Non-destructive Diagnostics Research Articles

Detection and Imaging of Debonding in Adhesive Joints of Concrete Beams Strengthened with Steel Plates Using Guided Waves and Weighted Root Mean Square.

Strengthening of engineering structures is an important issue, especially for elements subjected to variable loads. In the case of concrete beams or slabs, one of the most popular approaches assumes mounting an external reinforcement in the form of steel or composite elements by structural adhesives. A significant disadvantage of adhesive joints is the lack of access to the adhesive film for visual condition assessment, thus, there is a need for non-destructive diagnostics of these kinds of connections. The aim of this paper was the identification and visualization of defects in adhesive joints between concrete beams and steel plates using the guided wave propagation technique. The initial theoretical and numerical analyses were performed. The experimental wave field was excited and measured by the scanning laser Doppler vibrometry. The collected signals were processed by the weighted root mean square (WRMS) calculation. As a result, 2-D damage maps were obtained. The numerical simulations were performed to corroborate the experimental results. The results showed that the guided waves could be successfully applied in non-destructive diagnostics of adhesive joints between concrete and steel elements. However, the quality of damage visualizations strongly depended on the location of excitation.

FORUM «TERRITORY OF NDT» 2020

A brief analytical review of the events of the VII International Industrial Forum “NDT Territory. Non-Destructive testing. Tests. Diagnostics” and the “XXII Аll-Russian Scientific and Technical Conference on Non-Destructive Control and Technical Diagnostics” held simultaneously with it. All events were held at the Expocenter Central Exhibition Complex in Moscow. The exhibition of instruments and tools of NK and TD was accompanied by a business program. Within the framework of the forum, round tables were held on topical issues of non-destructive testing and technical diagnostics. The exhibition was attended by more than 57 companies, and information support was provided by a number of news agencies, including the “Spectrum Publishing House” and “RIA Standards and Quality” (“World of Measurement” magazine). In addition to equipment for non-destructive testing and technical diagnostics, modern test equipment, testing and analytical equipment begins to appear on the stands of exhibitors. This year there was a focus on hightech solutions for engineering, metallurgy, oil and gas and other industries. The final of the competition for NK specialists and the award ceremony took place. For the first time, the “Salon of Innovations and Startups 2020” was organized at this Forum, in which representatives of 20 organizations took part. The forum demonstrated a high technical level of non-destructive testing, their metrological support, as well as certification and standardization.

Hankel Transform Application for Calculation of Ring Coils Inductance. Part 1

Electro-acoustic transducers of electromagnetic type are mainly use in modern non-destructive monitoring and technical diagnostics devices of metal products. The influence of a measuring device on parameters of recorded signals, i.e. on the measurement results, can be eliminated if the influence of dimensions of emitters and receivers of alternating magnetic field on the efficiency of generation and reception of elastic waves by the electromagnetic-acoustic method is known in advance. The article is devoted to the development and testing of a method for calculating the inductance of the electrical circuit of ring coils, which are used in electro-acoustic transducers of electromagnetic type. Improvement of computer technology allowed us to apply the methods of integral transformations, which are still considered unsuitable for practical calculations. The new method for calculating the inductance of an electrical circuit located near a conductive ferrimagnet is presented. The solution for the case of a ring coil in vacuum is shown. The reliability of the proposed method is confirmed by the results obtained, which fully correspond to the well-known statement of electromagnetic field in a conductive ferrimagnet.

Nondestructive diagnostics of soluble sugar, total nitrogen and their ratio of tomato leaves in greenhouse by polarized spectra-hyperspectral data fusion.

Polarized spectra–hyperspectral data fusion technique was used to estimate the soluble sugar (SS), total nitrogen (N), and their ratio (SS/N), of greenhouse tomato leaves. Fresh tomato leaves of five different growth stages (seedling, flowering, initial fruiting, mid-fruiting and picking stage) and five different nitrogen treatments (severe stress 25%, moderate stress 50%, mild stress 75%, normal 100%, and excess 150%) at every stage were collected for spectra acquisition and SS and N determination. Polarized reflectance spectra were acquired with a polarization reflectance spectrum spectro-goniophotometer system and four polarization degree features were extracted. Hyperspectral data were collected with a hyperspectral imaging system and four reflectance spectrum features and eight image features were extracted. Initially, models were built with polarization degree features, image features, and spectral features respectively. Linear and nonlinear fusion methods were comparatively used for modeling based on normalized data of the three sources. The results suggest that the performances of SS/N models are better than those of N and SS models, and the prediction capability of the Support Vector Machine (SVM) models of N and SS/N are superior to those obtained with single kind feature. This work indicates that the polarized spectrum-hyperspectral multidimensional information detecting method can feasibly judge the tomato nutrient stress conditions. Multi-features data fusion analysis technique can enhance the prediction accuracy of spectral diagnostics technology in precision agriculture. Keywords: polarized spectra, hyperspectral, soluble sugar (SS), total nitrogen (N), data fusion, tomato leaf DOI: 10.25165/j.ijabe.20201302.4280 Citation: Zhu W J, Li J Y, Li L, Wang A C, Wei X H, Mao H P. Nondestructive diagnostics of soluble sugar, total nitrogen and their ratio of tomato leaves in greenhouse by polarized spectra–hyperspectral data fusion. Int J Agric & Biol Eng, 2020; 13(2): 189–197.

Review of Transverse Beam Profile Measurements Using Synchrotron Radiation

Abstract –Synchrotron radiation (SR) is a tool for non-destructive beam diagnostics since its characters are substantially related to those of the source beam. The spectrum of SR is extremely intense and extends over a broad energy range from the infrared through the visible and ultraviolet, into the soft and hard X-ray regions of the electromagnetic spectrum. The visible light (400 – 800 nm) and X-ray (0.05 – 0.3 nm) regions are used in the beam instrumentation. In the visible light region, transverse beam profile or size diagnostics can be done by an interferometer (light is observed as a wave). Meanwhile, in the submicron beam size measurements, the X-ray SR monitor is commonly used. This paper reports the review of transverse beam profile measurements using SR covering principles and practical experiences with the technique at some accelerator facilities such as Photon Factory, Diamond Light Source, CesrTA, and SuperKEKB. Key words: accelerator, beam instrumentation, transverse beam profile, synchrotron radiation, X-ray, visible light

О решениях обратных задач дифракции звуковых волн

Представлен обзор работ по решению обратных задач рассеяния звуковых волн упругими телами. Теоретические основы решения обратных задач дифракции звука базируются на фундаментальных исследованиях проблемы обратных задач для уравнений в частных производных, выполненных отечественными учеными. В самой общей классификации обратные задачи акустики делятся на обратные задачи излучения (ОЗИ) и обратные задачи рассеяния (ОЗР). При решении задач первого класса по характеристикам звукового поля определяют некоторые параметры излучателя. При решении задач второго класса измерения параметров рассеянного звукового поля используют для идентификации свойств рассеивающего объекта. Большая часть приложений акустических методов основана на решении обратных задач дифракции, когда по параметрам излучаемого или отраженного звукового поля судят о параметрах объекта или среды. Анализ звуковых полей составляет основу методов в гидро- и аэроакустике; исследований в биологии и медицине; неразрушающего контроля и диагностики объектов; ультразвуковой дефектоскопии; обследовании и испытании материалов, конструкций и сооружений. Решения всех обратных задач основаны на решении прямых задач дифракции. В работе представлены наиболее значимые результаты в решении прямых задач рассеяния звуковых волн упругими объектами. Выделены работы, посвященные проблемам обратных задач рассеяния звука неоднородными упругими телами. Это направление составляет предмет интересов в исследованиях авторов.

Rapid determination of spore germinability of Clostridium perfringens based on microscopic hyperspectral imaging technology and chemometrics

The Gram-positive, anaerobic, spore-forming bacterium, Clostridium perfringens (C. perfringens) causes a variety of diseases in humans and other animals. Spore germination is thought to be the first stage of infection by C. perfringens. AGFK, a mixture of l-asparagine, d-glucose, d-fructose, and potassium ions, is an effective nutrient germinant. The objective of this study was to investigate the effects of different AGFK concentrations (0, 50, 100, 200 mM/mL) on C. perfringens spore germination. This paper proposes a novel rapid method for the measurement of spore germinability based on microscopic hyperspectral imaging technology (HSIT). The spore germination rate (Srate), the OD600% and Ca2+-DPA% of C. perfringens were determined by chemical methods under different concentrations of AGFK. The results showed that spores have a maximum germination rate of 94.59% after 80 min with 100 mM/mL AGFK. Microscopic HSIT revealed that the spectral and spatial characteristics of spores varied during the spore germination process. Multivariate analyses (GA-siPLS and GA-PLS) and the gray symbiotic matrix (GLCM) were used to extract highly correlated spectral and spatial descriptors from the time-series data from microscopic HSIT, respectively. Single spectral, spatial signals and data fusion of spectral and spatial information were then used to predict the Srate, the OD600% and Ca2+-DPA % by GA-PLS, respectively. The result show that the Srate calibration was built by GA-PLS using data fusion variables and yielded acceptable results (Rc = 0.96, RMSEC = 0.64, Rcv = 0.93, RMSEP = 0.87, Rp = 0.94). The OD600% optimal model was built by GA-PLS using image variables and yielded acceptable results (Rc = 0.93, RMSEC = 19.36, Rcv = 0.91, RMSEP = 24.36, Rp = 0.89). For Ca2+-DPA %, the model based on the fusion of spectral and imaging data was optimal. The Ca2+-DPA % calibration yielded acceptable results (Rc = 0.95, RMSEC = 49.83, Rcv = 0.93, RMSEP = 58.98, Rp = 0.92). This work demonstrates the potential of microscopic HSIT for the non-destructive detection of spore germinability. The data fusion models also significantly improved the prediction of spore germinability. In conclusion, microscopic HSIT exhibits considerable promise for nondestructive diagnostics of spore germination.

EQUIPMENT AND DEVICES AT THE EXHIBITIONS "TESTING & CONTROL" AND "NDT RUSSIA – 2019"

A brief information review of the 16th International Exhibition of Testing and Measuring Equipment «Testing & Control» and the 19th International Exhibition of Non-Destructive Testing Equipment «NDT Russia» which took place from October 22 – 24, 2019 at the Crocus Expo IEC in Moscow is presented. Russian and foreign manufacturers and suppliers demonstrated a wide range of equipment in the following areas: testing equipment, measuring and metrological equipment, equipment for production control, machine vision, equipment for non-destructive testing and technical diagnostics, equipment for laboratory control, diagnostic and monitoring systems. The All-Russian Scientific Conference “Measurements. Tests Control” was held simultaneously with the exhibitions. It was devoted to methods, tools, metrological support of research, testing and operation of products in various industries.

Method for express diagnostics of resonant properties of wood aged in buildings

New method and technical solutions for nondestructive express diagnostics and targeted selection of spruce wood with unique dendro-acoustic properties aged in buildings are presented. Flow charts of equipment and ways of its application to identify resonant properties of wood in different parts of a building, including the walls made of round timbers, ceiling and floor boards are given. The proposed ways of wood quality diagnostics in buildings has its advantages over conventional methods.

Nondestructive diagnostics of soluble sugar, total nitrogen and their ratio of tomato leaves in greenhouse by polarized spectra–hyperspectral data fusion

Nondestructive diagnostics of soluble sugar, total nitrogen and their ratio of tomato leaves in greenhouse by polarized spectra–hyperspectral data fusion

Algorithm for Integrated Non-Destructive Diagnostics of Technical Condition of Structures of Buildings and Constructions Using the Thermogram Analysis

An algorithm for integrated non-destructive diagnostics of technical condition of structures of buildings and constructions using the temperature field analysis is proposed. An attempt is made to systematize, characterize and build a logical sequence of stages for energy inspection of heat-consuming and heat-generating construction objects and their structural elements. The presented algorithm differs from the well-known technologies for energy monitoring of buildings and structures by the presence of two additional steps, which are an integrated part of any energy examination: determination of the relative surface humidity of building structures and the actual mass flow of coolant through a heating system using qualitative and quantitative assessment of thermal images. The implementation of energy (thermal imaging) and technical examinations according to the presented structural scheme requires appropriate equipment, as well as involvement of highly qualified specialists (civil engineers, thermal power engineers, thermal physicists, thermal imaging operators, etc.).

Reliability Improvement of Printed Circuit Boards by Designing Methods for Solder Joint Technical Diagnostics with Application of Acoustic Emission Method

The paper represents technical diagnostics of printed circuit boards in particular their solder joints performed by commonly used through-hole and surface mount technologies. Operation and technology cause mechanical interactions and forces between substrate of printed circuit board and electronic components. Such tensile, shear, bending or torque forces transmit through the contact joints, which appear to be the weakest links in the assembly. The experimental research was conducted by mechanical tensile and pure bending tests followed by using method of acoustic emission. Conducted tests demonstrated considerable sensitivity and applicability for the method of acoustic emission to detect defects and possibly to assess the ultimate strength of solder joints in nondestructive diagnostics performed under forces long before the final failure. In order to minimize errors while measuring small loads in tensile tests of ceramic capacitors the special appliance was designed. The experiment was conducted to verify the overheating effect to ultimate load of the solder joints. Surface mount technology for ceramic capacitors has been optimized by introducing high temperature preheating mode that improves adherence to the contact pads and increases tensile strength, what was also confirmed by acoustic emission analysis. The pure bending appliance was designed to provide instant monitoring of all solder joints by equal testing stress. By conducted pulsing test cycles the total count was identified as the most informative parameter of acoustic emission that correlates with types of defects and ultimate strength of the solder joints. The planar location model has been developed by the idea of remote detection of acoustic emission through the volume of homogeneous medium such as water, unlike detecting acoustic emission on the surface of printed circuit board where acoustic emission signal is likely to be distorted or even lost. Using method of acoustic emission and pure bending cycling test the method for technical diagnostics of solder joints has been designed. The results represented in the paper contribute to design and technology improvement in radio-electronics.

Preload monitoring in a bolted joint using Lamb wave energy

The knowledge of the load in prestressed bolted connections is essential for the proper operation and safety of engineering structures. Recently, bolted joints have become an area of intensive research associated with non-destructive diagnostics, in particular in the context of wave propagation techniques. In this paper, a novel procedure of bolt load estimation based on the energy of Lamb wave signals was proposed. Experimental tests were performed on a single lap joint of two steel plates. Ultrasonic waves were excited and registered by means of piezoelectric transducers, while precise measurement of the bolt load was obtained by means of using the force washer transducer. Experimental tests were supported by the finite element method analysis based on Schoenberg’s concept. The results showed that the relationship between the bolt load and signal energy was strongly nonlinear and it depended on the location of acquisition points.

Sonic and Impact Test for Structural Assessment of Historical Masonry

Diagnostics is a very important tool of knowledge in the field of historical buildings. In particular, non-destructive techniques allow to deepen the study of the mechanical characteristics of the historical walls without compromising the artistic value of the monumental building. A case study of the use of sonic and impact tests was described, performed using the same instrumented hammer, for the characterization of the masonry walls at the Sanctuary of Santa Maria delle Grazie at Varoni, one of the churches damaged in the 2016 Amatrice earthquake. Sonic tests showed the presence of a discontinous masonry texture, as well as confirming the ineffectiveness of the strengthening work made by injections of lime mortar. The impact test allowed us to obtain the elastic modulus of the omogeneous stones of the masonry. The results obtained from the non-destructive techniques were confirmed by the flat jacks test carried out on the building, confirming the great potential of the non-destructive diagnostics suitable for analyzing important structural parameters without affecting the preservation of historical masonry structures.

Nondestructive diagnostics of magnesium deficiency based on distribution features of chlorophyll concentrations map on cucumber leaf

A new and nondestructive method for diagnosing magnesium (Mg) deficiency based on chlorophyll concentration distribution features of cucumber leaves was proposed. Mg deficient cucumber plants and Control plants were grown under non-soil conditions with special nutrient supply. Cucumber leaves were employed to collect hyperspectral images using a visible and near infrared (VIS/NIR) hyperspectral imaging system (400–900 nm) and determine reference chlorophyll concentrations using high performance liquid chromatography (HPLC). An optimal chlorophyll concentration calibration model (Rp = 0.9087) was constructed and used to detect chlorophyll distribution maps of Mg deficient leaves and Control leaves. Results shown that chlorophyll content distributed more unevenly on Mg deficient leaves than Control leaves. The Standard Deviation (SD) value of the chlorophyll content at all the pixels on a chlorophyll distribution map was calculated for Mg deficient diagnostics. An Mg deficiency diagnostics model with satisfied performance (diagnostic rate 93.33%) was obtained. The result indicated the SD value of chlorophyll concentrations on the whole cucumber leaf could be employed to diagnose Mg deficiency nondestructively.

Modern european methods of non-destructive diagnostics of bridge structures

Introduction. Various existing methods of non-destructive diagnostics, in particular for diagnostics of bridge structures are analyzed. However, nowadays in different countries of the world the researches are under way on the search for the most informative methods of non-destructive diagnostics of building structures, facilities, in particular bridge structures, which would enable to receive reliable data on the processes occurring in the structures under the influence of various factors. Problem Statement. Existing methods of non-destructive diagnostics which are used for the diagnostics of bridge structures basically consist in periodic placement of sensors on structures. Having gathered information, the sensors are dismantled. Such actions are repeated as the time of the next inspection comes. In addition, measurements are fulfilled only at the discrete points, as the most devices and equipment have a limited operating range of measurements. The small amount of data received and the long interval between their acquisitions cannot provide signaling about the inevitable disaster that may be caused by various impact factors. Purpose. The ultimate goal of the international scientific organization FEHRL, within the framework of which the SENSKIN Consortium works, is to develop a system for monitoring bridge structures in the framework of the international research project «SENSKIN» – «Sensing Skin for monitoring-based maintenance on the transport infrastructure». Conclusions. Participants of the project «SENSKIN», including «DerzhorNDI» SE as a Consortium member, developed the sensors that will collect information on bridges, power supplies, data transmission and processing modules, software and other components of the bridge structure monitoring system. At this stage, the prototype of the monitoring system has been tested on the full-scale objects. Current information on the monitoring system can be found on the website of the SENSKIN Consortium http://www.senskin.eu. For more reliable operation of non-standard bridges (the bridges which parameters exceed the limit values according to the adopted classification of bridges) in Ukraine, it is necessary to plan the transition to monitoring of bridge structures using the systems that would enable the acquisition of the necessary information about the state of structures in the event of catastrophic situations that will allow avoiding, in particular, the death of people.

Modern european methods of non-destructive diagnostics of bridge structures / Сучасний європейський метод неруйнівної діагностики мостових конструкцій

Introduction. Various existing methods of non-destructive diagnostics, in particular for diagnostics of bridge structures are analyzed. However, nowadays in different countries of the world the researches are under way on the search for the most informative methods of non-destructive diagnostics of building structures, facilities, in particular bridge structures, which would enable to receive reliable data on the processes occurring in the structures under the influence of various factors. Problem Statement. Existing methods of non-destructive diagnostics which are used for the diagnostics of bridge structures basically consist in periodic placement of sensors on structures. Having gathered information, the sensors are dismantled. Such actions are repeated as the time of the next inspection comes. In addition, measurements are fulfilled only at the discrete points, as the most devices and equipment have a limited operating range of measurements. The small amount of data received and the long interval between their acquisitions cannot provide signaling about the inevitable disaster that may be caused by various impact factors. Purpose. The ultimate goal of the international scientific organization FEHRL, within the framework of which the SENSKIN Consortium works, is to develop a system for monitoring bridge structures in the framework of the international research project «SENSKIN» – «Sensing Skin for monitoring-based maintenance on the transport infrastructure». Conclusions. Participants of the project «SENSKIN», including «DerzhorNDI» SE as a Consortium member, developed the sensors that will collect information on bridges, power supplies, data transmission and processing modules, software and other components of the bridge structure monitoring system. At this stage, the prototype of the monitoring system has been tested on the full-scale objects. Current information on the monitoring system can be found on the website of the SENSKIN Consortium http://www.senskin.eu. For more reliable operation of non-standard bridges (the bridges which parameters exceed the limit values according to the adopted classification of bridges) in Ukraine, it is necessary to plan the transition to monitoring of bridge structures using the systems that would enable the acquisition of the necessary information about the state of structures in the event of catastrophic situations that will allow avoiding, in particular, the death of people.

Non-destructive diagnostics of steel-reinforced concrete structures: detecting and locating reinforcement

The paper describes the possibilities of non-destructive determination of the location and depth of reinforcement in concrete structures using electromagnetic cover meters. It is currently one of the most popular methods for determining the location, cover depth and diameter of reinforcement. However, there are not many sources that would give a detailed description of specific measurement results. This paper describes the use of the Profometer PM-630 cover meter for in-situ measurement of a steel-reinforced-concrete road bridge deck. The paper details the results of measurements of cover depth, bends in reinforcement, and discusses the strong and weak points of the method.

Magnetic-Noise Diagnostics

The influence of the ambient temperature and the thickness of the paint coating on the magnetic-noise parameters is investigated, in the diagnostics of steel structures. It is shown that nondestructive magnetic-noise diagnostics may be used to monitor the state of load-bearing structural elements in situ at any temperature, in extreme conditions.

Study of the strained state of steel plates of small thickness using coercimetry

The results of studying the strain state and depth of dents in K08Yu low-carbon steel plates of small thickness (3-5 mm) using the method of coercimetry are presented. It is known that mechanical stresses and strains that occur in steel rods and base metal of oil and gas pipes have a significant impact on the magnitude of the coercive force (CF) near the sample surface. The effect of plate deformation and geometric dimensions of the dents on the CF magnitude is analyzed using a KM-445.1 coercimeter and tools for stepwise determination of the depth of dents (calipers with a depth gauge, tape measures, metal strip, marker). The calculated differential dependences linking the curvature of the plate with the dent depth are obtained. The intensity of linear strains occurring in the plate is determined. The relations between the coercive force and strain characteristics of plates with different types of collapsing are determined, namely, it is shown that in a plate with a single dent, the value of the coercive force increases monotonically with the depth and intensity of deformations, whereas in a plate with a double dent, there is a complex wave-like dependence of the coercive force magnitude on the depth and intensity of deformations with a characteristic inflection point and the character of the dependence provides a possibility for determination of the size and type of the dent. The proposed analysis of the stress state using the method of coercimetry makes it possible to detect geometric imperfections on the surface of the plates and carry out their non-destructive diagnostics.