The article addresses results of analyses of design solutions and materials commonly used in gas springs for hydropneumatic suspension systems. The authors have discussed main advantages resulting from application of such a design solution in passenger car suspension systems. Fundamental correlations defining the parameters characterising a gas spring with constant gas mass have been referred to. Also materials used in the manufacture of selected gas spring elements have been described
Ł. Konieczny, R. Burdzik and T. Węgrzyn
J. Konieczny, K. Labisz, K. Głowik-Łazarczyk, J. Ćwiek and Ł. Wierzbicki
In Poland, researchers have a very strong interest in archaeometallurgy, which, as presented in classical works, focuses on dating artefacts from the prehistoric and early medieval periods in the form of cast iron and copper castings. This study, extending the current knowledge, presents the results of a microstructure investigation into the findings from the Modern era dating back to the late Middle Ages. The investigated material was an object in the form of a heavy solid copper block weighing several kilograms that was excavated by a team of Polish archaeologists working under the direction of Ms Iwona Młodkowska-Przepiórowska during works on the marketplace in the city of Czestochowa during the summer of 2009. Pre-dating of the material indicates the period of the seventeenth century AD. The solid copper block was delivered in the form of a part shaped like a bell, named later in this work as a “kettlebell”. To determine the microstructure, the structural components, chemical composition, and homogeneity, as well as additives and impurities, investigations were carried out using light microscopy, scanning electron microscopy including analysis of the chemical composition performed in micro-areas, and qualitative X-ray phase analysis in order to investigate the phase composition. Interpretation of the analytical results of the material’s microstructure will also help modify and/or develop new methodological assumptions to investigate further archaeometallurgical exhibits, throwing new light on and expanding the area of knowledge of the use and processing of seventeenth-century metallic materials.
R. Burdzik, T. Wegrzyn, Ł. Konieczny and A. Lisiecki
The paper presents results of research on influence of fatigue metal damage of the inner race of bearing on vibration in different frequencies. The active diagnostics experiments were conducted on application of vibroacoustics methods for technical condition monitoring. Provides an overview of materials and process analysis of rolling bearings wear. The bearing damage of the inner race have been simulating. The research was conducted on special research-educational test bench for vibration monitoring for rotaring machinery. For the identification of the symptoms of the defects in the vibration signal the analysis of time realization and frequency transformation of the vibration have been conducted. For the comparison of the vibration of good and damage bearings signals registered for different frequencies have been presented in form of spectrograms and RMS distributions.
R. Burdzik, Ł. Konieczny, Z. Stanik, P. Folęga, A. Smalcerz and A. Lisiecki
The paper provides an analysis of the reasons for excessive wear of the camshafts system components based on models developed to describe the impact of selected material, technological and operational factors. The subject of the research was wear of camshaft cams studied in accordance with results of operation tests. Based on the said tests, the dependence of wear intensity of cams from their angular position was established. The respective calculation results enabled the function of cam fallibility to be determined.
A.M. Wittek, R. Burdzik, P. Folęga, Ł. Konieczny and B. Łazarz
The paper presented results of the research on process of production of highly important element of passenger car. The main object of the research was influence of production process and material factors on fatigue strength of tubular stabilizer bar. The scope of the research included the stabilizer bar hot bent at the bending table, hardened in oil and tempered. The bending radii I, II and III were metalographically tested. The stabilizer bar was also subjected to fatigue tests. For analysis purpose the finite element method (FEM) calculation have been conducted. The analysis of relationship of outer diameter to wall thickness is very important. The analysed bar has broken early. The paper presents the reasons for premature failure of the tubular stabilizer bar.
A. Lisiecki, R. Burdzik, G. Siwiec, Ł. Konieczny, J. Warczek, P. Folęga and B. Oleksiak
Autogenous laser welding of 0.8 mm thick butt joints of car body electro-galvanized steel sheet DC04 was investigated. The Yb:YAG disk laser TruDisk 3302 with the beam spot diameter of 200 μm was used. The effect of laser welding parameters and technological conditions on weld shape, penetration depth, process stability, microstructure and mechanical performance was determined. It was found that the laser beam spot focused on the top surface of a butt joint tends to pass through the gap, especially in the low range of heat input and high welding speed. All test welds were welded at a keyhole mode, and the weld metal was free of porosity. Thus, the keyhole laser welding of zinc coated steel sheets in butt configuration provides excellent conditions to escape for zinc vapours, with no risk of porosity. Microstructure, microhardness and mechanical performance of the butt joints depend on laser welding conditions thus cooling rate and cooling times. The shortest cooling time t8/5 was calculated for 0.29 s.
R. Burdzik, A. Lisiecki, J. Warczek, Ł. Konieczny, P. Folęga, A. Szkliniarz and G. Siwiec
The article addresses a method proposed for comprehensive research of vibration properties dedicated to new structural materials. The method in question comprises three-stage studies, thus enabling the related costs to be reduced on each stage of the process. Subjects of identification and assessment are both the properties and the material structure as well as numerically determined dynamic characteristics and actual vibration characteristics of materials. The article provides preliminary research results obtained for Cu-2Ti-1Co and Cu-6Ti-1Co alloys, the mechanical properties of which are very prospective. An additional advantage of the method proposed is the capability of identifying alloy types by application of non-destructive vibratory methods.