Friction coefficient determination based on the results of ball – on - flat test

• Autorzy: Szymczyk E. , Jachimowicz J. , Prasek Ł.
• Języki publikacji: EN

Abstrakty

EN

The interaction of contacting surfaces in relative motion is basic for every engineering design. The transmission of load from one rubbing surface to its mating surface under conditions of dry contact is taken into account. Microlocal or global models of friction are used to describe this phenomenon. In global approach, frictional force is proportional to normal load. A coefficient of external friction depends on the type, shape, and precision of finishing the surfaces of mating elements. The aim of the paper is analysis of a friction coefficient for 2024T3 aluminium alloy during cyclic tangential loading. Experimental tests are carried out on a ball-on-flat wear-testing machine Ducom. Tests of reciprocating friction are carried out using the following friction pairs of specimens: the ball specimen is made of high strength aluminium alloy PA25 and the plane specimen is made of 2024T3 alloy. Finally, graphs of temporary friction coefficients versus time in the form of fluctuated periodical functions are obtained. Two phases of friction are detected. However, during the first stage, the friction coefficient is relatively small while in the second period it rapidly increases and tends to become more irregular. Static and dynamic friction coefficients are estimated. In order to determine the dynamic coefficient the Discrete Fourier Transformation is used. The calculation of the dominant amplitude (corresponding to test frequency) of the studied functions is possible due to this method. An increase of the friction coefficient with an increase of normal load is observed. A cladding layer also causes an increase of friction, especially in the second phase.

Słowa kluczowe

EN

friction coefficient; ball-on-flat test; FFT

• Wydawca: Łukasiewicz Research Network - Institute of Aviation ; European Science Society of Powertrain and Transport KONES Poland ; Wydawnictwo Instytutu Technicznego Wojsk Lotniczych
• Czasopismo: Journal of KONES
• Rocznik: 2012
• Tom: Vol. 19, No. 1
• Strony: 415--422
• Opis fizyczny: Bibliogr. 8 poz., rys.

Twórcy

autor

Szymczyk E.

autor

Jachimowicz J.

autor

Prasek Ł.

• Military University of Technology Department of Mechanics and Applied Computer Science Gen. Sylwestra Kaliskiego Street 2, 00-908 Warsaw, Poland tel.: [phone], fax: [phone],

Bibliografia

• [1] Stolarski, T. A., Tribology in machine design, Butterworth-Heinemann Oxford 1990/2000
• [2] Popov, V. L., Contact Mechanics and Friction, Physical Principles and Applications,Springer-Verlag 2010.
• [3] Endo, H., Marui, E., Effect of reciprocating and unidirectional sliding motion on the friction and wear of copper on steel, Wear 249, pp. 582–591, 2001.
• [4] Jachimowicz, J., Kaniowski, J., Szymczyk, E., Kozłowski, P., Moneta, G., Zjawisko frettingu w konstrukcjach lotniczych, Transaction of ILOT, 206, 4, pp. 36-38, 2010.
• [5] Zmitrowicz, A., Wear patterns and laws of wear - a review, Journal of theoretical and applied mechanics 44, pp. 219-253, Warsaw 2006.
• [6] Müller, R., An experimental and numerical investigation on the fatigue behaviour of fuselage riveted lap joints, Doctoral Dissertation, Delft University of Technology, 1995.
• [7] Szolwinski, M. P., The mechanics and tribology of fretting fatigue with application to riveted lap joints, West Layfayette, IN, USA Purdue University, USA 1998.
• [8] Metals Handbook, Vol. 18, ASM, 8th Editions, 1992. 422