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1

Digital Image Correlation - method development, scope, principle of functioning, and future goals

Kempny Marcin

Journal of Metallic Materials

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2022

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Vol. 74, no. 3-4

30--41

EN

This paper presents the basics of the Digital Image Correlation System, its algorithm of operation, methods of data recording and implementation. In addition, the paper characterises in detail the standard bench instrumentation necessary for the implementation of this type of measurement. The paper also describes the procedure of sample preparation and classifies the main methods of applying a marker to the surface of the sample. The article highlights the main advantages of the system and the main difficulties associated with its operation, and indicates the important parameters affecting the quality of the measurement. The paper shows a wide range of applications of Digital Image Correlation (DIC) and the possibilities of cooperation with other measurement systems as well as extended versions of the system, such as Digital Volumetric Correlation. The article also outlines further directions for the development of the DIC research methodology including, among others, extending the temperature range in which the method can be applied, as well as increasing the speed of camera image recording. Such modifications will allow the image correlation method to be used for research where it has not yet been possible.

PL

W pracy przedstawiono podstawy systemu cyfrowej korelacji obrazów, algorytm działania, metody rejestracji danych oraz implementacji. Ponadto w pracy szczegółowo scharakteryzowano standardowe oprzyrządowanie stanowiskowe niezbędne do realizacji tego typu pomiarów. W pracy opisano również procedurę przygotowania próbki oraz sklasyfikowano główne metody nanoszenia znacznika na powierzchnię próbki. Artykuł podkreśla główne zalety systemu, główne trudności związane z jego działaniem oraz wskazuje istotne parametry wpływające na jakość pomiaru. Manuskrypt pokazuje szeroki zakres zastosowań cyfrowej korelacji obrazu (DIC) oraz możliwości współpracy z innymi systemami pomiarowymi, a także rozszerzone wersje systemu, takie jak cyfrowa korelacja wolumetryczna. W pracy nakreślono również dalsze kierunki rozwoju metodologii badań DIC, w tym m.in. rozszerzenie zakresu temperatur, w których metoda może być stosowana, jak również zwiększenie szybkości rejestracji obrazu z kamer. Takie modyfikacje pozwolą na wykorzystanie metody korelacji obrazów do badań, w których zastosowanie DIC nie było dotychczas możliwe.

2

Quality analysis of the mechanical lever and improvement of non-destructive testing process

Siwiec Dominika, Pacana Andrzej, Dwornicka Renata

System Safety : Human - Technical Facility - Environment

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2020

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Vol. 2, nr 1

299--306

EN

The analysis of product quality is an indispensable action in developing enterprises. In case of mechanical products, the non-destructive tests (NDT) are effective way to make control. Non-destructive tests allow making assessing product quality with-out destroying it. Due to the dynamically growing requirements of customers and necessary, the improvement actions for demanding organizations important is to make a complex analysis of quality products. Such an action was proposed to a production and service company located in Podkarpacie region of Poland. The aim was to analyze the quality of the mechanical lever and improvement the process of non-destructive tests, in order to identify the source of nonconformity with using quality management techniques. These activities were to demonstrate that the sequence (NDT and selected quality management techniques) would allow the detection of unconformities on the product surface and also identify the source of this unconformity. In the enterprise, the quality research of the product using fluorescent and magnetic-powder methods was made. After identified the unconformity on the product the additional actions which could point the source of unconformity were not practicing. The proposition of improvement in the NTD was use appropriately selected quality management techniques (Ishi-kawa diagram and 5Why method) after identified the unconformity. The mechanical lever was tested, which its surface using the magnetic-powder method was analyzed. After identified unconformity (scratch) using the Ishikawa diagram, the potential causes were identified and four main causes were selected (i.e.: uncleaned pattern, impurities during production, poor molding mass, poorly carried out product production method). It has been shown that sequence of NDT, Ishikawa diagram and 5Why method allows to identify the unconformity on product surface and source its creation. This sequence could be practicing to analyze other product in production and services enterprises.

3

Determination of the strength parameters of pinewood based on the non-destructive sclerometric test with a wood hammer

Szostak Bartosz, Trochonowicz Maciej, Kowalczyk Mateusz

Civil and Environmental Engineering Reports

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2020

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Vol. 30, no. 1

43--52

EN

To assess the technical condition of a structure and design it using existing elements, it is necessary to know its parameters. For existing facilities, it is often not possible to get a sample of material and examine it directly in the laboratory. For this reason, in situ nondestructive testing is very important. The main goal of the paper is to present the issues related to determining the strength parameters of a particular wood based on the non-destructive sclerometric test performed with a wood sclerometric hammer. The study also presents the results of the impact of pinewood density on its compressive strength.

4

Types of Surface Impurities versus the Quality of Brazed Joints

Tomków J., Haras J.

Biuletyn Instytutu Spawalnictwa w Gliwicach

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2018

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Vol. 62, No. 4

53--48

EN

Brazing is one of the primary joining processes increasingly often applied in industry. Because of their mechanical properties, overlap joints are particularly popular when making brazed structures. The use of brazed joints in structures of critical importance requires that particular attention be paid to joint quality, e.g. by the appropriate cleaning of surfaces to be joined. The article presents results of non-destructive tests of brazed joints made in steel S235JRG2. Surfaces used in the tests were deliberately contaminated to simulate the presence of welding imperfections. Afterwards, the test specimens were subjected to non-destructive (visual and radiographic) tests aimed to determine the effect of surface impurities on the quality of brazed joints.

PL

Lutowanie twarde jest jednym z podstawowych procesów spajania stosowanym coraz szerzej w przemyśle. Ze względu na własności wytrzymałościowe często wykorzystuje się złącza zakładkowe. Zastosowanie połączeń lutowanych na odpowiedzialne konstrukcje determinuje konieczność szczególnego dbania o jakość złączy m.in. przez odpowiednie oczyszczenie łączonych powierzchni. W pracy przedstawiono wyniki badań nieniszczących połączeń lutowanych na twardo ze stali S235JRG2. Niektóre z łączonych powierzchni celowo zanieczyszczono dla wywołania obecności niezgodności lutowniczych. Próbki poddano następnie badaniom nieniszczącym (wizualnym oraz radiograficznym), których celem było określenie wpływu zanieczyszczenia powierzchni na jakość złączy lutowanych.

5

Evaluation of the Effectiveness of Low-Density Couplants in Ultrasonic Tests

Krawczyk R.

Biuletyn Instytutu Spawalnictwa w Gliwicach

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2018

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Vol. 62, No. 4

17--24

EN

The article presents the analysis of the effectiveness of acoustic feedback required in ultrasonic contact tests. The analysis included low-density couplants, the use of which aimed to provide the most effective transfer of the beam of ultrasonic waves from the probe to an element subjected to an ultrasonic test. The tests were performed using a normal probe emitting longitudinal waves and an angle probe emitting shear waves. The tests involved the use of standard specimens as well as steel specimens having various test surfaces.

PL

Przedstawiono analizę skuteczności sprzężenia akustycznego wymaganego w badaniach ultradźwiękowych kontaktowych. W analizie uwzględniono środki sprzęgające charakteryzujące się małą gęstością mające na celu jak najskuteczniejsze przeniesienie wiązki fal ultradźwiękowych z głowicy do elementu badanego. Badania przeprowadzono głowicą normalną fal podłużnych i kątową fal poprzecznych na próbkach wzorcach oraz próbkach stalowych o różnych rodzajach powierzchni badania.

6

Analysis of Low-Amplitude Indications in Ultra-sonic Tests of Thick-Walled MAG-Welded Butt Joints

Krawczyk R.

Biuletyn Instytutu Spawalnictwa w Gliwicach

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2018

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Vol. 62, No. 6

17--25

EN

The article presents an attempt at the clarification of low-amplitude indications, i.e. below the level of assessment, frequently detected in ultrasonic tests of welded joints. The above-named indications, non-evaluable in accordance with requirements of related standards used in ultrasonic tests, are often present in MAG-welded joints. The attempted clarification of the above-named exemplary indications required the performance of tests involving thick-walled MAG-welded butt joints.

PL

Przedstawiono próbę wyjaśnienia wskazań o małej amplitudzie, tj. poniżej poziomu oceny, ujawnianych dość często w badaniach ultradźwiękowych złączy spawanych. Takie wskazania niepodlegające ocenie zgodnie z wymaganiami norm przedmiotowych stosowanych w badaniach UT często występują w połączeniach spawanych metodą MAG. Próbę wyjaśnienia takich przykładowych wskazań przeprowadzono na grubościennych złączach doczołowych spawanych metodą MAG.

7

Indirect measure of corrosion level based on crack opening

Bossio A., Montuori M., Bellucci F., Lignol G.P., Protas A., Cosenza E., Manfredir G.

Wiadomości Konserwatorskie

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2013

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Nr 34

36--40

EN

Reinforced concrete (RC) is a widely used material since about 100 years. The early degradation of RC structures has led to intervene on them. Main causes of degradation are carbonation, chlorides and sulphides attacks. Even if diffusion of RC structures is quite recent, however historical and cultural heritage constructions are also made of RC. To preserve the historic value of such structures could require minimally invasive measures aimed at long-term safeguarding, if they are well designed; but it is important to evaluate material characteristics. For this purpose it is necessary to use non destructive tests (NDT) to evaluate the level of degradation reached by the materials composing the structures. Main electrochemical NDT are measurement of corrosion rate and open circuit potential. The use of such techniques requires the removal of small portions of concrete cover only. They, indirectly, allow the value of corrosion penetration to be evaluated. Previous studies provided analytical models to assess crack initiation and propagation according to different values of concrete strength, concrete cover, bar diameter and type of aggregates. Such models better perform for new buildings because historic structures are usually expected to present a visible crack pattern. This paper presents another tool in the box of practitioners to assess and evaluate the vulnerability of existing structures. In particular proposed model provides bar reduction in terms of diameter or cross sectional area, depending on actual crack opening. Outputs of the paper are design charts providing direct correlation between crack width and steel reinforcement loss depending on few geometrical dimensions of RC elements.

PL

Beton zbrojony (RC) jest powszechnie stosowanym materiał od około 100 lat. Głównymi przyczynami degradacji jest nasycenie dwutlenkiem węgla, chlorki i atak siarczki. Pomimo, że dyfuzja konstrukcji żelbetowych jest stosunkowo nowa, konstrukcje dziedzictwa historycznego i kulturowego są także są wykonane z betonu zbrojonego. Aby zachować zabytkową wartość takich struktur wymagana jest długoterminowe zabezpieczenie. W tym celu konieczne jest użycie testów destrukcyjnych (NDT) do oceny stopnia degradacji. Bardzo ważny jest pomiar szybkości korozji i potencjał otwartego obwodu. Stosowanie takich technik wymaga usunięcia jedynie małej części otuliny.

8

The effect of fiber content on the ultrasonic wave velocity in glass/polyester composites

Wróbel G., Pawlak S.

Journal of Achievements in Materials and Manufacturing Engineering

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2007

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Vol. 20, nr 1-2

295-298

EN

Purpose: The primary purpose of the present study was to find relationship between ultrasonic wave velocity and the fiber content in glass/polyester composites. In addition, further tests were conducted to determine how other factors can affect the ultrasonic velocity. Design/methodology/approach: Experimental data have been obtained using ultrasonic wave velocity measurements and standard destructive analysis. For ultrasonic non-destructive testing, through-transmission technique was used. Findings: Experimental results have shown that the longitudinal wave velocity increases almost linearly with an increase of the fiber content in investigated specimens. Research limitations/implications: The propagation velocity of the ultrasonic waves can be affected, apart from fiber content, by interfacial stresses and changes of elastic modulus in polymer matrix during long-lasting conditioning. These factors overlap and which of the two can affect the ultrasonic wave to a higher degree is yet to established. Further work is needed in this area. Practical implications: Ultrasonic wave velocity measurement seems to be an effective method of fiber content evaluation, but for any different composites, distinct relationships should be determined. Originality/value: The results obtained would be of considerable importance in industrial applications to achieve a first estimate of fiber content variations in composite materials.

9

Finger curvature movement recognition interface technique using SEMG signals

Itoh Y., Uematsu H., Nogata F., Nemoto T., Inamori A., Koide K., Matsuura H.

Journal of Achievements in Materials and Manufacturing Engineering

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2007

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Vol. 23, nr 2

43-46

EN

Purpose: Until recently, keyboard has been used as the primary input method for machinery operation system. But in recent years, numerous methods related to direct input interface have been developed. One of them is to measure the surface electric potential that generates on the skin surface during muscle contraction. Based of this fact, hand finger operation can also be recognized with the help of the surface muscle electric potential. The purpose of this study is to identify the hand finger operation using surface electromyogram (SEMG) during crookedness state of the finger. Design/methodology/approach: Two electrodes (Ag-AgCl electrode) were sticked randomly on the forearm muscles and the intensity of EMG signals at different muscles were measured for each crooked finger. Then depending on the intensity of the obtained electric potentials, a position was located and considered to have participated most actively during the crookedness state of that finger. Thus five locations on the forearm muscles were identified for five different fingers. Moreover, four different types of crookedness states were considered for each finger. Findings: In this experimental study, the electric current that generates on the skin during muscle activity was measured for different hand finger operations. As a result, it is found that there is a specified position related the maximum intensity of EMG signals for each finger. Practical implications: This paper cleared that the amount of crookedness of each finger can also be recognized with the help of surface EMG. It could be used as a machine interface technology in the field of welfare equipments, robot hand operation, virtual reality, etc. Originality/value: The objective of this research project was to develop the method of recognizing the hand finger operation and their crookedness states from surface electromyogram (SEMG).