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SPECIAL ISSUE
CONTENTS
| Stanisław Adamczak - Guest Editorial |
207 |
| Dariusz Janecki, Krzysztof Stępień - Applying normalized cross correlation function to the comparison of cylindricity profiles |
209 |
| Stanisław Adamczak, Dariusz Michalski - Statistical methods for comparison of measuring instruments accuracy |
221 |
| Włodzimierz Makieła - Determining Circular profiles by means of linear equations |
235 |
| Edward Miko - An analysis of the roughness of flat surfaces generated by end-milling cutters |
245 |
| Magdalena Piasecka, Mieczysław E. Poniewski - Liquid crystal thermography applied to investigations into heat transfer in minichannels |
259 |
| Stanisław Adamczak, Tadeusz Orzechowski, Tomasz L. Stańczyk - Application of the thermovision method to the assessment of roundness profiles of elements in motion |
275 |
| Sławomir Spadło, Piotr Gutkiewicz - Computer system for diagnosing adhesive joints in laminar composites by ultrasonic flaw detection method |
285 |
| Dariusz Ozimina, Michał Styp-Rekowski - Measurements of rolling friction resistance level in special rolling bearings |
295 |
ABSTRACTS
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DARIUSZ JANECKI, KRZYSZTOF STĘPIEŃ
Kielce University of Technology
The Faculty of Mechatronics and Machinery Design
APPLYING THE NORMALIZED CROSS CORRELATION FUNCTION TO THE COMPARISON OF CYLINDRICITY PROFILES
In practice, differences between cylindricity profiles of machine parts have been evaluated either visually or by comparing the values of selected cylindricity parameters. Since visual assessment of profile coincidence is approximate and qualitative in character, and the point-based comparison of numerical values of selected cylindricity parameters is often insufficient, a new approach to the problem has become necessary. The main assumption of the method is that by using the normalized cross correlation function, it is possible to determine the coefficient of profile coincidence, to carry out quantitative assessment of this coincidence, and, finally, to represent the profiles in one graph. By applying the Legendre/Fourier type of approximation, we obtain a universal from of the normalized cross correlation function, which permits us to compare cylindicity profiles registered by means of different measuring strategies, different measuring devices.
Keywords: measurement, cylindricity, approximation, profile comparison
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STANISŁAW ADAMCZAK, DARIUSZ MICHALSKI
Kielce University of Technology
Chair of Mechanical Engineering and Metrology
STATISTICAL METHODS FOR COMPARISON OF MEASURING INSTRUMENTS ACCURACY
The modern apparatus permits converting profile irregularities to electrical or optical signals. The amplified signals can be transformed from the analog to digital form and recorded as diagrams in rectangular or polar coordinates. A converted and registered profile is used for the assessment of surface geometry by means of numerical values of the predetermined parameters. In many a case, however, the parameters are point-based, so the assessment of the measured profile of a real surface is not objective, and neither is it explicit. This is particularly important when determining the accuracy of measuring instruments. The authors suggest that the problem can be solved applying three methods of computation employing the Pearson and Spearmen correlation coefficients, the cross correlation function, and the experimental method error.
Keywords: measurement, accuracy, measuring instrument, correlation
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WŁODZIMIERZ MAKIEŁA
Kielce University of Technology
DETERMINING CIRCULAR PROFILES BY MEANS OF LINEAR EQUATIONS
Software, the key element of a coordinate machine, is always kept secret from a user. It cannot be employed for research purposes, either. In order to perform simulations, for example, similar programs have to be developed. Such non-original software designed to suit individual needs is based on specific assumptions. If the equations of curves approximating measurement results are to be adjusted, it is often necessary to solve a system of nonlinear equations. To illustrate the problem of determination of curvilinear profiles, a circular profile is used. The method described here involves introducing simplifications that lead to linear equations.
Keywords: coordinate machines, circular profiles, curvilinear profiles, linear equations, absolute error, relative error
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EDWARD MIKO
Kielce University of Technology
AN ANALYSIS OF THE ROUGHNESS OF FLAT SURFACES GENERATED BY END-MILLING CUTTERS
This paper is concerned with the influence of the cutting speed on the longitudinal and lateral irregularities of flat surfaces sculptured with a CNC milling machine. A scanning microscope was used for registering and analysing the morphology of milled surfaces. SEM photographs of surfaces with longitudinal and lateral profiles are included and analysed. The measurements and the complex profile analyses discussed here were performed on a computer-aided test stand. It has been established that the effect of the cutting speed on the roughness of surface profiles is significant. The parameters related to the roughness height and shape are greater for a longitudinal profile than for a lateral one.
Keywords: surface roughness, lateral profile, longitudinal profile, frequency analysis
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MAGDALENA PIASECKA, MIECZYSLAW E. PONIEWSKI
Kielce University of Technology
e-mail: tmpmj@tu.kielce.pl
LIQUID CRYSTAL THERMOGRAPHY APPLIED TO INVESTIGATIONS INTO HEAT TRANSFER IN MINICHANELS
The paper presents the measurement set-up for the calibration of thermosensitive liquid crystals, which aims at determining the relation between a hue and a corresponding surface temperature. We also discuss the technique of spreading a liquid crystal layer over the surface. The calibration method, including its inconveniences, is discussed in details. The analysis of experimental results is given. The accuracy of temperature measurements on the surface with liquid crystal thermography is estimated. The examples of the measurement technique application to investigations into boiling heat transfer in the flow through a minichannel are provided.
Keywords: temperature measurement, liquid crystals thermography, minichannel
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STANISŁAW ADAMCZAK, TADEUSZ ORZECHOWSKI, TOMASZ L. STAŃCZYK
Kielce University of Technology, Poland
APPLICATION OF THE THERMOVISION METHOD TO THE ASSESSMENT OF ROUNDNESS PROFILES OF ELEMENTS IN MOTION
On the example of automotive drum brakes the application of the thermovision method to measurements of roundness profiles of elements in motion has been presented. In the paper the distribution of temperature along the external circumference of the drum measured using the thermovision technique has been compared with shape profiles of the inner surface of the drum. It has been proved that for the investigated automotive brake drums, the coefficient of correlation according to Pearson is always greater than 0.8. Such a value of this coefficient means that the correlation between the temperature of the outer surface of the drum and the shape profile of the inner surface is high. The measurements carried out during the experiment support the thesis that the temperature signal may be used for the assessement of geometrical structure of machine elements which are in motion.
Keywords: thermovision, roundness, drum, brake
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SŁAWOMIR SPADŁO1, PIOTR GUTKIEWICZ2
1Politechnika Świętokrzyska
Katedra Pojazdów i Sprzętu Mechanicznego, Kielce, Polska
e-mail: sspadlo@tu.kielce.pl
2Polska Akademia Nauk
Instytut Podstawowych Problemów Techniki, Warszawa, Polska
COMPUTER SYSTEM FOR DIAGNOSING ADHESIVE JOINTS IN LAMINAR COMPOSITES BY ULTRASONIC FLAW DETECTION METHOD
The article presents the arrangement and components of a computer measurement setup used to examine adhesive joints of thin-walled metal casings with laminar composites. The system makes it possible not only to measure, record and analyze the ultrasonic signal but also to present a graphical representation of the examination results. The use of special so-called broadband probes which generate very short (0.2 µs) pulses of longitudinal waves has made it possible to observe the influence which the quality of the bonding of the composite layer with the thin-walled steel casing has on the conditions of ultrasonic wave propagation (inside the steel casing).
Keywords: laminar composites, adhesive - bonded joints, ultrasonic inspection
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DARIUSZ OZIMINA1, MICHAŁ STYP-REKOWSKI2
1Technical University Kielce
Department of Mechatronic and Machine Building,
2Technical and Agricultural University Bydgoszcz
Mechanical Department
MEASUREMENTS OF ROLLING FRICTION RESISTANCE LEVEL
IN SPECIAL ROLLING BEARINGS
One-track vehicles are very popular and important transport facilities. Representative example can be bicycles which more than 20 million each year are produced worldwide. Because source of motive energy in these vehicles are human muscles, problem of energy conversion, as measured by their resistance to motion, is critical.
The main aim of the worked out experiments was to measure value of friction resistances and on the ground of them to find a mathematical models describing the relation between resistance to motion in the bicycle bearing and some of the constructional features: geometrical coefficient of adjoint, axial load and hardness of raceways in given test conditions. The experiments were made on an original bearing's test stand. Its construction and principles of operation were also described.
Keywords: bicycle bearing, constructional features, resistance to motion
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