Wyniki wyszukiwania - BazTech

1

Thermal Impedance Measurement of Thick-Film Resistor in High-Frequency Range Using Single-Detector IR System

Strąkowska Maria, Więcek Bogusław, De Mey Gilbert

Pomiary Automatyka Robotyka

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2024

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R. 28, nr 1

81--87

EN

This paper presents an innovative and simple method of high-frequency thermal impedance measurement using infrared (IR) technique. The method is based on the Fourier transformation of the input power signal and the thermal response of the object after supplying the heat source with square-wave current of different frequencies. The experiment was carried out using a single-detector, low-cost infrared system equipped with a photovoltaic detector module to measure the thermal impedance of an SMD thick-film resistor. Both the simulation using a compact thermal model and the measurement results are discussed.

PL

Artykuł przedstawia nową, prostą metodę pomiaru impedancji termicznej w zakresie dużych częstotliwości przy wykorzystaniu technik podczerwieni. W tym celu zastosowano transformację Fouriera sygnału wejściowego oraz odpowiedzi termicznej badanego obiektu po pobudzeniu go źródłem ciepła w postaci prądu o kształcie prostokątnym i o różnej częstotliwości. Eksperyment został przeprowadzony przy użyciu taniego systemu termowizyjnego z pojedynczym fotowoltaicznym detektorem podczerwieni w celu pomiaru impedancji termicznej grubowarstwowego rezystora SMD. Badana próbka pobudzana była sygnałem prostokątnym o różnych częstotliwościach z zakresu 2-100 Hz, a system IR rejestrował zmianę wartości jego temperatury. W celu potwierdzenia poprawności uzyskanych wyników badań opracowano model kompaktowy RthCth struktury rezystora oraz podłączonych do niego wyprowadzeń. Przeprowadzone symulacje potwierdziły poprawność zarówno metody pomiaru jak i opracowanego modelu termicznego. Kształt wykresów Nyquista impedancji termicznej dla modelu jak i pomiaru jest zbliżony. W zakresie dużych częstotliwości oba wykresy zbliżają się do linii o nachyleniu -45° przekraczając tę linię w dwóch punktach. Zaproponowana metoda pomiaru impedancji termicznej jest szybka, niezawodna, nieinwazyjna i bezkontaktowa. Może być wykorzystana również do zastosowań biomedycznych np. do diagnostyki chorób skóry. Metoda ta upraszcza identyfikację termiczną obiektów w stanie dynamicznym i może być alternatywą dla stosowania do tego celu drogich systemów termowizyjnych z detektorami chłodzonymi.

2

Potential of Indirect Regenerative Evaporative Cooling System (M-Cycle) for Electronic Applications

Olbrycht Robert, Kałuża Marcin, Felczak Mariusz, Levchenko Dmytro, Więcek Bogusław

Pomiary Automatyka Robotyka

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2023

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R. 27, nr 3

19--25

EN

The article presents a simple prototype system based on the concept of indirect regenerative evaporative cooling (IREC) thermodynamic cycle for electronics applications. The key problem of selecting porous capillary material is discussed and preliminary experimental results are presented using IR thermography. The presented research is an initial step towards the development of a laboratory-validated, fully operational IREC system for high-power electronics.

PL

W artykule przedstawiono prototypowy układ chłodzenia oparty na koncepcji cyklu termodynamicznego pośredniego regeneracyjnego chłodzenia wyparnego (IREC) do zastosowań w elektronice. Omówiono kluczowy problem doboru porowatego materiału kapilarnego i przedstawiono wstępne wyniki eksperymentów z wykorzystaniem termografii w podczerwieni. Przedstawione badania stanowią wstępny krok w kierunku opracowania zweryfikowanego laboratoryjnie, w pełni funkcjonalnego systemu IREC do odprowadzania ciepła w systemach elektronicznych dużej mocy.

3

Deformation behaviour of high-manganese steel with addition of niobium under quasi-static tensile loading

Jabłońska Magdalena Barbara, Jasiak Katarzyna, Kowalczyk Karolina, Bednarczyk Iwona, Skwarski Mateusz, Tkocz Marek, Gronostajski Zbigniew

Materials Science Poland

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2022

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Vol. 40, No. 3

1--11

EN

In this paper, the heat generated during deformation under the static testing of high-manganese TWIP steel with addition of niobium was determined. The research combined the interaction of heat generated during deformation, mechanical properties, hardness and microstructure. Temperature and strain were measured simultaneously using infrared (IR) thermography and digital image correlation (DIC) method. The average temperature measured at the necked region equals 42°C at the strain rate of 0.001 s−1 and exceeds 100°C at 0.5 s−1. Therefore at large strains, a reduction in stress was observed. The course of the hardness change coincides very well with the strain changes, however, at the strain rate of 0.5 s−1 near to the necking area the hardness equals to 360 HV2, whereas at the lower strain rates it equals to 370 HV2. These changes are connected mainly with increase in temperature to >100°C

4

The use of thermography in preliminary research on temperature of burnishing

Molenda Justyna, Charchalis Adam

Journal of KONBiN

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2022

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Vol, 52, iss. 2

143--162

EN

The paper presents the methodology and results of experimental works concerning temperature of burnishing process. The research was carried out during disk burnishing of external cylindrical surfaces on a universal lathe CDS 6250 BX-1000 with severe parameters. As workpiece material steel S235JR has been selected. For temperature measurements infrared thermography method was chosen. This technique has a lot of advantages, the main is that it is non-contact technique and therefore there is no disturbance of the temperature field. In presented research infrared camera E95 produced by FLIR® Systems Inc. was used. Test results indicates the slight influence of process parameters on burnishing temperature.

PL

W pracy przedstawiono metodykę i wyniki prac eksperymentalnych związanych z wyznaczeniem temperatury nagniatania. Badania prowadzono w trakcie nagniatania krążkowego zewnętrznych powierzchni walcowych na tokarce uniwersalnej CDS 6250 BX-1000 przy różnych parametrach obróbki. Jako materiał obrabiany przyjęto stal S235JR. Do pomiarów temperatury wybrano metodę termograficzną, ze względu na szereg jej zalet na tle innych metod. Główną zaletą jest możliwość zdalnego, bezkontaktowego pomiaru, dzięki czemu rozkład temperatury na powierzchni jest niezakłócony. W przedstawionych badaniach do pomiaru temperatury stosowano kamerę E95 firmy FLIR® Systems, Inc. Wyniki badań wskazują, że wpływ parametrów nagniatania na temperaturę w strefie obróbki jest niewielki.

5

Non-Destructive Evaluation of Composite Helmets Using IR Thermography and Ultrasonic Excitation

Świderski Waldemar, Pracht Monika

Pomiary Automatyka Robotyka

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2021

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R. 25, nr 4

89--92

EN

The paper presents selected results of non-destructive testing of composite helmets with deliberately introduced defects. Ultrasound pulsed infrared thermography was used for the tests. In order to determine the initial possibilities of this method, artificial defects made of Teflon featuring different area sizes and designed to simulate delamination were placed between layers of the aramid composite from which the helmet was made. The obtained results confirmed the effectiveness of the NDT method used in these tests.

PL

W pracy przedstawiono wybrane wyniki badań nieniszczących hełmów kompozytowych z celowo wprowadzonymi defektami. Do badań wykorzystano impulsową termografię w podczerwieni z ultradźwiękowym źródłem wzbudzenia cieplnego. W celu określenia wstępnych możliwości tej metody, pomiędzy warstwami kompozytu aramidowego, z którego wykonano hełm, umieszczono na różnych głębokościach pod powierzchnią sztuczne defekty wykonane z teflonu o różnej wielkości powierzchni. Te sztuczne defekty symulowały rozwarstwienia. Uzyskane wyniki potwierdziły skuteczność użytej metody NDT w tych badaniach.

6

Experimental Testing of Aramid Composite Applied in Ballistic Armour using Ultrasonic IR Thermography

Pracht Monika, Świderski Waldemar

Problemy Mechatroniki : uzbrojenie, lotnictwo, inżynieria bezpieczeństwa

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2019

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Vol. 10, Nr 2 (36)

79--88

EN

Reference samples, in which artificial discontinuities (defects) are fabricated, are used to verify non-destructive testing procedures. Artificial discontinuities are known defects of reference samples and enable verification the possibilities of using the chosen NDT method for the identification of location and depth of discontinuities. In thermographic methods the tests of reference samples also allow (helps) to determine the required thermal stimulation source parameters of the tested sample. This paper presents the results of experimental testing of defects detection in a multi-layer aramid composite used in light ballistic armour using ultrasonic infrared thermography. Samples of the aramid composite included artificial defects and were tested using different ultrasonic frequencies. The tests of the same samples were carried out with optical thermography and X-ray method and their results were compared to those determined with ultrasonic IR thermography.

PL

Do sprawdzenia procedur badań nieniszczących są stosowane próbki wzorcowe, w których wprowadzono sztuczne nieciągłości (defekty). Nieciągłości sztuczne wprowadzone w próbkach wzorcowych umożliwiają zweryfikowanie przede wszystkim możliwości zastosowania wybranej metody do określenia położenia i głębokości nieciągłości. W metodach termograficznych badania próbek wzorcowych pozwalają również określić potrzebne parametry źródła stymulacji cieplnej badanej próbki. W artykule przedstawiono wyniki badań eksperymentalnych wykrywania defektów w wielowarstwowym kompozycie aramidowym stosowanym w konstrukcji lekkich osłon balistycznych metodą ultradźwiękowej termografii w podczerwieni. Badania próbek kompozytu aramidowego z celowo wprowadzonymi defektami, przeprowadzono przy zastosowaniu różnych częstotliwości ultradźwięków. W celu porównania uzyskanych wyników badań, wykonano badania metodami optycznej termografii i rentgenografii.

7

Reduction of Fringing-Effect in Inductors by Quasi-Distributed-Gap Method

Kasikowski Rafał

Measurement Automation Monitoring

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2019

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Vol. 65, No. 2

48--51

EN

The fringing-field phenomenon can have a significant impact on the key performance parameters of magnetic components with an air gap. The fringing magnetic flux at the air gap has an effect on a component’s inductance, power loss and temperature distribution in copper windings. The induced excess eddy currents in the windings due to the fringing effect cause localized heating and reduce the overall efficiency of power conversion. This effect can be analysed by infra-red thermography to demonstrate the potential hazards of designing magnetic components with an air gap. Design engineers are frequently forced to design around the problem by employing a number of available techniques. The quasi-distributed-gap technique combats the issue at the origin as it essentially constrains the fringing magnetic flux at the downsized air gaps to their immediate vicinity. The selection of the length of the individual air gaps as well as their placement is not straightforward, as the phenomenon is a function of the air gap length and geometry. The resulting inductance of the component has to be the same or at least comparable to the original value in order to maintain the operating conditions of the application which the component is part of. This paper examines the effects of splitting a discrete air gap on the electromagnetic and thermal properties of inductors and presents a method to aid the design of quasi-distributed-gap inductors based on finite-element simulations as well as measurements. An analytic expression, which closely approximates the required length of quasi-distributed gaps, is developed.

8

Comparison of image analysis methods on the example of ultrasonic thermography of an aramid composite

Świderski Waldemar

Journal of KONES

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2019

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Vol. 26, No. 2

145--150

EN

Infrared thermography using ultrasound thermal excitation of the tested material is one of the most effective methods in non-destructive testing of a multi-layer aramid composite. This type of material is very popular in the construction of light ballistic armours. Typical defects are delamination between layers of aramid fabric joined by resin. They are usually filled with air. Delamination located deep under the surface of the test generates very weak temperature signals. They are often at the level of noise. To reduce the impact of noise on the detection of a defect, special methods of image analysis (thermograms) are used. Such methods include principal component analysis and wavelet analysis. Principal Component Analysis is a relatively new procedure of statistical data treatment, which is becoming increasingly popular in non-destructive testing. Mathematically, it is often regarded as implementation of the so-called singular values decomposition technique, which allows extracting of spatial information from a matrix of source data. The wavelet analysis is an integral transform, which represents the convolution of an analysed process with a special mother function called wavelet. Wavelets are characterized by two parameters: scale and shift. The paper presents a comparison of the efficacy of these methods in the detection of defects in the multilayer composite reinforced aramid fibre.

9

Thermal modeling and RMS current measurement in electrical power lines using IR thermography

Torzyk B., Więcek B.

Measurement Automation Monitoring

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2018

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Vol. 64, No. 3

53--56

EN

Thermal modeling in frequency domain and experiments using IR thermography are performed to evaluate RMS current in electrical power lines. The model implements interface thermal resistance between the metal core and insulation layer. This allowed matching the results of simulations and measurements with acceptable accuracy. The proposed method requires the use of known values of heat transfer coefficient and thermal parameters of the cable and its insulation. In consequence the proposed method requires calibration.

10

Influence of thermal signal characteristics on defect detection in GFRP by active optical thermography

Świderski W.

Journal of KONES

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2018

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Vol. 25, No. 1

379--383

EN

Advances in technological development, since the 1990s, has been associated with the development of two basic domains of knowledge: information technology and material engineering. The development of material engineering is directly related to composite materials. One group of composite materials are fibre-reinforced composites. Due to their unique properties, they are used in various fields of engineering sectors. Composites reinforced with glass fibre (GFRP) are the second most commonly used composite after carbon fibre reinforced composites (CFRP). GFRP in many cases can replace traditional structural materials, which are usually made from metal. Of course, this material is exposed to damage both in production and operation phases. One method of non-destructive testing that effectively identifies defects in GFRP is active optical thermography. In this method, for thermal stimulation of the tested material, various types of heat sources are used for example: heating lamps, lasers etc. This article analyses the influence of the characteristics of the thermal optical sources on detection of typical defects in GFRP.

11

The use of IR thermography for testing operation parameters of plate steel and accumulative wood stoves

Żołądek M., Sornek K., Boroń A., Nabożna S., Filipowicz M.

Measurement Automation Monitoring

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2017

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Vol. 63, No. 4

162--165

EN

This paper shows the possibility of the use of IR thermography for testing the operational parameters of wood stoves. The study showed differences in the operation parameters of the plate steel wood stove, plate steel wood stove with accumulation and accumulative wood stove. There were compared temperature distribution on the external surfaces of tested units and the amount of energy transferred to heated rooms. Moreover, there were also tested two types of units dedicated to heat recovery from flue gas: flue gas to air steel heat exchanger and accumulative ceramic heat exchanger. The use of IR thermography allowed to simplify measurements and gave approximate results in comparison to more detailed tests.

12

Impact of the fringing effect on temperature distribution in windings and physical properties of toroidal ferrite inductors with a dual air gap

Kasikowski R.

Measurement Automation Monitoring

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2017

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Vol. 63, No. 4

135--138

EN

This paper examines the impact of the fringing field at an air gap on the temperature distribution, power loss and other properties of toroidal ferrite inductors with a dual air gap. An air gap constitutes a discontinuity in a magnetic path of an inductor, representing significantly greater reluctance to magnetic flux than that of a ferrite core. The magnetic flux does not cross the air gap in straight lines, but fringes out into the surrounding medium causing electromagnetic interactions with the copper winding enclosing the air gap. This phenomenon is a function of the air gap and the windings geometry as well as the operating frequency. The net effect of the fringing flux is to shorten the gap and to decrease the effective reluctance of the magnetic path. Consequently, coils wound on magnetic cores with a relatively large single air gap, thus with an exacerbated fringing effect, exhibit higher inductance than those with multiple, quasi-distributed or distributed air gaps of the same effective length as the discrete one. The presented research investigates the effects of splitting a discrete air gap on the electromagnetic and thermal properties of toroidal ferrite inductors.

13

Convection and radiation cooling of overhead power lines - laboratory verification using thermography

Chatzipanagiotou P., Felczak M., De Mey G., Chatziathanasiou V., Więcek B.

Measurement Automation Monitoring

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2017

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Vol. 63, No. 3

107--110

EN

The thermal behavior of overhead power lines depends upon physical parameters, such as surface emissivity and line dimensions, as well as weather conditions. In this paper, the results of the convection and radiation cooling of a conductor that simulate a power line are presented. Laboratory experiments were conducted and the results were compared with the data obtained using empirical formulae from the literature. Both the laminar and the turbulent airflow were investigated.

14

A new software tool for transient thermal analysis based on fast IR camera temperature measurement

Chatzipanagiotou P., Strąkowska M., De Mey G., Chatziathanasiou V., Więcek B., Kopeć M.

Measurement Automation Monitoring

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2017

|

Vol. 63, No. 2

48--51

EN

A new software tool for transient thermal analysis based on thermographic measurement of temperature is presented. In the proposed approach, temperature change after applying or removing power can be measured by a thermal camera or any contact temperature sensor. The software calculates thermal impedance in frequency domain and represents it in the form of the Nyquist plot. In addition, thermal time constant spectrum and cumulative structure function are evaluated. The software was developed in Matlab environment using in-built procedures for transfer function estimation. For the validation of the proposed tool, the results are compared with ones obtained using commercially available software.

15

Non-destructive evaluation of sandwich plates by an ultrasonic IR thermographic method

Świderski W., Hłosta P., Chuda-Kowalska M.

Measurement Automation Monitoring

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2016

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Vol. 62, No. 12

406--410

EN

The paper presents the possibility of using an ultrasonic IR thermographic method to detect internal defects in composite types of sandwich panels with metal sheets. Experimental results indicate that this method may in many cases be effective in detecting defects that weaken the structure of sandwich panels. The results also show the limitations of using this method to sandwich panels and the materials used in them.

16

Detection of very thin defects in CFRP by the lock-in thermography method

Świderski W.

Journal of KONES

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2016

|

Vol. 23, No. 1

385--390

EN

Quick development of constructional composite materials application is caused by their excellent mechanical and strength-related properties, combined with a low specific weight. One of the basic groups of reinforcement materials in composites are carbon fibres discovered back in 19th century. The main reason of defects in structures of composite materials is the variability of working charges in constructions during the process of using. Existed defects are complicated because of the effects like loss of continuity of reinfused fibres, binder cracks and loss of fibres adhesiveness to binder. Diagnostic methods, which are effective with relation to metals became little effective when used in detection of defects in composite materials. This caused greater interest of diagnostic techniques with using infrared thermography. Lock-in thermography is one of NDT methods providing phase images of thermal waves in a sample leading to receiving a distribution of internal defects and allowing for thermal properties evaluation. We used lock-in thermography in connection with modulated thermal source synchronized with the IR image acquisition camera. It was prepared sample of multilayer structure carbon composite with deliberately introduced defects for comparative purposes. Very thin defects of different sizes and shapes made of Teflon or copper having a thickness of 0.1 mm were searches. The results are reported in the paper.

17

The use of IR thermography to show the mold and part temperature evolution in injection molding

Bula K., Różański L., Marciniak-Podsadna L., Wróbel D.

Archives of Mechanical Technology and Materials

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2016

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Vol. 36

40--43

EN

This study concerns the application of infrared camera for injection molding analysis by measuring temperatures of both injection molded parts and injection mold cavities in a function of injection cycles. The mold with two cavities, differing in thickness (1 and 3 mm), and a cold direct runner was used. Isotactic polypropylene homopolymer was utilized to produce parts. Mold temperature was set at 22OC and controlled by a water chiller. Five measuring points were determined: SP1, SP2 (placed in the 3 mm cavity), SP3, SP4 (located in the 1 mm cavity) and SP5 around an injection molding gate. Our investigations showed that the highest temperature is localized around SP2 point and the lowest at SP4. Also, it was proved that even after 62 injection molding cycles, temperatures of cavities were not stable, revealing their further increase with each cycle.

18

Thermographic method based accelerated fatigue limit calculation for steel X5CRNI18-10 subjected to rotating bending

Lipski A.

Polish Maritime Research

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2015

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nr 4

64--69

EN

The article presents an accelerated method for fatigue limit calculation which makes use of constant temperature increase rate observed in the middle time interval of specimen fatigue loading. The examination was performed on specimens prepared from drawn rods made of corrosion resistant austenitic steel X5CrNi18-10 (1.4301) subjected to rotating bending. For comparison purposes, the fatigue limit was also calculated with the aid of the Staircase method, using 30 specimens and assuming the base number of cycles equal to 10・106. Three specimens were used for accelerated examination during which their temperature was measured with the aid of the thermographic camera CEDIP Silver 420M (FLIR SC 5200). The applied loads were gradually increased until specimen damage took place. Based on the analysis of temperature changes during specimen loading, the average rate of temperature increase at successive loading stages was assessed. The obtained results were then approximated using the 2-nd order curve and its minimal value was assumed as corresponding to the fatigue limit. The performed statistic test has revealed that the fatigue limit calculated in the above way does not differ substantially from that determined using the Staircase method.

19

Ultrasonic IR thermographic inspection of graphite epoxy composite: a comparative study of piezoelectric and magnetostrictive stimulation

Swiderski W., Vavilov V.

Opto-Electronics Review

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2015

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Vol. 23, No. 1

33-36

EN

In this paper the experimental results of piezoelectric and magnetostrictive ultrasonic stimulation are comparatively analyzed in the evaluation of impact damage in a graphite epoxy composite sample chosen for a round robin test. By comparing theoretical and experimental results, it is shown that the equivalent power of internal friction can reach some hundreds mill watt per a single crack.

20

Various applications of complex thermal impedance for transient and AC heat transfer analysis

Więcek B., De Mey G., Strąkowska M., Chatziathanasiou V., Gmyrek Z., Strzelecki M., Chatzipanagiotou P.

Measurement Automation Monitoring

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2015

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Vol. 61, No. 6

210--214

EN

This paper presents the concept and three practical examples of using complex thermal impedance for characterisation different thermal objects. The first problem describes estimation time shift between power and temperature in electric distribution systems with non-sinusoidal currents. The second example discussed here, shows the estimation of power losses distribution in the magnetic punched ferromagnetic strips. The third application presents the inverse thermal modelling of 3-layer biomedical objects (tissues) to estimate the thermal parameters. More details of the presented problems are in the appropriate papers of the authors referenced here.