Mechanics
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ISSN 1734-8927
e-ISSN: 2300-7060
Issue Date
2005
Volume
Vol. 24
Number
No. 3
Description
Journal Volume
Mechanics
Vol. 24 (2005)
Projects
Pages
Articles
Trzydziesta rocznica śmierci profesora Władysława Bogusza
(Wydawnictwa AGH, 2005) Engel, Zbigniew
Analiza przyczyn powstawania pęknięć zmęczeniowych w konstrukcji bębna pędnego maszyny wyciągowej
(Wydawnictwa AGH, 2005) Cichociński, Andrzej; Ładecki, Bogusław
Still in use today there are some hoisting mining machines with motion wheels, the construction of which uses ri-gid 'U' shaped diaphragms to connect side disks. In such wheels periodically, after servicing, fatigue cracks are being found. The authors performed strength analysis done by the finite elements method, and verified its results using appropriate tensammetric measurements. The measurements and analyses performed confirmed that direct cause of the fatigue cracks in the barrels is over-rigidity of the structure due to stiff diaphragms joining the wheel disks. Based on this, recommendations were issued regarding modernization of motion wheels in the discussed ho-isting machines.
Acoustic properties of the selected churches in Poland
(Wydawnictwa AGH, 2005) Engel, Zbigniew; Kosała, Krzysztof
The assessment ofthe acoustic properties of interiors of sacral buildings was, for many years, done by means of methods developed primarily for assessing concert halls, opera houses or auditoriums adapted for sacral buildings. Those are Beranek's, Ando's, RASTI and impulse methods. The paper provides short description of those methods as well as their yerification performed by the authors and graduate students of the Chair of Mechanics and Vibroacoustics AGH in several roman catholic churches in Poland. The analysis of those methods proved that - when applied to sacral objects - they are often not complete and must be supplemented. Regardless of numerous papers concerning investigations and creation of acoustic conditions in sacral objects, there is a lach of a uniform, specific method which would allow to assess the acoustic ąuality of such interiors. The new index method, which assesses the acoustic properties of sacral objects by a single-numbered - the global index of acoustic quality - is presented shortly in the paper. This global index is a function of several partial indices, namely: reverberation index, intelligibility of speech index, uniformity of loudness index, external disturbance index and musie sound ąuality index. The index method was applied and yerified in five roman catholic churches in Poland.
Badania charakterystyk aerodynamicznych profilów konstrukcji Witolda Kasprzyka
(Wydawnictwa AGH, 2005) Gumuła, Stanisław; Pytel, Sławomir; Słaboński, Paweł; Pytel, Krzysztof
The constructional solutions of new types of aerodynamic flat surfaces were introduced in publication. It was accomplished according to conception of Polish aerodynamic and aviator Witold Kasprzyk (international name of this plane is the Kasper Wings). Next units of publication contains the results of investigations on aerodynamic profiles of W. Kasprzyk wings then it labels as well as the moments circulating, bearing strengths, dependences of strengths resistance and angle the attack of stream of air on studied flat surface from the speed of air the regard. The scores of audits madę up to ąualification the basis of coefficients of resistance, the coefficients of bearing strength, coefficients of circulating moment as well as lift/drag ratio aerodynamic. It audits were conducted was on model placed in measuring space of aerodynamic tunnel with closed circulation of air pieces and closed me-asuring space. The studied flat surfaces be fastened to the deformeter, three components aerodynamic pair of scales. The scores of audits were introduced in graphic figurę. The results of audits can find first of all use near projecting wind power turbinę, especially these which have the perpendicular axises of turn as well as near pro-jecting the blades of fluid flow machinę engines.
Podobieństwa i różnice w zakresie struktury geometrycznej sekcji obudów ścianowych
(Wydawnictwa AGH, 2005) Losiak, Stanisław; Ptak, Jan; Blaschke, Janusz
In the paper a scheme of the geometrical structure, combined for three types of lemniscate wali support units and schemes of complementary units for correction of stretching and withdrawing of support have been presented. The principles of mathematical description for these units have been given. It has been demonstrated that in the basie scope the units may be presented by one description and in the scope of correction the units may be described by separate relations. The geometrical-kinematics characteristies of units have been presented which concerns their essential features, prepared on the basis of mathematical descriptions.