Wyniki wyszukiwania - Biblioteka Nauki

1

May thermal imaging be useful in early diagnosis of lower extremities chronic venous disease?

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Kajewska J. , Stanek A. , Sieroń K. , Cholewka A.

Polish Journal of Medical Physics and Engineering

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2023

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tom Vol. 29, Iss. 1

73--84

EN

Introduction: World statistics confirmed that about 40-50% of men and 50-55% of women suffer from chronic venous disease. Currently, the Duplex ultrasound is the leading diagnostic method for chronic venous disease (CVD), but it has some limitations. Therefore, it is important to find a new diagnostic technique that will provide additional parameters, describing not only structural but also early metabolic and functional changes. Materials and Methods: This study aimed to demonstrate the usefulness of the thermal imaging technique in the diagnosis of chronic venous disease. Results were obtained for two groups: 61 patients suffering from the primary chronic venous disease (CVD group) and 30 healthy people (control group). The obtained results compared the thermal imaging parameters to data obtained from the ultrasound examination. Parameters such as the reflux duration and extent of the CEAP classification were correlated with the mean temperature of the limb, the mean temperature of the lesion (determined using two methods), and the thermal range. Based on data obtained during the study, correlation coefficients were calculated for individual parameters. Results: The results obtained show that the mean limb temperature, and especially the mean temperature of a proposed isothermal area, is significantly correlated with the range of reflux. The conducted tests showed the correlation between some thermal and ultrasonic parameters determined by Spearman's coefficient is 0.4 (p < 0.05). Conclusions: Thus, parameters such as the isothermal area and the thermal range may be used as a preliminary quantitative diagnosis, similarly to those derived from the Duplex ultrasound.

2

Configuration of systems for testing thermal imagers

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Chrzanowski K. , Li X.

Optica Applicata

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2010

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tom Vol. 40, nr 3

727--735

EN

Systems for testing thermal imagers offered commercially are built from the same modules: an off-axis reflective collimator, a motorized rotary wheel, a set of IR targets, a black body, a black body/wheel controller, a PC and some software. The classical solution is that all these components are located horizontally on an optical table. However, it is also possible to use a vertical configuration of the test system when the rotary wheel is put on the collimator and the black body is put on the rotary wheel. It was shown in this paper that when the vertical configuration is used, then better temporal stability and spatial uniformity of the thermal images projected by the test system can be achieved.

3

Temperature Distribution Analysis on the Surface of the Radiator: Infrared Camera and Thermocouples Results Comparison

100%

Kotrys-Działak D. , Stokowiec K.

Rocznik Ochrona Środowiska

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2023

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tom Tom 25

37--44

EN

The experiments conducted in a didactic laboratory of the Kielce University of Technology involved temperature distribution measurements on the outer surface of a steel radiator using a thermal imaging camera and thermocouples to compare both investigation methods. The research included registering the parameters for a specific period for each of the four different medium flows. Graphs present the results with the division of the radiator into eight thermal fields. The results present the differences in temperatures between 1.78°C to 3.65°C. The non-contact method with an infrared camera seems more accurate since it is precise for surface temperature measurement.

4

Linear HgCdTe IR FPA 288 × 4 with bidirectional scanning

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Vasilyev V. V. , Predein A. V. , Varavin V. S. , Mikhailov N. N. , Dvoretsky S. A. , Gumenjuk-Sichevska J. V. , Golenkov A. G. , Reva V. P. , Sabinina I. V. , Sidirov Y. V. , Susliakov A. O. , Sizov F. F. , Aseev A. L.

Opto-Electronics Review

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2010

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tom Vol. 18, No. 3

332-337

EN

The long wavelength (8-12 μm) IR FPA 288×4 based on a hybrid assembly of n+-p diode photosensitive arrays (PA) of HgCdTe (MCT) MBE-grown structures and time delay integration (TDI) readout integrated circuits (ROIC) with bidirectional scanning have been developed, fabricated, and investigated. The p-type MCT structures were obtained by thermal annealing of as-grown n-type material in inert atmosphere. The MCT photosensitive layer with the composition 0.20-0.23 of mole fraction of CdTe was surrounded by the wide gap layers to decrease the recombination rate and surface leakage current. The diode arrays were fabricated by planar implantation of boron ions into p-MCT. The typical dark currents were about 4-7 nA at the reverse bias voltage of 150 mV. The differential resistance R was up to R₀ = 1.6×10⁷ Ω zero bias voltage, which corresponded to R₀A ∼70 Ω •cm² and to the maximal value Rmax = 2.1 × 10⁸ Ω. The bidirectional TDI deselecting ROIC was developed and fabricated by 1.0-μm CMOS technology with two metallic and two polysilicon layers. The IR FPAs were free of defect channels and have the average values of responsivity Sλ = 2.27×10⁸ V/W, the detectivity Dλ * = 2.13 × 10¹¹ cm × Hz½ × W⁻¹, and the noise equivalent temperature difference NETD = 9 mK.

5

The Use of Thermal Imaging in the Evaluation of the Symmetry of Muscle Activity in Various Types of Exercises (Symmetrical and Asymmetrical)

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Chudecka M. , Lubkowska A. , Leźnicka K. , Krupecki K.

Journal of Human Kinetics

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2015

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tom 49

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nr 1

141-147

EN

In order to achieve higher efficiency of training and thus better athletic performance, new research and diagnostic methods are constantly being developed, particularly those that are non-invasive. One such a method is thermography, suitable for quantitative and therefore objective evaluation of variables, such as changes in the temperature of the skin covering working muscles. The aim of this study was to use a thermal imaging infrared camera to evaluate temperature changes of symmetric body surfaces over symmetrically working muscles of male scullers after exercising on a two-oared rowing ergometer and compare these to asymmetrically working muscles of handball players after an endurance training session containing elements of an actual game. In the scullers, the mean temperature of body surfaces was always lower post than pre exercise, with no significant differences in an average temperature drop between the opposite sides, indicating that the work of the muscles involved in the physical exertion on the rowing ergometer was symmetrical. In contrast, in the handball players, skin temperatures in symmetric areas over the asymmetrically working muscles showed statistically significant differences between sides, which was associated with the functional asymmetry of training. This study indicates that thermal imaging may be useful for coaches in the evaluation of technical preparations in sports in which equal involvement of symmetric muscles is a condition of success, e.g. in scullers.

6

Laboratory methods for testing the performance of pyrotechnic delay elements

100%

Warchol R. , Nita M.

Scientific Journal of the Military University of Land Forces

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2018

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tom Vol. 50, No. 4(190)

101--115

EN

Pyrotechnic delay elements owing to their simple structure and reliability are very often used as part of the design of ammunition. Their basic task consists in generating a specified delay between the respective actions of two elements/systems, required to ensure the safe and reliable work of ammunition. The paper presents laboratory methods employed for testing the performance of pyrotechnic delay elements (PDEs) used in means of combat. The introductory part describes pyrotechnical delay elements and the task fulfilled by them in ammunition. The next part discusses performance parameters of pyrotechnic delay elements, decisive for their proper operation, and factors influencing such operation. In its main part the article presents the standard defining the laboratory methods to be employed for testing pyrotechnic delay elements. According to the above-mentioned standard, the laboratory methods of testing pyrotechnic delay elements can be divided into tests in the open and closed systems. Further, the paper discusses both types of test systems. Taking account of a wide thematic scope of the discussed issue, this article focuses mainly on presenting new methods of testing pyrotechnic delay elements, which have not been mentioned in the standard. Provided examples of tests of pyrotechnic delay elements have been taken from the Polish and foreign literature. Two methods of testing pyrotechnic delay elements are worth paying special attention, one making use of a thermal imaging camera, and the other relying on Roentgen radiation.

7

Przydatność termowizji do diagnostyki technicznej urządzeń energomechanicznych w zakładach górniczych

100%

Malicki W. , Miedziński B.

Mechanizacja i Automatyzacja Górnictwa

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2009

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tom R. 47, nr 7

34-38

PL

W artykule omówiono zarówno przydatność jak i podano możliwości wykorzystania termowizji do diagnostyki technicznej urządzeń energomechanicznych w zakładach górniczych. Wykazano, że prawidłowo opracowana analiza wykonanych zdjęć termowizyjnych daje szereg cennych informacji o stanie technicznym pracującego urządzenia. Pozwoli to na podjęcie, w szeregu przypadkach i w odpowiednim czasie, istotnych decyzji zapobiegających potencjalnym awariom.

EN

There have been discussed both a usefulness and a usability of thermal imaging for a technical diagnostics of energy-mechanical devices in mines. It has been proven that a correctly prepared analysis of thermal images gives a number of valuable information on a technical state of operation of a device. This may allow the crucial decisions to be taken in many cases and in a proper time which would prevent possible failures.

8

Fusion of Depth and Thermal Imaging for People Detection

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Gutfeter W. , Pacut A.

Journal of Telecommunications and Information Technology

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2021

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tom nr 4

53--60

EN

The methodology presented in this paper covers the topic of automatic detection of humans based on two types of images that do not rely on the visible light spectrum, namely on thermal and depth images. Various scenarios are considered with the use of deep neural networks being extensions of Faster R-CNN models. Apart from detecting people, independently, with the use of depth and thermal images, we proposed two data fusion methods. The first approach is the early fusion method with a 2-channel compound input. As it turned out, its performance surpassed that of all other methods tested. However, this approach requires that the model be trained on a dataset containing both types of spatially and temporally synchronized imaging sources. If such a training environment cannot be setup or if the specified dataset is not sufficiently large, we recommend the late fusion scenario, i.e. the other approach explored in this paper. Late fusion models can be trained with single-source data. We introduce the dual-NMS method for fusing the depth and thermal imaging approaches, as its results are better than those achieved by the common NMS.

9

Termowizyjna ocena zmian temperatury w okolicy grzbietowej pod wpływem masażu relaksacyjnego gorącymi kamieniami

100%

Witoś M. , Podbielska H. , Demczuk-Włodarczyk E.

Acta Bio-Optica et Informatica Medica. Inżynieria Biomedyczna

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2009

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tom Vol. 15, nr 3

239-243

PL

Badaniami objęto grupę piętnastu kobiet, prowadzących siedzący tryb pracy, w średnim wieku 31 lat (odchylenie standardowe 10, 24). Wykonano, w odstępie tygodnia, serię trzech masaży relaksacyjnych gorącymi kamieniami okolicy grzbietu. Przed i po każdym zabiegu rejestrowano rozkład temperatury kamerą termowizyjną (ThermoVision A20 M, FLIR System). Na podstawie badań termowizyjnych i po analizie przeprowadzonej ankiety stwierdzono, że temperatura powierzchni pleców osób badanych wzrastała po każdym masażu. Co za tym idzie, obniżyło się napięcie mięśni grzbietu. Po serii masażu dolegliwości bólowe ze strony kręgosłupa i obręczy barkowej zmniejszyły się. Również ogólny stan psychiczny osób badanych uległ poprawie.

EN

Fifteen female volunteers, working in sitting position, with average age of 31 (stand. dev. 10,24) were subjected to the hot stones therapy. The series of 3 massages were performed every other week. The temperature distribution of the upper back before and after each hot stones massage was evaluated by means of thermal camera (ThermoVision A20 M, FLIR System). The special questionnaire was elaborated and analyzed, as well. After the analysis it was stated that the hot stones massage caused the decrease of the pain in the upper back, as well as resulted in the lowering of the muscles tension. Thus, the psychical state of the subjects improved, as well

10

USE OF THERMAL IMAGING IN THE EVALUATION OF BODY SURFACE TEMPERATURE IN VARIOUS PHYSIOLOGICA L STATES IN PATIENTS WITH DIFFERENT BODY COMPOSITIONS AND VARYING LEVELS OF PHYSICAL ACTIVITY

100%

Chudecka M.

Central European Journal of Sport Sciences and Medicine

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2013

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tom 2

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nr 2

15-20

EN

This is a review of thermal imaging methods used for the measurement of body surface temperatures, including the most important medical applications, papers on thermal maps of people with various body compositions, and the applicability of thermal imaging in sport training.

11

Age dependence of thermal imaging analysis of body surface temperature in women after cryostimulation

100%

Dębiec-Bąk A. , Gruszka K. , Sobiech K. A. , Skrzek A.

Human Movement

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2013

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tom 14

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nr 4

299-304

EN

Purpose. The aim of the study was to analyse changes in body surface temperature after a cryostimulation session in women of two different age groups. Methods. The study included 21 female university students aged 21 ± 1.8 years and 15 middle-aged women aged 57.8 ± 3.6 years. All participants were subjected to the effects of extreme low temperature in a cryogenic chamber at -120˚C for 3 min. Body surface temperature measures were taken before and immediately after treatment by a thermal imaging camera. Qualitative and quantitative analysis of the captured thermographic images was performed for 12 anterior and posterior body areas in the standing position. Results. Differences in body surface temperature were found between both age groups prior to the cryostimulation treatment. Temperatures ranged from 29.55° C to 33.49° C in the younger group and 30.45° C and 32.70° C in the older group for the same body areas. Lower temperatures were observed in the older subject group for all analysed areas. After cryostimulation, greater body cooling was observed in the younger group particularly in the lower limbs. The greatest temperature reduction in both groups was observed in the lower limbs, dropping a maximum of 6.31° C, whereas the lowest variation in temperature was observed in the shoulder area by approximately 2° C. Conclusions. The results of the study showed varied distribution of body surface temperature in both age groups. Lower temperatures of the trunk and shoulders were observed in older women compared with the younger women. Greater body cooling following cryostimulation was observed in the group of younger women particularly in the area of the lower limbs.

12

Zastosowanie termografii w diagnozowaniu i przewidywaniu uszkodzeń w elementach konstrukcyjnych maszyn i urządzeń

100%

Sucheta A. , Sikora K.

Mechanik

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2017

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tom R. 90, nr 11

1081--1083

PL

Przedstawiono zastosowanie termografii biernej (pasywnej) w diagnozowaniu błędów połączeń żeber z rurkami w grzejnikach konwekcyjnych, a także wykorzystanie kamery termowizyjnej do prognozowania miejsca wystąpienia zerwania elementu konstrukcyjnego poddanego działaniu naprężeń rozciągających.

EN

The use of passive thermography to diagnose defects in the connection of ribs with tubes in convection heaters, has been reported, as well as the use of thermal imaging cameras to predict the occurrence of breakage of a structural element subjected to tensile stress.

13

Laboratory methods for testing the performance of pyrotechnic delay elements

100%

Warchol R. , Nita M.

Scientific Journal of the Military University of Land Forces

|

2018

|

tom 50

|

nr 4(190)

101-115

EN

Pyrotechnic delay elements owing to their simple structure and reliability are very often used as part of the design of ammunition. Their basic task consists in generating a specified delay between the respective actions of two elements/systems, required to ensure the safe and reliable work of ammunition. The paper presents laboratory methods employed for testing the performance of pyrotechnic delay elements (PDEs) used in means of combat. The introductory part describes pyrotechnical delay elements and the task fulfilled by them in ammunition. The next part discusses performance parameters of pyrotechnic delay elements, decisive for their proper operation, and factors influencing such operation. In its main part the article presents the standard defining the laboratory methods to be employed for testing pyrotechnic delay elements. According to the above-mentioned standard, the laboratory methods of testing pyrotechnic delay elements can be divided into tests in the open and closed systems. Further, the paper discusses both types of test systems. Taking account of a wide thematic scope of the discussed issue, this article focuses mainly on presenting new methods of testing pyrotechnic delay elements, which have not been mentioned in the standard. Provided examples of tests of pyrotechnic delay elements have been taken from the Polish and foreign literature. Two methods of testing pyrotechnic delay elements are worth paying special attention, one making use of a thermal imaging camera, and the other relying on Roentgen radiation.

14

InAs/GaSb superlattice focal plane arrays for high-resolution thermal imaging

88%

Rehm R. , Walther M. , Schmitz J. , Fleißner J. , Fuchs F. , Ziegler J. , Cabanski W.

Opto-Electronics Review

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2006

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tom Vol. 14, No. 1

19-24

EN

The first fully operational mid-IR (3–5 um) 256x256 IR-FPA camera system based on a type-II InAs/GaSb short-period superlattice showing an excellent noise equivalent temperature difference below 10 mK and a very uniform performance has been realized. We report on the development and fabrication of the detector chip, i.e., epitaxy, processing technology and electro-optical characterization of fully integrated InAs/GaSb superlattice focal plane arrays. While the superlattice design employed for the first demonstrator camera yielded a quantum efficiency around 30%, a superlattice structure grown with a thicker active layer and an optimized V/III BEP ratio during growth of the InAs layers exhibits a significant increase in quantum efficiency. Quantitative responsivity measurements reveal a quantum efficiency of about 60% for InAs/GaSb superlattice focal plane arrays after implementing this design improvement.

15

Safety of Steel Arch Support Operation During Rock Bursts Under Explosive Atmosphere Conditions

88%

Pytlik A. , Frąc W.

Studia Geotechnica et Mechanica

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2023

|

tom Vol. 45, nr 2

144-157

EN

Methane and coal dust explosions are among the most common causes of disasters in hard coal mining. Therefore, it is important for occupational safety in hard coal mines operating under methane and coal dust explosion hazards to identify possible ignition sources, whether due to natural or technical factors. One technical source of ignition can be mechanical sparks generated during operation of mechanical equipment and high surface temperatures of equipment components during operation. This paper presents the methodology and results of thermal imaging and strength testing of roadway support elements under dynamic loading. The goal of the tests was to identify the potential explosive atmosphere ignition sources during the operation of the support under the conditions of rock bursts. The scope of testing encompassed the temperature measurements by means of thermal camera of friction prop and yielding support frame sliding joint elements at yield under dynamic impact loading (simulating a burst). Significant joint element heating and mechanical sparking was observed during the testing of arching yielding support frame sliding joints and straight friction prop joints as a result of friction at yield. Some of the aspects defined in standard PN-EN ISO80079-36:2016 include the maximum temperature T max =150°C for a surface that can accumulate a layer of coal dust. Tests of the friction joints have shown that during impact loading, numerous mechanical sparks are produced at the friction joints of sections of the steel prop, with the surface temperature of the sections starting from 169.6°C and reaching up to 234.1°C. During tests it was also to determined emissivites of the tested sliding joints constructed from V29-V32 secrions depending on corrosion products which consist in range 0.842-0.873. Such a high temperature can initiate an explosive mixture consisting of methane, air and coal dust.

16

Exogenous silicon application promotes growth and alleviates drought and salt stresses of rice plants

88%

Wongla W. , Theerakulpisut P. , Lontom W.

Acta Agrobotanica

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2023

|

tom 76

17

Application of a deep-learning neural network for image reconstruction from a single-pixel infrared camera

88%

Urbaś S. , Więcek B.

Opto-Electronics Review

|

2024

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tom Vol. 32, No. 1

art. no. e148877

EN

The article presents the simulation results of a single-pixel infrared camera image reconstruction obtained by using a convolutional neural network (CNN). Simulations were carried out for infrared images with a resolution of 80 × 80 pixels, generated by a low-cost, low-resolution thermal imaging camera. The study compares the reconstruction results using the CNN and the ℓ₁ reconstruction algorithm. The results obtained using the neural network confirm a better quality of the reconstructed images with the same compression rate expressed by the peak signal-to-noise ratio (PSNR) and structural similarity index measure (SSIM).

18

Real Time Thermal Imaging of Solid Oxide Fuel Cell

88%

Jasiński M. , Ziewiec K. , Wojciechowska M.

Archives of Metallurgy and Materials

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2019

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tom Vol. 64, iss. 4

1207--1212

EN

In this work, a mid infrared thermography was used to study thermal behavior of solid oxide fuel cell (SOFC) with a circular shape and a diameter of 90 mm. The emissivity of the anodic surface of the fuel cell was determined to be from 0.95 to 0.46 in the temperature range 550-1200 K and the profile and temperature distribution of the anodic surface of the unloaded cell was given. The surface temperature of the cell was determined during operation and the polarity changes from open circuit voltage (OCV) to 0.0 V. It was found that the cell self-heating effect decreases with increasing temperature of the cell.

19

Optimization of Animal Detection in Thermal Images Using YOLO Architecture

88%

Popek Ł. , Perz R. , Galiński G. , Abratański A.

International Journal of Electronics and Telecommunications

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2023

|

tom Vol. 69, No. 4

826--831

EN

The article presents research on animal detection in thermal images using the YOLOv5 architecture. The goal of the study was to obtain a model with high performance in detecting animals in this type of images, and to see how changes in hyperparameters affect learning curves and final results. This manifested itself in testing different values of learning rate, momentum and optimizer types in relation to the model’s learning performance. Two methods of tuning hyperparameters were used in the study: grid search and evolutionary algorithms. The model was trained and tested on an in-house dataset containing images with deer and wild boars. After the experiments, the trained architecture achieved the highest score for Mean Average Precision (mAP) of 83%. These results are promising and indicate that the YOLO model can be used for automatic animal detection in various applications, such as wildlife monitoring, environmental protection or security systems.

20

Experimental characterisation and modelling of the thermo-viscoplastic behaviour of steel AISI 304 within wide ranges of strain rate at room temperature

88%

Rusinek A. , Rodriguez-Martinez J. A. , Pesci R. , Capelle J.

Journal of Theoretical and Applied Mechanics

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2010

|

tom Vol. 48 nr 4

1027-1042

EN

In this investigation, thermo-viscoplastic behaviour of austenitic steel AISI 304 has been characterised in tension under wide ranges of strain rate at room temperature. This metal possesses an elevated strain hardening rate and ductility which enhance its capability for absorbing energy under mechanical loading. It has been observed that the rate sensitivity of the material is independent of plastic strain. Moreover, it has been noticed that beyond a certain level of loading rate the flow stress of the material sharply increases. In agreement with experimental evidences reported in the literature, this behaviour is assumed to be caused by the drag deformation mode taking place at high strain rates. Based on such considerations, the thermo-viscoplastic behaviour of the material has been macroscopically modelled by means of the extended Rusinek-Klepaczko model to viscous drag effects. Satisfactory matching has been found between the experiments and analytical predictions provided by the constitutive relation.

PL

W pracy scharakteryzowano termo-lepkosprężyste właściwości stali AISI 304 na podstawie prób rozciągania dla szerokiego zakresu prędkości odkształceń w temperaturze pokojowej. Stal ta posiada podwyższoną ciągliwość i stopień umocnienia odkształceniowego, które to cechy powiększają jej zdolność do pochłaniania energii mechanicznej. Zaobserwowano, że wrażliwość stali na tempo obciążeń jest niezależna od wartości odkształceń plastycznych. Co więcej, zauważono, że powyżej pewnej prędkości zmian obciążenia naprężenie płynięcia materiału gwałtownie rośnie. W zgodzie z rezultatami badań doświadczalnych opisanymi w literaturze założono, że zachowanie takie wywołane jest pojawieniem się tłumionej postaci deformacji charakterystycznej dla wysokich prędkości odkształcenia. Na podstawie przeprowadzonych badań zaproponowano makroskopowy model termo-lepkosprężystych właściwości stali w oparciu o rozszerzony model Rusinka-Klepaczki dla odzwierciedlenia efektu oporu wiskotycznego. Otrzymano zadawalającą korelację pomiędzy wynikami uzyskanymi z konstytutywnego modelu materiału oraz rezultatami badań doświadczalnych.