are included in the group of hydrological - hydrogeological monuments of nature. Extremely uneven distribution of hydrological-geological monuments of nature on the territory of the oblast was determined. During the continuation of monitoring studies, certification of the studied springs, assessment of sanitary and technical condition, recreational and cultic significance was carried out. The differences of springs in their outputs, the karst nature of some of them, and irregular use for recreational purposes have been ascertained. Springs have ceased to be «gushing». The necessity of continuing monitoring of the state of springs and further work on the development of criteria for classifying them as geological monuments of nature, as well as the coordination of the status of such springs at different levels was substantiated.