Use Of Non-destructive Testing Methods Research Articles

Analysis of the structural behavior of reinforced concrete components with acoustic emission analysis

The use of non-destructive testing methods can provide insights into processes within the interiors of structures. Acoustic emission testing is one of the non-destructive testing methods that allows the detection of material damage during its occurrence. When structures, such as concrete components, fail under load, elastic waves are generated, propagating within the component. These signals can be detected by acoustic emission sensors placed on the surface of the component, enabling the tracking of the material's condition and the location of failure. This paper summarizes recent applications of acoustic emission measurements on large-scale laboratory specimens made of reinforced concrete. The first example describes measurements during a tensile fatigue test on a large- scale reinforced concrete specimen to investigate the fatigue behaviour of an embedded concrete dowel. The second example involves measurements during a dynamic three-point bending test to examine the fatigue behaviour of a prestressed concrete railway sleeper. The third example describes a full-scale test conducted on a flat slab concrete test specimen with dimensions of 2.8 m × 2.8 m. The objective of these investigations is the development and optimization of new components to enhance punching shear resistance and provide an economical solution. To detect microcracking during loading acoustic emission measurement has been carried out using broadband sensors with a measurement frequency of up to 200 kHz which were especially developed for the detection of microcracks in concrete. For the three-dimensional location of the acoustic emission events, 16 of these acoustic emission sensors were attached to the surface of the specimens. Most of the events were in the centre of the sample in the punching area. These events form a circular structure with a diameter of approximately 1m. A visual inspection of the sample after the experiment shows that macroscopic cracks have formed in this area, which extend up to the surface of the sample.

Analysis of the Main Characteristics of Infrared Thermography and Ultrasonic Methods for Diagnosing Technical Object

Diagnostics of building structures is a painstaking work that requires the use of non-destructive testing methods, the main task of which is the use of research methods for diagnostic and control studies. The method of infrared thermography and the ultrasonic method of diagnostics of technical objects are of particular importance in this regard. The use of the methods of infrared thermography and ultrasonic control makes it possible to carry out observations and monitoring of historical and modern buildings in terms of the destruction of materials and structures, while the buildings themselves remain intact. For each of these methods, different measuring instruments are used, equipped with special sensors for qualitative analysis. Achievements in laboratory testing using these methods and devices allow materials to be tested based on measurable parameters. Knowledge and experience in the field of infrared thermography and ultrasonic testing are relevant for innovative research in the field of modern materials technology, building science and maintenance methods. Such research requires an interdisciplinary approach that combines the knowledge of materials science and building science.

Mathematical modeling of the influence of technological parameters of rotary molding on the amplitude of the ultrasonic bottom signal

In recent years, the processing of polymer materials has undergone significant changes due to the introduction of digital technologies. This article discusses the integration of high-tech methods and tools that ensure reliability, flexibility and optimization of production processes. In particular, emphasis is placed on the choice of non-destructive testing methods to ensure product quality, especially in the production of polymer products by rotary molding. The article discusses the problems associated with incomplete sintering and thermal oxidative decomposition of polyethylene, which have a significant impact on the quality of products. Traditional methods of control, such as visual inspection and ultrasound control, are presented, and their limitations are discussed. The main attention is paid to the application of the ultrasonic method of non-destructive testing to detect incomplete sintering of polyethylene. The authors propose a formula based on probabilistic-deterministic planning, which takes into account the combined effect of temperature and plastic thickness on the amplitude of the ultrasonic signal. This formula demonstrates high reliability, estimated by the coefficient of nonlinear multiple correlation. The use of non-destructive testing methods in the production of polymer products by rotary molding allows us to ensure high quality products and prevent possible breakdowns and accidents during operation. This article represents an important contribution to the field of quality control of polymer products and opens up new opportunities for optimizing production processes.

КОНТРОЛЬ НАЛИЧИЯ ДЕФЕКТОВ ПРИ ИЗГОТОВЛЕНИИ ИЗДЕЛИЙ МАШИНОСТРОЕНИЯ

The aim of the work is to develop an automated system of control of geometric characteristics of the part type "cylinder head" with the use of nondestructive testing methods. To achieve this goal, the paper describes the methods of diagnostics of defects of mechanical engineering products, presents the structural scheme of the modernized control and measuring system, substantiates the choice of measuring equipment, develops the methodology of measurements, performs an accuracy analysis of the measuring system, describes the procedures for verification and calibration of measuring equipment.

Influence of the Accuracy of Strength Control on the Quality of the Structures Being Erected

The influence of the accuracy of tests in the process of quality control is analyzed on the example of assessing the class of concrete in standard samples and non-destructive methods. Quality control is seen as part of the reliability triad, ensuring a level of reliability during construction. The relationship was established between the accuracy of test methods and quality control based on the result of construction. The factors influencing the efficiency increase of the quality control system are determined The prospects for the development of the accuracy of standard destructive and non-destructive testing methods are assessed. A system for evaluating and monitoring the effectiveness of testing by non-destructive methods and a connection with the reliability of the structures being erected has been developed; A rational organization of concrete strength control using direct and indirect methods is proposed. The calculation of the organizational and technical potential for the use of non-destructive testing methods has been made; assessment of the influence of changes in the structural characteristics of concrete during its long-term operation on the results of non-destructive testing of strength.

Flaw detection of ship equipment parts

The need for non-destructive testing is regulated by the rules of the Russian River Register, which can determine the choice of the method of non-destructive testing and the procedure for its implementation. Non-destructive testing methods used in naval mechanical engineering are: visual and measuring control, ultrasonic control, radiographic control, capillary control, magnetic control, eddy current control. Each of the methods, due to the difference in the implemented physical principles, has its own advantages and disadvantages, which impose restrictions on the flaw detection of parts. The analysis of the sculpted defects of ship equipment and machines, depending on the manufacturing method and operating conditions, was carried out. The limitations on the use of non-destructive testing methods are shown. Examples of non-flaw detective parts are given, the control of which is difficult, as well as flaw detective parts that can be controlled with a guaranteed condition for detecting defects. The advantage of the method of magnetic memory of metal is indicated, relative to other methods of non-destructive testing. Using the example of a piston pin of a marine diesel engine NVD 36, a comparative analysis of the applicability of ultrasonic testing methods, the magnetic memory method and the penetrating solutions method for detecting fatigue cracks was performed. The results of the control show that the applied methods confidently identify fatigue cracks in the controlled parts, machines and mechanisms of ship equipment.

TECHNICAL ASPECTS OF MEASUREMENTS USING THE PULL-OFF METHOD

The article presents an analysis of the technical use aspects of the pull-off method for testing the repair layers applied to concrete elements, based on the standards requirements. The use of non-destructive testing methods is the only option in some cases. However, it is very important to pay attention to their proper use or even preparation for research. The pull-off method requires just such diligence to be able to properly interpret the obtained results. The article compares the results of the research in which the pull-off method was used in various configurations. The obtained measurement results were compared with each other and analyzed in terms of their usefulness.

Non-destructive method for determining the mechanical properties of rolled steel

This article describes the developed methodology for the prompt and reliable determination the mechanical properties quantitative indicators of the heat-treated steel products by a non-destructive method. For these cases, the non-destructive method of testing steel products is the most optimal option, due to the fact that it does not require destruction of the controlled sample and provides for the possibility of the product further operation. The use of non-destructive testing methods also contributes to significant savings in material and time resources. The essence of the method described in this work lies in the initial study of steel samples, measuring their coercive force, maximum magnetic permeability and residual magnetic induction for subsequent statistical analysis to determine the relationship between mechanical and electromagnetic properties. As a result of finding this correlation and checking its reliability, it becomes possible to determine the ultimate strength, yield strength and relative elongation on finished products, which are normalized indicators of the steel structural products strength properties. The proposed non-destructive method for determining the mechanical properties will allow its use in the production flow, while having the reliability of determining the quality indicators above 96 %.

Relationship of Different Properties from Non-Destructive Testing of Heavy Concrete from Magnetite and Serpentinite.

Radiation-shielding concrete has been analyzed by several methods of destructive and non-destructive testing (NDT). Concretes made of crushed basalt, magnetite, serpentinite, and two different types of cement (Portland cement CEM I and slag cement CEM III/A) were studied. In this study, we analyzed concrete columns with a height of 1200 mm and a cross-section of 200 × 200 mm2. The top and bottom of the column were analyzed using data from compressive strength, dynamic modulus of elasticity, water penetration, and diffusion coefficients derived from the electrical resistivity test. This article presents the properties of fresh concrete and concrete after two years of setting. It was determined how the different ratios of basalt, magnetite, and serpentinite affect the individual measured parameters. Furthermore, correlation relations between individual resulting values were analyzed. It was observed that compressive strength generally does not correlate with other results. The diffusion coefficient correlated well with density and water penetration. Little or no correlation was observed in the diffusion coefficient with compressive strength and modulus of elasticity. The results of the study make it possible to refine the testing of heavy concretes in terms of electrical resistivity, and point to the possible use of NDT methods. The results also show which composition of heavy concrete is better in terms of effective diffusivity.

Using of artificial neural networks to assess the residual resource of trunk pipelines

A large number of oil and gas pipelines in the Russian Federation have been in operation for over 20 years. For these pipelines, the issue of assessing the residual resource is relevant. Today, much attention is paid to the problem of long-term durability of pipelines. Trunk pipelines are under the influence of cyclic loads and influences arising during operation. The acting stresses in the pipe wall do not exceed the allowable ones, however, they cause micro-damage to the metal structure. When assessing the cyclic fatigue of a metal, the main criterion is the relative damage to the metal. The use of non-destructive testing methods (ultrasonic and magnetic), as well as the establishment of a relationship between the number of cycles and diagnostic parameters, will improve the accuracy of the residual life assessment. When analyzing several diagnostic parameters, the question of data interconnection becomes relevant. Since establishing an empirical or semi-empirical relationship between ultrasonic and magnetic properties is a complex task, artificial neural networks (ANNs) can be used to solve this problem. The use of ANN in the diagnostics of trunk pipelines will increase the accuracy of the assessment and eliminate the subjectivity of data interpretation.

An An Analysis of Crystalline Admixtures in Terms of Their Influence on the Resistance of Cementitious Composites to Aggressive Environments

This paper describes the influence of crystalline admixtures on the chemical resistance of cement composites exposed to aggressive environments. The effect of the crystalline admixtures was determined by a series of physical-mechanical and innovative physical-chemical methods. Specifically, this concerned the measurement of flexural strength, compressive strength, determination of the dynamic modulus of elasticity by the ultrasonic pulse velocity test, and an analysis of the internal structure by mercury intrusion porosimetry and x-ray computed tomography. Physical-chemical analyses were also performed; namely an x-ray diffraction analysis to determine the mineralogical composition and electron microscopy to examine the microstructure. The use of non-destructive testing methods (ultrasonic pulse velocity test and computed tomography) made it possible to compare the properties of the same specimens for 16 months. The specimens were stored in reference laboratory conditions, a sodium sulphate solution and an ammonium chloride solution. The physical-mechanical tests and physical-chemical analyses clearly showed the benefit that crystalline admixtures have for the resistance of cementitious composites attacked by chemically aggressive solutions without affecting the fresh-mixture rheology or decreasing the strength of the composites.

Non-destructive testing as an element of monitoring the operational reliability of rice systems for the rational use of water resources

This article presents the results of monitoring the operational reliability of structures of an on-farm network of rice systems for the rational use of water resources. At present, the state of the water basin of the Kuban River is characterized by a high level of economic and integrated development. The amount of irretrievable withdrawal of water resources in the Lower Kuban exceeds the maximum permissible withdrawal limit by 3.5 times. Thus, the Kuban River has virtually no free water resources in the lower reaches after the Krasnodar reservoir, for further development. Studies conducted on the on-farm network facilities have shown that closed structures on rice systems are in a worse position than open ones. The drainage structure in the form of a pipe was examined in detail, since the structure is exposed and accessible for inspection and measurements. However, part of the structure that was under water during operation got serious damage; the pipeline was destroyed along the entire length from the junction to the water intake well. The use of monitoring the operational reliability of the structures of rice systems has shown the opportunity to improve the quality of the control effects of technical operation, reduce repair costs and obtain the expected economic effect, and also allows to solve the technical problems of long-term operation, classification and determination of damage volumes of the examined structures to improve the calculation of the residual reserve of capacity and establishment the duration of their continued functioning. The use of non-destructive testing methods allows you to scientifically substantiate the costs of maintenance and overhaul, to clarify the rules for operating on-farm network facilities.

Pile quality assessment by vibroacoustic method

In recent years, there has been a steady growth in industrial and civil construction, especially in large cities. Construction is often carried out in increasingly difficult geotechnical and hydrogeological conditions. This contributes to the emergence of new production technologies and diagnostic methods. The use of non-destructive testing methods allows you to quickly obtain information about various characteristics of an object without disrupting the process of its operation. This is especially true for hidden work, since access to the research object is practically closed, and its opening may entail undesirable consequences for the operation of the entire structure.

ANALYSIS OF METHODS FOR INCREASING THE WORK RESOURCE OF GROUND PUMPS

The article is devoted to the analysis of modern methods for increasing the service life of ground pumps, as well as to determine their advantages, disadvantages and opportunities for application. Groundwater pumps are one of the main types of equipment at concentrating plants, in the systems of ash and slag removal at thermal and hydroelectric power plants, in solution purification systems at drilling rigs, at cement production plants, crushing process lines, etc. They are used for pumping sand and gravel, gravel, slag, ash and slag, and other slurry. The main methods for increasing the service life of ground pumps include gas-flame and plasma spraying and surfacing of pump parts, the method of corroding and methods for monitoring the internal state of the pump. The essence of gas-flame spraying and surfacing processes consists in deposited metal powder in a flame of combustible gases mixed with oxygen on a previously prepared surface of a part or product. As a combustible gas used balloon or generator acetylene, as well as propane and hydrogen. As a result of the use of plasma spraying of powder materials, the metal plating is formed as a result of spraying of powder or wire materials that are fed to the gas-jet of the plasma torch. By the method of corroding, the worn surfaces of parts are restored to their original dimensions by applying a layer of abrasive mass. The manufacturing technique of details from abrasive mixes consists of preparation of a mix, its pressing, percolation and polymerization. Electrocorundum is used as a filling abrasive mixture. The application the methods of monitoring the internal state of the pump in order to increase the resource of its work consists in the use of non-destructive testing methods. These methods allow you to assess the overall technical condition of the equipment, if necessary, conduct an in-depth analysis of its technical condition, determine the reasons for the growth of the studied parameters, establish the defects and eliminate them, i.e. improve the reliability of equipment operation and increase its service life.

Experimental Investigations to Evaluate the Validity and Performance of NDT Procedures for In-Service Inspections

During multipass welding, cumulative and repetitive thermal phenomena may lead to development of cracks that can seriously compromise the quality of the welded joint. The use of Non-Destructive Testing methods is needed for the in-service inspection of the welded joint quality. To reliably evaluate the performance of an NDT procedure for in-service inspections, different types of artificial defects are used for this study. They have to be representative enough in comparison with the real service defects. For instance, thermal crack was realistically created by machining in a welded joint achieved by MAG welding deposition of melted SG3 wire on E36-3 steel, this case study being widely met in the crane industry. The approach consists of comparing two different ultrasonic techniques (Normal beam inspection and Angle beam inspection) in order to evaluate their performance in detecting and determining the size of well-known defects. Despite the difficulty in developing and interpreting the on-screen signals, caused by uncertainty in measuring the defect size, better results have been achieved when the angle beam inspection technique has been applied for the in-service inspections.

Looking Through Paintings by Combining Hyper-Spectral Imaging and Pulse-Compression Thermography.

The use of different spectral bands in the inspection of artworks is highly recommended to identify the maximum number of defects/anomalies (i.e., the targets), whose presence ought to be known before any possible restoration action. Although an artwork cannot be considered as a composite material in which the zero-defect theory is usually followed by scientists, it is possible to state that the preservation of a multi-layered structure fabricated by the artist’s hands is based on a methodological analysis, where the use of non-destructive testing methods is highly desirable. In this paper, the infrared thermography and hyperspectral imaging methods were applied to identify both fabricated and non-fabricated targets in a canvas painting mocking up the famous character “Venus” by Botticelli. The pulse-compression thermography technique was used to retrieve info about the inner structure of the sample and low power light-emitting diode (LED) chips, whose emission was modulated via a pseudo-noise sequence, were exploited as the heat source for minimizing the heat radiated on the sample surface. Hyper-spectral imaging was employed to detect surface and subsurface features such as pentimenti and facial contours. The results demonstrate how the application of statistical algorithms (i.e., principal component and independent component analyses) maximized the number of targets retrieved during the post-acquisition steps for both the employed techniques. Finally, the best results obtained by both techniques and post-processing methods were fused together, resulting in a clear targets map, in which both the surface, subsurface and deeper information are all shown at a glance.

Non-destructive Assessment and Health Monitoring of Railway Infrastructures

A continuous increase in the worldwide demand for high-speed traffic, freight tonnage as well as of the train operating frequency is worsening the decay conditions of many railway infrastructures. This occurrence affects economy-related business as well as contributing to rising maintenance costs. It is known that a failure of a railway track may result in tremendous economic losses, legal liabilities, service interruptions and, eventually, fatalities. Parallel to this, requirements to maintain acceptable operational standards are very demanding. In addition to the above, a main issue nowadays in railway engineering is a general lack of funds to allow safety and comfort of the operations as well as a proper maintenance regime of the infrastructures. This is mostly the result of a traditional approach that, on average, tends to invest in high-priority costs, such as safety-related costs, compromising lower-priority interventions (e.g., quality and comfort of the operations). A solution to correct this trend can be moving from a reactive to a proactive action planning approach in order to limit more effectively the likelihood of progressive rail track decay. Within this context, this paper reports a review on the use of traditional and non-destructive testing (NDT) methods for the assessment and health monitoring of railway infrastructures. State-of-the-art research on a stand-alone use of NDT methods or a combination of them for quality control, inspection and maintenance tasks in this subject area is discussed.

Systematic Assessment of Nondestructive Evaluation Techniques for Post-Tensioning and Stay Cable Systems

Nondestructive evaluation (NDE) can provide invaluable information about the condition of tendons in post-tensioned and cable-stayed bridges, which can facilitate preventative actions to mitigate further deterioration. To date, the use of nondestructive testing methods for routine maintenance of bridges has been relatively low, partly due to limitations of available technologies but mainly owing to a lack of know-how regarding existing NDE techniques and guidelines. This study aims to develop guidelines to assist bridge owners and engineers in selecting the most appropriate NDE method or combination of methods for assessing the condition of in-service post-tensioning and stay cable systems. An extensive experimental study is conducted on a full-scale post-tensioned girder specimen and four large-scale stay cable specimens to evaluate the performance of various NDE methods in detecting location and severity of numerous strand and grout defects. Decision metrics are developed considering multiple criteria such as precision, accuracy, ease of use, inspection requirements, and cost. The decision metrics are intended to facilitate selecting the most appropriate NDE method for assessing a particular defect condition. Overall scores for the tested NDE methods in identifying various defect conditions in different parts of the post-tensioning and stay cable systems are calculated using a weighted sum model. These scores are used to develop a list of ranked NDE methods for evaluating a particular defect condition within a specific location and for a specific duct material.

Use of non-destructive testing methods in a new one-specimen test strategy for the estimation of fatigue data

The comprehensive characterisation of the change in the metallic materials’ microstructure due to an applied load is of prime importance for the understanding of basic fatigue mechanisms or more general damage evolution processes. If they are fully understood, advanced fatigue life calculation methods, which are far away from linear damage accumulation models, can be realised providing even more than only “classic fatigue data”.Within the scope of this paper, it is shown how the potential of non-destructive testing methods, the digitalisation of the measurement techniques as well as signal processing can be combined with a new one-specimen test strategy in order to achieve a gain in information concerning the fatigue behaviour with a simultaneous reduction of experimental effort and costs. The result is therefore not only a considerable advantage with respect to conventional determined Woehler- or S-N-data, but also to established short-term procedures, due to the possibility to separate several material effects by means of data analysis and to use this for fatigue life calculations based on the results of one single specimen.The SteBLife (step-bar fatigue life) approach is a new short-time calculation method developed at the Chair of Non-Destructive Testing and Quality Assurance at Saarland University, which allows to provide S-N-data on the basis of a small number of fatigue tests.For the first investigations in accordance to the new SteBLife approach, temperature measurements by means of an infrared camera were used. The change in temperature is directly related to deformation-induced changes of the microstructure in the bulk material and is considered to represent the actual fatigue state. Within the framework of this paper, the SteBLife procedure was validated on specimens from normalised SAE1045 steel.

Damage evaluation based on ultrasonic testing of compos-ite aircraft elements and image analysis methods

Composite aircraft elements are inspected with the use of non-destructive testing methods to detect the damage appearance and monitor its progression. Ultrasonic testing is one of the most commonly applied methods owing to its capabilities of detecting various types of internal flaws and dam-age as well as evaluating their location and geometrical properties. There are several di culties in analysing the ultrasonic data, which cover the high time-consumption of such analyses resulting from large sizes of the scans and a man-ual handling of them. Thus, due to the possible occurrence of human errors, there is a necessity of increasing the e ciency of these inspections by aiding the analysis of the ultrasonic data. The paper presents proposed methods of the application of image analysis methods for supporting the procedures of the ul-trasonic evaluation of the aircraft structures. These cover facilitating the steps of damage detection, quantification as well as a three dimensional reconstruc-tion and visualisation. The proposed approaches are computationally e cient and may facilitate the data interpretation and damage evaluation procedures.