Wyniki wyszukiwania - BazTech

1

Możliwości oceny stanu naprężeń w szynach toru bezstykowego

Towpik K.

Archiwum Instytutu Inżynierii Lądowej

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2017

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Nr 25

407--417

PL

W referacie scharakteryzowano złożony stan naprężeń (sił podłużnych) w szynach eksploatowanego toru bezstykowego. Głównym źródłem naprężeń są zmiany temperatury szyn, współdziałanie pojazdu z torem oraz naprężenia własne będące efektem procesu produkcji. Znajomość rozkładu naprężeń w szynach ma istotne znaczenie dla oceny bezpieczeństwa eksploatowanego toru bezstykowego oraz zrozumienia rozwoju defektów szyn. Omówiono również metody pomiaru naprężeń (sił podłużnych) w szynach.

EN

In the paper the variability of stresses (and corresponding longitudinal forces) observed in continuous welded rail (CWR) during service were described. The main sources of stresses are rail temperature changes, train/track interaction and residual stresses resulted from the manufacturing process. A knowledge of stress distribution in rails is very important for CWR track safety assessment in service and essential for understanding the rail defects development. The different methods of stress (longitudinal forces) measurements in rails were also presented.

2

X-Ray Diffraction Measurements for Riveted Joints. The Application of a Novel Methodology

Gadalińska E., Kaniowski J.

Fatigue of Aircraft Structures

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2012

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Iss. 4

17--28

EN

The X-ray diffraction method is the best, widely available, non-destructive measurement method used to determine the residual and load stresses in crystalline materials. This method can be applied without any limitations to flat specimens. Depending on the equipment geometry, the type of material and geometry of the specimen, there are many limitations, restrictions and recommendations which have to be fulfilled to obtain reliable results. This was the reason for working out a methodology for X-ray diffraction stress measurements for riveted specimens.The first case to analyze is the necessity of choosing an X-ray tube suitable for the specimen material which will give the diffraction peaks in the range of 2Θ angles between 120° and 180°. Afterwards it is crucial to make the best selection of Bragg's angle 2Θ. In the vast majority of cases the best selection is the possibly biggest 2Θ angle because of the best accuracy of the measurement. However, for example for aluminum alloys (for CrKα radiation), this choice is not so obvious. It is much more convenient to perform measurements not for the highest diffraction angle. The best selection in this case is 2Θ=139,3°, and not 156,7°. Other selections which are necessary to be made before measurements are the collimator diameter, time of exposure, ψ tilts and φ oscillations. The proper selection of these parameters is crucial for the fast and efficient performing of measurements and for obtaining reliable results. Before performing the measurement, especially in the case of the specimen with complicated geometry (for example in the case of riveted specimens made of aluminum alloys), it is necessary to analyze the results obtained paying special attention to the possibility of the appearing of the rivet head/driven rivet head shadow during the measurement. The work describes differences between the X-ray stress measurement results obtained without any interference and the results received after eliminating the selected diffraction peaks for which the shadow of rivet head/driven rivet head has appeared.

3

Tensometryczny przetwornik typu "inkluzja sztywna" do pomiaru zmian naprężeń w górotworze

Haładewicz M.

Cuprum : czasopismo naukowo-techniczne górnictwa rud

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2010

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nr 1

45-52

PL

Przedstawiono wyniki prac badawczych KGHM CUPRUM sp. z o.o. - CBR, w ramach których opracowano, wykonano i przebadano tensometryczny przetwornik do ciągłych pomiarów zmian naprężeń in situ w górotworze skalnym. Przetwornik ten należy do grupy przetworników ze "sztywną inkluzją", które charakteryzują się tym, że zbudowane są z materiału o module sprężystości Es wielokrotnie większym niż skała. W artykule opisano budowę przetwornika, gdzie pokazano sposób zamontowania tensometrów i elektroniki wewnątrz stalowego cylindra pomiarowego oraz wygląd rzeczywisty wykonanych modeli. Przedstawiono główne dane techniczne oraz otrzymane charakterystyki prądu wyjściowego przetwornika w funkcji naprężenia w próbce skalnej i aluminiowej. Artykuł podaje proponowane sposoby przesyłu sygnału z przetwornika do systemów dyspozytorskich, istniejących w kopalniach LGOM.

EN

The article presents the results of research works conducted in KGHM CUPRUM Ltd. R&D Centre, which include engineering and examination of the strain gauge transducer for continuous in situ measurements of stress changes in the rock. This is a "rigid inclusion" gauge, made of a material with an elastic modulus Es much greater than the rock modulus. In the paper, a construction of the transducer is described, showing how the foil strain gauges and an electronic board are mounted inside a hollow steel cylinder as well as the view of produced models. It also presents general technical data of the transducer and characteristics of output current signal vs. stress changes in the rock and Al block samples. Proposed ways of transmitting transducer output signals to control rooms in the LGOM mines are included.

4

Measurement of stress as a function of temperature in Ag and Cu thin films

Prószyński A., Chocyk D., Gładyszewski G., Pieńkos T., Gładyszewski L.

Optica Applicata

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2005

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Vol. 35, nr 3

517-522

EN

Stress measurements of 23 nm copper films and 93 nm silver films on Si (100) have been performed during thermal cycling between RT and 450°C. The changes in stress versus temperature are interpreted. The effects of treatment on microstructure and composition are studied by X-ray diffraction.