Pracownicy

Streszczenie:
In the paper the theoretical modeling of ultrasonic testing of railway rails with high scanning speed is considered. The model for the calculation of the ultrasonic field generated by the ultrasonic transducers and the pulse echo amplitude received after wave reflection at the defect is developed. The model is based on well-established principles of elastodynamic theory: the Rayleigh–Sommerfeld integral, the Auld reciprocity relation, and the Kirchhoff approximation. It forms the basis for design of computer program to simulate ultrasonic inspections of railway rails with automated mobile systems. The major innovation introduced in the model is taking into account the high scanning speed of the ultrasonic probes over the rail head and the limited repetition rate of the ultrasonic system. The mentioned aspects of the high-speed rail testing require the revision of one of the basic paradigms of the current ultrasonic models, which assume that the scanning speed of the ultrasonic probe is negligible in comparison to the speed of ultrasonic waves propagating in the tested material. Actually, when scanning rails at a speed of 120 km/h, the ultrasonic probe can change its position up to 5 mm between transmitting and receiving ultrasonic pulses reflected from defects located in the rail foot. Such a shift in the probe position is not negligible and should be considered in calculations. As a consequence, the ultrasonic system’s slow repetition rate and fast scanning speed can make it less likely that certain rail flaws will be found. To quantitatively examine the severity of these phenomena, the new ultrasonic model and related simulation software was developed.

Słowa kluczowe:
non-destructive testing, railway rails defects, testing of railway rails, automatic ultrasonic testing

Streszczenie:
In this paper, the key parameters influencing the proper operation of ultrasonic probes for railway rails diagnostics are determined. The goal is to test a set of ultrasonic probes under conditions occurring at high diagnostic speeds. Four issues are studied in more detail. The probe block-rail contact force required to obtain maximum echo level is determined. In the authors’ opinion, the key aspect is the design of the water irrigation nozzle shape in order to produce a laminar couplant flow under the probes. The dependence of the amplitude of the recorded echo on the coupling layer thickness is experimentally investigated. The population of registered signal samples is processed to determine the testing speed limit, which resulted from the loss of data validation ability. The speed limit is calculated based on the average value of the amplitude of the measured signal and the standard deviation of the registered population of amplitudes.
The conducted research allows the authors to conclude that the instrumentation they developed enables the recording of an ultrasonic signal propagating through the tested rail at scanning speed of up to 100 km/h

Słowa kluczowe:
railway rails diagnostics, ultrasonic examination, ultrasonic probe-rail interface

Streszczenie:
The paper presents the modeling of transmission of the ultrasonic plane wave through an uniform liquid layer. The considered sources of the ultrasonic wave were normal (straight) beam longitudinal wave probes and angle beam sheer waves probes commonly used in non-destructive testing. Coupling losses (CL) introduced by the presence of the coupling layer are discussed and determined applying the numerical procedure. The modeling applies to both monochromatic waves and short ultrasonic pulses with a specified frequency bandwidth. Model implementation and validation was performed using a specialized software. The predictions of the model were confirmed by coupling losses measurements for a normal beam longitudinal wave probe with a delay line made of polymethyl methacrylate (PMMA). The developed model can be useful in designing ultrasonic probes for high-speed rail track inspections, especially for establishing the optimal thickness of the water coupling layer and estimation of coupling losses, due to inevitable changes of the water gap during mobile rail inspection.

Słowa kluczowe:
non-destructive testing, ultrasonic examination, plane wave propagation

Streszczenie:
Symulacje komputerowe odgrywają coraz większą rolę w planowaniu, przygotowaniu oraz interpretacji badań ultradźwiękowych. W artykule opisano podstawowe założenia teoretyczne oraz funkcjonalności programu SymUT rozwijanego w pracowni badań nieniszczących IPPT PAN. W celu ilustracji możliwości programu pokazano proste przykłady jego zastosowania do obliczania rozkładów pola ultradźwiękowego głowic ultradźwiękowych oraz obwiedni echa wad modelowych. Opisano zasady wykorzystania programu do projektowania głowic ultradźwiękowych oraz przygotowania procedur badawczych
Computer simulations are playing an increasingly important role in planning, preparation and interpretation of ultrasonic testing. The article describes the basic theoretical assumptions and functionalities of the SymUT software developed in the non-destructive testing laboratory of IPPT PAN. In order to illustrate its capabilities, simple examples of its use for calculation of the ultrasonic field of ultrasonic probes as well as the echo envelopes from model defects are shown. The principles of using the program for designing of ultrasonic probes and preparing testing procedures are described

Słowa kluczowe:
badania ultradźwiękowe, defektoskopia ultradźwiękowa, wiązka ultradźwiękowa, wady materiałowe, symulacje badań ultradźwiękowych, ultrasonic testing, ultrasonic flaw detection, ultrasonic beam, material defects, ultrasonic testing simulations, radar testing, electromagnetic testing

Streszczenie:
Celem niniejszego referatu jest przedstawienie sposobów modelowania wad kontaktowo-zmęczeniowych wykorzystując komercyjne i autorskie oprogramowanie komputerowe. Szczególną uwagę zwrócono na poznanie sposobu rozwoju wad kontaktowo-zmęczeniowych czego efektem jest poprawne modelowanie wad uwzględniające takie czynniki jak: lokalizacja wady, kierunek propagacji pęknięcia. Wynikiem końcowym prac było opracowanie parametrów serii głowic ultradźwiękowych, które będą efektywnie wykrywać wady kontaktowo-zmęczeniowe w szyna kolejowych.

Słowa kluczowe:
UT, wady kontaktowo zmęczeniowe, modelowanie, szyny, oprogramowanie

Streszczenie:
The paper presents an investigation of the railhead steel R260. Brinell hardness was measured, spherical microindentation tests were performed and the microstructure was analysed using optical microscopy and SEM images. Fatigue damage in various near-surface regions of the railhead was estimated on the basis of local deterioration of elastic modulus and the development of plastic work in cyclic microindentation tests. There is a clear difference in hardness and fatigue damage between the used and the virgin regions of the railhead. The Brinell hardness and ultrasonic measurements show a change in material properties due to rail manufacturing process.

Słowa kluczowe:
Fatigue damage, Microindentation, Brinell hardness, Ultrasonic measurements, Railhead

Streszczenie:
In the paper the calculation of ultrasonic field generated by the transmitting transducer and the energy of the beam returning after the reflection at the defect in the rail volume is presented. The focus of the authors is directed on the specific transducer - defect configurations where the common methods of determination of ultrasonic beam trajectory fails. To solve this problem the refraction effexts are studied and its impact is calculated.

Słowa kluczowe:
non-destructive testing, rolling contact fatigue damage, ultrasound

Streszczenie:
Podstawową techniką stosowaną w badaniach laminatów węglowych metodą Phased Array jest kontaktowa metoda echa z ręcznym przesuwem głowicy. Pod względem mobilności i uniwersalności jest to technika zbliżona do konwencjonalnych badań defektoskopowych ze zobrazowaniem typu A, zapewniająca jednak pełny zapis wyników badania oraz znacznie większe możliwości ich analizy.

Słowa kluczowe:
badania ultradźwiękowe, technika phased array, wady laminatów węglowych, typy zobrazowań PA

Streszczenie:
Badania ultradźwiękowe są obecnie podstawową metodą badań nieniszczących materiałów i struktur kompozytowych stosowanych w przemyśle lotniczym. W badaniach wykonywanych na etapie produkcji części i zespołów kompozytowych największe znaczenie mają zautomatyzowane techniki ultradźwiękowe oparte na metodzie przepuszczania, nazywane w branży lotniczej technikami C-scan. Pozwalają one w szybki i wydajny sposób badać zarówno laminaty monolityczne jak i struktury przekładkowe o różnej grubości i budowie dając w wyniku zobrazowania typu C badanych części. Podstawowe zasady działania systemów C-scan oraz przykłady ich praktycznego stosowania opisano w pracy.

Słowa kluczowe:
badania ultradźwiękowe, technika phased array, kompozyty węglowe, wady kompozytów

Streszczenie:
The paper describes two different techniques of ultrasound measurements performed in fibre cement boards, the material widely applied in building technology. An in-house device dedicated for fibre-cement board testing is also presented. To overcome the difficulty of determining the arrival time of the waveform of a longitudinal wave travelling across a thin and inhomogeneous body, a cross-correlation method of signal processing was proposed and applied

Słowa kluczowe:
ultrasound, fibre-cement board, waveform cross correlation coefficient

Streszczenie:
The purpose of this article is to present the most important requirements and problems related to periodic inspection of ultrasonic flaw detectors in accordance with requirements of standard PN-EN12668-1: 2010. Particular attention has been paid to the measurement of ultrasonic flaw detector parameters and requirements concerning specialist measuring equipment. The form of ultrasonic flaw detector certificate was proposed, which specifies all tests of group 2 of PN-EN12668-1: 2010. The proposed certificate confirms the compatibility of the flaw detector with the speci­fied standard and the test group under which the equipment was tested.

Słowa kluczowe:
characterization, verification, calibration, flaw, detector