Non-destructive Control Method Research Articles

On Raman scattering cross section ratio of amorphous to nanocrystalline germanium

Raman scattering spectroscopy is powerful, express and non-destructive method for control of phase composition of different materials. To determine the crystalline part, one should know the ratio of Raman cross sections of crystalline to amorphous phases. In this Letter we report on accurate comparative measurements of the Raman scattering from monocrystalline and nanocrystalline Ge, as well as from amorphous Ge films. Being accompanied by the respective optical transmittance/reflectance measurements, these data allowed us to estimate the integrated Raman scattering cross section ratios of monocrystalline and nanocrystalline Ge to amorphous Ge, for the first time. For monocrystalline Ge the obtained ratio is equal to 4, while for nanocrystalline Ge this ratio decreased monotonously with a decrease of the nanocrystal sizes. Some physical reasons of the experimentally observed dependence are proposed.

Concept of a new method for continuous non-destructive control of asphalt road pavements compaction

The article deals with the research results of a concept for a new method of continuous non-destructive control of asphalt road pavements compaction based on the analysis of the vibration and force state of working bodies of road construction machines as well as the corresponding algorithm for data conversion and intelligent prediction of compaction quality. The definition of the concept “cyber-physical road construction system” is proposed. A scientific problem as well as the corresponding purpose and objectives of the study are formulated. The theoretical background of the continuous compaction control method for pavers is considered. The structure of the considered cyber-physical road construction system is determined.

Stress-strain state of concrete element with damage

Problem statement. At present, it is relevant to determine the technical condition of structures and their strengthening as needed. Damage of structures affects the process of determining the physical and mechanical characteristics of concrete structures. Purpose. To determine the effect of structural damage on the stressed state of the structural member. To perform calculations and obtain fields of stresses, strains and displacements at different model parameters and stress levels. The technique. The research has been performed on structural models using software systems "LIRA SAPR". A structural model having dimensions of 100 × 100 × 400 mm was used for the study. Materials of concrete C16/20, C18/22.5 and C20/25 with corresponding properties have been used. The structural damage was modeled by sequentially removing one of the five elements from the experimental model. The calculations were performed for models with one and two defects in the design. For the experimental model with two defects, the grooves were arranged in parallel. The load parameters for modeling the deformation process varied within 0.1…0.5 of the limit stress. Results. Analysis of the results of the study shows that the change in stress in the area adjacent to structural damage is affected by the size of this area, the level of stress-strain state in the structural element and the relationship between the sizes of adjacent structural elements; Zero voltage zones may appear on the surface of the structural member; it is necessary to take into account the level of stress-strain state when assessing the physical and mechanical characteristics of concrete using non-destructive methods of control in the area affected by existing structural damage.

Experimental static and dynamic response of RC beams damaged and strengthened with NSM GFRP rod

Inserting FRP rods into grooves using the NSM technique has been demonstrated to be a suitable method for repairing reinforced concrete (RC) beams. There is limited experience with the use of GFRP in the strengthening of RC elements due to low Young’s modulus of glass fibers. The aim of the paper is to analyse the static and dynamic behaviour of RC beams damaged and strengthened by glass fiber reinforced polymer (GFRP) rods utilizing the near surface method (NSM). Undamaged and damaged three RC beams have been experimentally tested under bending loading with and without strengthening by GFRP rods. For a beam, damage has been represented firstly by notches on concrete cover. The beam has been successively strengthened by epoxy resin and NSM GFRP rod and then subjected to bending tests. Vibration tests have been adopted as nondestructive method of control during the experiments to assess the response of RC beams at different damage steps of concrete or due to decrease of bond of GFRP rod. Vibration tests foresaw two boundary conditions, respectively, free-free and hinged ends. Experimental static and vibration results are below shown; discussion and comments on the strengthening bond of NSM GFRP rod have been developed.

Brief destructions of basic nodes of excavators and critical size of cracks

The article studies brittle fractures of metal structures of mine and hydraulic excavators basic units. Based on the data analyzed and physics of the brittle fracture process, recommendations are given to improve the reliability of machines. For the analysis of brittle fractures, statistical data on machine failures under the conditions of the Korshunovsky GOK and ALROSA quarries were used. The approach to the control of nucleation and formation of brittle fractures by non-destructive methods, which substantially reduces the costs of repair works is described. The analysis of brittle fractures of mining excavators basic units revealed general patterns of destruction causes. Accurate identification of brittle fractures requires simplification of repair works. The method of nondestructive control of machines should be applied. The non-destructive control method is used to control the a brittle cracking in advance and eliminate during scheduled repairs. The scheduled identification and elimination of cracks reduces laboriousness of repair and recovery operations of large-sized units and aggregates of excavators.

INFLUENCE OF TOOL TILT ANGLE ON THE PROCESS CHARACTERISTICS OF FRICTION STIR WELDING

The article is devoted to the one of the features of choosing the technical parameters of regime of friction stir welding. The tool tilt angle is the object of research. This parameter underlies the mechanism of the formation of welding joints. The methodology and the experiment’s results of determining the influence of the tool tilt angle from the power and thermal characteristics of the process of friction stir welding are presented in this work. Also there is a presentation of the results of the welded joints’ studies which were done by the non-destructive and destructive methods of control. The dependency of the tool tilt angle from the power and the temperature in the welding zone is defined on the basis of the received results.

Оптимизация параметров газогенераторной и лидарной систем для измерения потоков воздуха при неразрушающем контроле качества охлаждающих микроканалов на малых расстояниях

The paper describes a method of non-destructive quality control of manufacturing ventilating pinholes by measuring the speed of an expiring aerosol-containing air flow using a coherent continuous lidar. A mathematical model is developed, with the help of which the optimal values of the parameters of the gas-generating and lidar systems are determined. The effect of the diameter of aerosol particles on the backscattering power is investigated.

The logistics network digital twin in view of concept of the non-destructive quality control methods

The purpose of the research consists in improving the theoretical basis for non-destructive quality control methods in the context of digitalization and an active transition to Industry 4.0. The methodology used by authors include the consideration of the logistics network digital twin, as well as globalization of markets and ever-increasing global competition in all areas. The article discusses non-destructive quality control methods based on the process of modeling digital twins and the authors’ approach proves the advantages of just such an innovative concept of expanding the definition of logistics network digital twin in comparison with the traditional methods of non-destructive quality control. It could be shown that this approach eventually leads the ability of industries to switch to digitalization of their processes. Saying precisely the improving of the quality control methods could be treated as digitalization of their supply chains, reflecting the entire product life cycle. We have displayed a digital supply chain, which includes the method of non-destructive testing, like a digital twin. The main difference between the digital supply chain and the traditional supply chain is noted. The ideas of large audit companies such as Gartner’s, Siemens and Deloitte are analyzed. What are the benefits of using a digital twin as a non-destructive testing method? All participants of this digital supply chain receive their benefits in terms of digitalization and market competition.

Thermal Method for Non-Destructive Control of Actual Coolant Mass Flow through a Heating Device

The studies show that expenses for heating buildings and structures account for more than 60% of total utility costs in the Russian Federation. Therefore, the issues on energy and resource conservation and improving the energy efficiency of construction projects for various purposes are relevant and priority. Infrared thermography is actively used during examination of thermomechanical equipment, building structures, external and internal engineering systems and their elements. Heat monitoring makes it possible to avoid significant costs for dismantling of controlled objects and to localize the thermal defects found during the inspection stage, thereby reducing costs of repair works. The article considers and analyzes the existing options for the quantitative analysis of thermograms. The authors propose a new method for quantitative processing of thermograms, aimed at assessing the operation of heating devices in heating systems of buildings and structures. The essence of thermal non-destructive testing technique is to determine the actual mass flow rate of coolant through the heating device.

Choosing and Explaining Methods of Non-Destructive Control of Gear Mechanisms in Imported Excavators

Kuzbass opencast coal mines use foreign produced excavators as basic equipment. Capital repair of these excavators involves complete replacement of all tooth wheel gearing in reduction gear boxes after 2~3 years of work (depending on operating time). The cost of this replacement is practically equal to the cost of new gear boxes. To minimize repair costs and extend service life of gear-tooth systems in gear boxes a methodology for monitoring technical state of gear boxes in imported mining equipment was developed. It allows to obtain reliable information about the level and significance of in-service defects in their elements. The research showed that the most reliable methods of control are visual and dimensional test (67%) and fluorescent-magnetic inspection (32%), and used together these two methods allow to detect up to 100% of significant defects. The most significant among service defects in typical elements of gearing systems are single and multiple cracks.

Классификация современных методов неразрушающего контроля. Возможность их применения для диагностики оборудования нефтегазовой отрасли

Классификация современных методов неразрушающего контроля. Возможность их применения для диагностики оборудования нефтегазовой отрасли

Research of plywood quality by acoustic methods

Traditionally, for composite materials, glued wood and solid wood are used nondestructive methods of control that take into account the specific features of the object. Plywood is a non-metal anisotropic material of complex structure, so most non-destructive testing methods, such as magnetic and eddy current methods are excluded. For choosing a method, it should also be borne in mind that plywood is a large product and may have significant size defects. The shock method is easier to implement than other non-destructive testing methods, so it can be considered effective for plywood defectoscopy. The existing classical shock method is carried out by the absolute values of the deviations of the characteristics of the oscillatory processes of the plywood. Changing the variable factors of plywood may reduce the accuracy of the device being implemented. Therefore, a technique for improving the shock method by measuring the relative characteristics of the oscillation process was developed. Comparison with the known, most accurate ultrasonic method of control revealed that the highest correlation with ultrasound has such a parameter of the shock sensor as the coefficient of harmonic distortion, which gives reason to recommend the shock method for determining the area defect plywood.

Heat Transfer in the Formation of Thermoelastic and Thermoelectric Responses of Metals to Laser Pulse Action

We analyze the effect of heat transfer in metals on parameters of the thermoelastic and thermoelectric responses of metals to a pulsed laser action. It is shown that two-stage analysis of the dynamic problem of thermoelasticity and the thermoelectric effect makes it possible to obtain an adequate description of experimental results. The results described here demonstrate a considerable dependence of the response parameters on the microstructure, which indicates the possibility of development of a high-efficiency method of nondestructive control of metal quality.

MATHEMATICAL MODELING OF ROLLER WEAR

In the given work the method of noise-acoustic non-destructive control during carrying out of diagnostics of bearings of rolling of mats of wheels of cars is considered. The proposed non-destructive method of control provides an opportunity to check the efficiency of the selected lubricant, thereby increasing the life and performance of the bearings. A laboratory installation for the diagnosis of roller bearings has been created, which allows to obtain their acoustic parameters depending on the load of the bearing unit, the time of application and application of different types of lubricants in bearings. The mathematical model developed by the authors is aimed at determining the degree of wear of bearing shafts and allows them to predict their possible work life based on the received noise-acoustic parameters.

Research of Road Pavement Survey Process Using Georadiolocation

The authors of this paper carried out a survey of road pavement and analyzed the need for such survey. The research was conducted using an operating facility as an example. In this paper, the decisions are grounded, the survey stages are described. Mobile methods of non-destructive control for road structures diagnostics are of particular importance at the moment. As a part of this research, the tasks related to determining the thickness of structural layers, the uniformity of materials, and the detection of voids under the auto-road surfacing were solved. The results of diagnostics and quality control of road-building works, as well as georadiolocation (GPR) technologies, are considered in detail. The results of tests of different GPR models and the economic efficiency of their use in road industry are described. The test results are illustrated with radarograms. The result of the GPR study of an auto-road section is presented. The results of the work showed that GPR research methods as a part of the survey allow reasonably planning and carrying out measures to eliminate and prevent various types of subsidence and road surfacing destruction, as well as to assess the nature and extent of the negative processes development. With the timely elimination of these problems, major damage and subsequent costly repairs can be avoided. Having compared the most significant factors, the authors make the conclusion that the method under research has got advantages, which are high efficiency and high capacity.

APPLICATION OF ACTIVE THERMOGRAPHY FOR DEFECTOSCOPY OF TECHNOLOGICAL EQUIPMENT ON OBJECTS OF THE NUCLEAR POWER PLANTS

The methodical and physical bases of the use of active thermography as a high-performance non-destructive method of control and defectoscopy of materials during thermovision monitoring of technological equipment at NPP objects are considered. The data of experimental research confirm the efficiency of the use of thermal and low-frequency electromagnetic activators in the thermographic defectoscopy. The features of the application of dynamic thermography and the influence of external activation sources on the thermal appearance of structural inhomogeneities and defects in materials are investigated. It is shown that the application of special methods of processing thermal images that take into account the amplitude-frequency and morphological features of thermoanomalies, allows to control the thermal display of energy-absorbing structures and defects, provide the possibility of their identification against the background of false thermoanomalies.

Control of defects in layer composite materials by the method of electromagnetic emission

The article considers the method of non-destructive quality control of layered composite materials based on registration and spectral analysis of electromagnetic radiation of piezoactive adhesive joint and cavitation acoustic noise. The method allows the diagnostics of adhesive compound defects of layer composite materials with 50 [%] accuracy and 0.7 confidence level. The spectrum of electromagnetic radiation of the adhesive compound shows defects at the layered boundary. The use of active piezoelectric layer of elastomer adhesive joint increases adhesion strength at stratification by 2.1 – 5.2.

Determination of the reliability of control of curved surfaces by eddy current transducer

The questions about metrological assurance and evaluation of the reliability of decision-making on the state of a metal control object during eddy current testing of surfaces with complex structure are considered in this article. The target of the research is the complex surfaces from position of their geometry and electromagnetic characteristics, that are formed on the surface of metal products during the formation of welded joints.During the quality control of state of welded joints, first of all, the special attention is given to the identification of internal and external defects of the joint weld. However, the quality of the joint weld, from position of its mechanical characteristics, is no less affected by the shape, size and composition of the joint weld. The task of controlling the size and shape of the joint weld is quite successfully solved by applying the visual-optical method of nondestructive control. With regard to composition of the joint weld, the eddy current method of control allows to determine the composition of the material of the welded joint by measuring the magnetic and electrical characteristics of the metal.The use of eddy current method of control allows to determine the geometrical parameters of a metal object and its electromagnetic characteristics. However, in this case, the uncertainty appears that is associated with the impossibility of determining which of the factors (the geometric dimensions of the object of control or the change in its electromagnetic characteristics), to some extent, has affected the measurement result of the signal of the eddy current transducer.This article analyzes the influence of these factors from the point of view of their metrological characteristics and provides the formulas that allow to estimate the risks of the customer and the executor in the case of control of complex surfaces by the eddy current method.

Nondestructive Control of Diffusivity in Uniaxially Reinforced Porous-Material Products

A modification is considered of the pulse method of nondestructive control of diffusivity to ensure the possibility of its use to investigate uniaxially reinforced porous material products that are characterized by significant anisotropy of properties. Results are presented of the selection of design parameters of a measuring device and operating conditions of the process of measuring the required diffusivity that ensure an increase in the efficiency and accuracy of the applied method of nondestructive control.

Integrated Approach to Determine Operational Integrity of Crane Metal Structure

One of the elements limiting the crane life cycle and affecting the safety of its operation is a metal structure. Currently, there is no single scientifically-based approach to assess the operational integrity of crane metal structures. The paper deals with issues related to the development of an integrated approach to determine the operational integrity of crane metal structures, based on a combination of numerical methods of calculation (the finite element method and boundary states calculation) and magnetic coercive non-destructive control. The research of the influence of the metal chemical composition, its microstructure and the controlled elements thickness on coercive force values have been carried out. In order to take into account these parameters, it is suggested to use certificated experimental samples with variable cross sections. The practical value of the research is to apply the integrated approach that will eliminate the disadvantages of a separate method, complement these methods, increase the objectivity and accuracy of determining the operational integrity of crane metal structures.