dr inż. Grzegorz Starzyński

Zakład Mechaniki Materiałów (ZMM)
Pracownia Warstwy Wierzchniej (PWW)
stanowisko: główny specjalista
telefon: (+48) 22 826 12 81 wew.: 261
pokój: 230
e-mail: gstarz

Doktorat
1998Naturalna warstwa wierzchnia metali - opis fizyczny i model fenomenologiczny 
promotor -- prof. dr hab. inż. Wiktor L. Gambin, IPPT PAN
541 
Ostatnie publikacje
1.Kucharski S., Starzyński G., Study of contact of rough surfaces: Modeling and experiment, WEAR, ISSN: 0043-1648, DOI: 10.1016/j.wear.2014.01.009, Vol.311, pp.167-179, 2014

Streszczenie:

In the paper a problem of contact of rough surface with rigid flat plane is investigated experimentally and numerically. Samples made of three different steels with roughness constituted in a sand-blasting process were compressed in a special experimental setup. 3D surface topographies were measured in initial and deformed state using scanning profilometry. An experimental procedure has been designed that enables specifying load-approach and load-real contact area relations corresponding to plastic deformation of roughness zone. These relations were also simulated using a simple model based on statistical approach with special procedure proposed for a proper specification of sampling interval. The experimental and numerical results have been compared.

Słowa kluczowe:

Contact mechanics, Roughness, Real contact area, Asperity definition, Sampling interval

Afiliacje autorów:

Kucharski S.-IPPT PAN
Starzyński G.-IPPT PAN
35p.
2.Starzyński G., Buczkowski R., Ultrasonic Measurements of Contact Stiffness Between Rough Surfaces, Journal of Tribology, ISSN: 0742-4787, DOI: 10.1115/1.4027132, Vol.136, pp.034503-1-5, 2014

Streszczenie:

We have used an ultrasonic method to determine the normal and shear stiffness for three different surfaces. The degree of hysteresis for the loading/unloading and stiffness ratio is a function of roughness. Nonlinear contact stiffness characteristics are obtained. The ratio of tangential to normal stiffness KT/KN slowly increases in proportion to normal loading. The novelty of our setup is that at the same time we can measure the reflection coefficient, obtain results for three transducers simultaneously, and measure the approach as a function of load. The presented experimental results of normal contact stiffness measurements have been used for the verification of our theoretical model based on a fractal description of rough surfaces (Buczkowski et al., “Fractal Normal Contact Stiffness of Rough Surfaces,” Arch. Mech. (submitted for publication).

Słowa kluczowe:

Surface roughness, Stress, Reflectance, Stiffness, Ultrasonic measurement, Waves

Afiliacje autorów:

Starzyński G.-IPPT PAN
Buczkowski R.-Maritime University of Szczecin (PL)
25p.
3.Buczkowski R., Kleiber M., Starzyński G., Normal contact stiffness of fractal rough surfaces, ARCHIVES OF MECHANICS, ISSN: 0373-2029, Vol.66, No.6, pp.411-428, 2014

Streszczenie:

We used the fractal theory based on a single variable Weierstrass–Mandelbrot function to obtain the normal contact stiffness if rough and smooth isotropic surfaces are pressed against each other. Because in the original fractal theory the distribution of contact area is assumed geometrically, we propose the method in which the actual deformation of asperities and a correction due to asperity coupling (interaction) will be taken into account. This correction is equivalent to an increase of the effective separation by a quantity proportional to the nominal pressure and it has a significant effect on contact stiffness at larger normal loads (low separations). The numerical results demonstrate a nonlinear evolution of the contact stiffness with the normal load in particular in the first stage of loading at low squeezing pressures. We have compared the results of the theoretical contact stiffness using the fractal method with the experimental ultrasonic measurements. Experimental results made on real surfaces agree remarkably well with the theoretical predictions.

Słowa kluczowe:

fractal model, contact stiffness, ultrasonic measurements

Afiliacje autorów:

Buczkowski R.-Maritime University of Szczecin (PL)
Kleiber M.-IPPT PAN
Starzyński G.-IPPT PAN
25p.
4.Starzyński G., Mackiewicz S., Szelążek J., Wykorzystanie współczynnika odbicia fal ultradźwiękowych do oceny kontaktu powierzchni chropowatych, INŻYNIERIA MATERIAŁOWA, ISSN: 0208-6247, Vol.192, No.2, pp.71-79, 2013

Słowa kluczowe:

badania ultradźwiękowe, pomiary współczynnika odbicia, ocena powierzchni kontaktu, pomiary chropowatości

Afiliacje autorów:

Starzyński G.-IPPT PAN
Mackiewicz S.-IPPT PAN
Szelążek J.-IPPT PAN
7p.
5.Starzyński G., Modeling and experimental verification of simultaneous tension and torsion in cylindrical element with surface layer, INTERNATIONAL JOURNAL OF FATIGUE, ISSN: 0142-1123, DOI: 10.1016/j.ijfatigue.2010.01.007, Vol.32, pp.1255-1264, 2010

Streszczenie:

This paper presents a simulative method which takes into consideration the influence of a surface layer on the stresses observed during low-cycle fatigue regions of tension and torsion and after loadings. The cyclic loading model is described for an axial-symmetric cylinder with a surface layer. The layer is divided into several zones (shells), which enable the introduction of material property changes and residual stresses as a function of the distance from the surface. This work also introduces a comparison of the evolution of residual stresses counted and measured experimentally with shot peened samples after cyclic tension and torsion. The experimental results agree well with the simulation.

Słowa kluczowe:

Fatigue modeling, Residual stresses, Tensile loading, Torsional loading, Surface treatments

Afiliacje autorów:

Starzyński G.-IPPT PAN
32p.
6.Kucharski S., Starzyński G., Bartoszewicz A., Prediction of surface roughness in metal forming with liquid lubricant, TRIBOLOGY INTERNATIONAL, ISSN: 0301-679X, DOI: 10.1016/j.triboint.2009.04.028, Vol.43, pp.29-39, 2010

Streszczenie:

In the paper an experimental study of compression of rough surface in the presence of lubricant and in dry state is presented. The evolution of roughness parameters was analyzed. In the lubrication conditions an existence of asymptotic state was observed where roughness parameters and real contact area stabilize due to hydrostatic response of lubricant. The simplified model was proposed allowing to predict the roughness parameters and real contact area of the deformed surface in the asymptotic state. The model is based on analysis of topography of the undeformed surface and compression of a singular lubricant pit. The analysis was performed both numerically and experimentally.

Słowa kluczowe:

Hydrostatic lubrication, Normal contact, Surface topography

Afiliacje autorów:

Kucharski S.-IPPT PAN
Starzyński G.-IPPT PAN
Bartoszewicz A.-IPPT PAN
32p.
7.Starzyński G., Kucharska B., Nitkiewicz Z., Ocena relaksacji naprężeń powierz-chniowych w stali po statycznym i cyklicznym odkształceniu, INŻYNIERIA MATERIAŁOWA, ISSN: 0208-6247, Vol.3, No.151, pp.467-470, 2006
8.Kucharski S., Starzyński G., Symulacja wpływu nagniatania na ewolucję naprężeń i trwałość zmęczeniową elementu z warstwą wierzchnią, PRZEGLĄD MECHANICZNY, ISSN: 0033-2259, Vol.3, pp.23-27, 2005

Prace konferencyjne
1.Starzyński G., Szelążek J., Mackiewicz S., Badania współczynnika odbicia i sztywności kontaktowej powierzchni chropowatych przy pomocy fal ultradźwiękowych, XVI Seminarium Nieniszczące Badania Materiałów, 2010-03-09/03-12, Zakopane (PL), pp.53-66, 2010
2.Mackiewicz S., Starzyński G., Szelążek J., Współczynnik odbicia od rzeczywistych powierzchni stylu, XVI Seminarium Nieniszczące Badania Materiałów, 2010-03-09/03-12, Zakopane (PL), pp.39-52, 2010
3.Szelążek J., Mackiewicz S., Starzyński G., Zastosowania pomiarów współczynnika odbicia fal ultradźwiękowych od granicy metal-metal w technice, XVI Seminarium Nieniszczące Badania Materiałów, 2010-03-09/03-12, Zakopane (PL), pp.67-82, 2010