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1
Content available remote The realization of modal superposition method in shell dynamic problems with constructive heterogeneites
100%
Zarutsky V. , Lerman L.
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
|
1999
|
tom z. 52 [174]
127-132
EN
In this paper the practical reaIization of the modal superposition method conformably to linked systems of think - walled elements were considered. The solutions of non-stationary problems for shells with constructive heterogeneites in form of local support elements were received and two possibilities of this approach have been realized. First one is connected with using modal superposition of separate elements and finding of the dynamical interaction stresses on the base of kinematic compatibility conditions. Such a possibility was realized on example of plates (shallow shells) with elastic interior rod supports. Seeond way is based on series' expansions for the stationary states of the system as a whole. In this case the dynamic deformation problem of spherical caps (ring plates) with a coaxial cylindrical shell a support element was solved. For both problems the results af the calculations done are presented.
2
Content available remote Identyfikacja własności dynamicznych modelu budynku na stole wstrząsowym
100%
Zembaty Z. , Kowalski M.
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
|
1999
|
tom z. 52 [174]
133-138
EN
The paper presents selected results of dynamic identification of a model of brick masonry building subjected to a series of tests on shaking table. Various identification methods have been applied: peak picking, animations of harmonic motion in resonance, half power bandwidth method, circle fit technique and finally least squares method for time history records in frequency domain. As a result natural frequencies, damping ratios, mode shapes and effective modal participation factors were estimated. The dynamic behaviour of the analysed model has been investigated and various results of identifications compared and discussed in detail.
3
Content available remote Model tłumienia wewnętrznego przewodów elektroenergetycznych
100%
Snamina J.
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
|
1999
|
tom z. 52 [174]
97-102
EN
The aim of the present paper is to discuss the problem of internal mechanical damping of overhead cables. The mathematical model of this phenomenon is presented. The influence of damping parameter on energy dissipation and amplitude is analyzed. Selected resuIts of experiments are presented.
4
Content available remote Dynamiczny model lepkoplastycznej powłoki walcowej
100%
Sławianowska A.
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
|
1999
|
tom z. 52 [174]
91-96
EN
The paper is concerned with the dynamics of viscoplastic cylindrical shells. The considerations are restricted to the simply supported shells subjected to a rotationally symmetric uniform internal pressure pulse. The application of the linearized flow rule leads to a closed form solution. A graphical representation of the solution is also presented.
5
Content available remote Analiza niezawodności płyty poddanej działaniu dynamicznego obciążenia okresowo - stacjonarnego
100%
Bryja D. , Mironowicz W.
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
|
1999
|
tom z. 52 [174]
29-34
EN
Random vibrations of the system consisting of the rectangular, isotropic, thin plate and the rigid block supported on it viscoelastically is considered in the paper. The system is subjected to the periodic series of random, short-duration shocks, as it often occurs in dynamic action of machines. The solutions in the form of expected value and covariance of the displacement and its speed at the optional point of the system are obtained. The results are applied to simplified, practically useful analysis of the first crossing problem formulated for the cyclostationary load series. Examples of numerical analysis are presented and discussed.
6
Content available remote Wprowadzenie do analizy dynamicznej płyty pływającej pod obciążeniem ruchomym
100%
Ataman M. , Szcześniak W.
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
|
1999
|
tom z. 52 [174]
19-28
EN
In the paper non-homogeneous models of floating ice covers subjected to moving loads are presented. The models presume that the ice sheet may be represented as a thin, elastic, infinite plate on a fluid foundation. The modified flexural rigidity is used in the plate equations. The underlying water is modelled as a massless Winkler foundation or as an inviscid and incompressible fluid in irrotational flow described by a velocity potential. In the both cases critical velocities are determined. For the plate on the Winkler foundation a phase velocity in function of wave number k is determined also.
7
Content available Zastosowanie rachunku operatorów Mikusińskiego w pewnych zagadnieniach dynamiki konstrukcji
100%
Poński M.
Zeszyty Naukowe Politechniki Częstochowskiej. Budownictwo
|
2012
|
tom Z. 18 (168)
211--217
PL
W pracy przedstawiono zastosowanie rachunku operatorów Mikusińskiego do podstawowych zagadnień dynamiki konstrukcji budowlanych na przykładzie prostego modelu obliczeniowego drgań układu o jednym stopniu swobody. Metoda ta, nie oparta na metodach transformacji całkowych, jest efektywnym narzędziem do rozwiązywania liniowych równań różniczkowych o współczynnikach stałych.
EN
This article describes the use of Mikusiński operators method on basis of dynamics of structures, as an example of a simple computational model of vibration system with one degree of freedom. This method, not based on the methods of integral transform, is an effective tool for solving differential equations with constant coefficients.
8
Content available Zróżnicowanie województw Polski pod względem struktury obszarowej gospodarstw ekologicznych
100%
Luty L.
Metody Ilościowe w Badaniach Ekonomicznych
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2012
|
tom 13
|
nr 3
149-158
PL
Rolnictwo ekologiczne jest systemem gospodarowania wykorzystującym naturalne procesy zachodzące w gospodarstwie rolnym. Celem rolnictwa ekologicznego jest produkcja żywności o wysokiej jakości zdrowotnej oraz utrzymanie obszarów środowiska przyrodniczego w naturalnym stanie. Dynamiczny rozwój rolnictwa ekologicznego w Polsce obserwujemy od roku 2004. Wprowadzono wówczas dotacje do ekologicznej produkcji rolnej dla gospodarstw posiadających certyfikat zgodności i będących w trakcie przestawiania. Celem opracowania będzie przedstawienie statystycznej analizy struktury obszarowej gospodarstw ekologicznych w województwach Polski w latach 2007-2010. Do podziału zbioru obiektów na podzbiory, które charakteryzuje relatywnie niski stopień zróżnicowań badanej struktury zostanie wykorzystana metoda eliminacji wektorów. Łańcuchowe miary zmienności struktur pozwolą ocenić przebieg zmian strukturalnych.
EN
Organic farming is a system of farming that uses natural processes used in the farm. The aim of organic farming is the production of food of healthy high quality and the keeping of environmental areas in the natural state. Dynamic development of organic farming in Poland has been observed since 2004. At that time there were introduced the subsidies to organic agricultural production for holdings with the certificate of conformity and in the course of transformation. Purpose of this paper is to present a statistical analysis of the structure of the area of the organic farms in Polish voivodeships in the years 2007-2010. To divide the set of objects into subsets, which is characterised by a relatively low degree of variations of the tested structure is used the method of elimination of vectors. Chain measure of variation of structures will enable to evaluate the course of structural changes.
9
Content available ZMIANY STRUKTURY OBSZAROWEJ GOSPODARSTW EKOLOGICZNYCH W POLSCE W LATACH 2004-2012
100%
Luty L.
Metody Ilościowe w Badaniach Ekonomicznych
|
2014
|
tom 15
|
nr 3
208-218
PL
Celem opracowania będzie przedstawienie zmian struktury obszarowej gospodarstw ekologicznych w Polsce, w latach 2004-2012. Wykorzystane mierniki taksonomiczne, pozwolą ocenić stopień i kierunek zmian strukturalnych. Łańcuchowe miary zmienności struktur pozwolą ocenić także przebieg zmian strukturalnych dla województw Polski. Dla analizowanych addytywnych struktur oszacowane zostaną współczynniki koncentracji w układzie rodzajowym i przestrzennym. Ponadto, wyznaczone zostaną prognozy struktury obszarowej gospodarstw ekologicznych dla Polski na trzy kolejne lata.
EN
Organic farming production methods are part of the concept of sustainable development, therefore it becomes important to study the level of organic farming, its development, regional diversification and the trend and rate of change. The aim of this paper was to present changes to the structure of the area of organic farms in Poland in the years 2004-2012. Used taxonomic meters, allowed to assess the degree and direction of structural changes in the Polish voivodeships. For analyzed additive structures concentration coefficients were estimated. In addition, there is forecast for the structure of area for organic farms for the next three years in Poland.
10
Content available remote Przedziałowe metody całkowania równań dynamiki konstrukcji
84%
Pownuk A.
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
|
1999
|
tom z. 52 [174]
77-84
EN
In this paper the interval methods for validated solution of ordinary differential equation of dynamics of structures are presented. The interval Euler's method for solving system of ordinary differential equations with automatic determination of guaranteed estimation and high order Taylor series method are described. Using these methods two problems of free vibration are solved.
11
Content available remote Algorytmy sumowania w metodzie spektrum odpowiedzi i ich wpływ na obliczaną odpowiedź budynku wysokiego
84%
Wdowicka E. , Wdowicki J.
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
|
1999
|
tom z. 52 [174]
119-126
EN
An evaluation is presented of some of the modal maxima superposition rules, widely used to estimate the response of multistorey buildings, subjected to earthquake excitations: (1) the square root of the sum of the squares (SRSS) method; (2) the double sum combination (DSC) method; (3) the complete quadratic combination (CQC) method. The SRSS method provides good peak response estimates for the regular building, but gives the poor results for irregular building with the mass offset from the stiffuess centre, in which arise modes with closely spaced periods. It is conclude, that the DSC and CQC methods provide good response estimates of equivalent accuracy, for both the regular and irregular building models.
12
Content available remote Odpowiedź dynamiczna osłoniętej podziemnej ściany podporowej na obciążenia parasejsmiczne
84%
Ciesielski R. , Kwiecień A.
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
|
1999
|
tom z. 52 [174]
35-46
EN
In the paper, the action of paraseismic vibration on the underground garage wall has been presented. This wall had been separated from the surface impulsive excitation by another retaining wall. Results of the investigations, in form of diagrams of the ground and walls vibration accelerations, were prepared and presented. The influence of the retaining wall on decreasing of acceleration amplitudes of the underground wall was observed. The results obtained from the research were compared to the results calculated according to the absorption theory in the ground and generally they were close.
13
Content available remote Stateczność dynamiczna kolumn dywergencyjnych pseudoflaterowych
84%
Tomski L. , Sochacki W.
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
|
1999
|
tom z. 52 [174]
111-118
EN
The problem of the dynamic stability of columns under generalised load as well as loaded by a followerforce passing, through a fixed point bas been considered. Geometrical and physical properties of columns have been assumed in such a way that the columns are of the divergence pseudoflutter type. The change of the natural frequency versus the load as well as the influence of the varied part of the load on the dynamic stability has been presented.
14
Content available remote Niepryzmatyczny prętowy element skończony - zagadnienia dynamiczne
84%
Ruta P.
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
|
1999
|
tom z. 52 [174]
85-90
EN
The dynamic stiffness matrix and mass matrix have been estimated for finite bar element lying on non-homogenous elastic foundation. Czebyszew's series were used for shape function's approximation. Analytic formulas for the matrixes's elements was obtained. The finite element was used to solve eigenvalue problem for simple-supported and cantilever beam. The results were compared with other author's results.
15
Content available remote Redukcja drgań rezonansowych stalowych fundamentów ramowych pod maszyny obrotowe
84%
Grosel J. , Klasztorny M.
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
|
1999
|
tom z. 52 [174]
57-64
EN
A matrix dynamic equation of motion of a steel frame foundation for rotary machines, equipped with passive dynamic absorbers, is formulated. Transoms and columns of the foundation are made as thin walled bars of an open contour. The machines are treated as vibroisolated rigid bodies. The spatial thin walled frame is discretised with FEM. The system satisfies some orthogonality conditions, used in the assembly process. The absorbers are optimally localised as well as optimally tuned with respect to selected modal systems of the original structure and are applied for reducing steady-state forced vibrations of the light damped foundation in the resonant zones. A computer algorithm and programme are written, useful for dynamic analysis of engineering structures undertaken. Dynamic analysis of a realistic foundation for a turboset is performed.
16
Content available remote Wrażliwość projektowania drgań mostu żelbetowego poddanego działaniu pojazdu
84%
Podwórna M. , Śniady P.
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
|
1999
|
tom z. 52 [174]
71-76
EN
The sensitivity analysis of the vibrations of a single span bridge due to moving load with constant velocity is considered. The vehicle is modelled as a linear discrete (four degrees of freedom) mass-spring-damper system. The effect of the quantity b (bottom width of the bridge beam) on the beam's deflection is showed.
17
Content available remote Drgania pasma płytowego o zmiennej grubości
84%
Szcześniak W.
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
|
1999
|
tom z. 52 [174]
103-110
EN
Forced vibrations of variable thickness plate strip are discussed. The massless loads move at a constant velocity. Numerical examples are presented.
18
Content available remote Drgania odciągów masztów i rozwiązania techniczne prowadzące do ich redukcji
84%
Kawecki J.
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
|
1999
|
tom z. 52 [174]
65-70
EN
The general problem of the guy - cables vibrations in tall guyed masts is considered. Two types of damping systems were presented. One of them is used in situations where guy galloping occurs. The second is used for high - frequency aeolian vibration.
19
Content available remote Odpowiedź dynamiczna budynków leżących w pobliżu metra warszawskiego (badania in situ)
84%
Ciesielski R. , Stypuła K.
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
|
1999
|
tom z. 52 [174]
47-56
EN
Dynamic response of buildings situated close to Warsaw underground metro line were presented on the basis of "in situ" measurements, which were performed on first metro line along Marszałkowska street, downtown Warsaw. Results of investigations are used in diagnoses and plans for further construction works.
20
Content available remote Zastosowanie sieci neuronowej i filtru Kalmana do symulacji spektrów odpowiedzi budynków poddanych działaniu wymuszeń parasejsmicznych
84%
Krok A. , Waszczyszyn Z.
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
|
2005
|
tom z. 65 [222]
219-226
EN
Decoupled Extended Kalman Filter (DEKF) algorithm was used for the training of Feed-forward Layer Neural Network (FLNN). Data taken from [1] correspond to Displacement Response Spectra (DRS) computed on the base of vibration records measured on the ground level for paraseismic excitation (inputs to FLNN) and on the fourth floor of monitored buildings (outputs of FLNN). It was proved that the application of DEKF gives much more accurate predictions of DRS than standard NN discussed in [1].
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