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  1. 47 Scientific Letters of Rzeszow University of Technology. Mechanics
  2. 47 Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
  3. 7 Zeszyty Naukowe Politechniki Częstochowskiej. Budownictwo
  4. 2 Biuletyn Wojskowej Akademii Technicznej
  5. 2 Bulletin of the Military University of Technology
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  1. 1 2012
  2. 2 2011
  3. 47 2008
  4. 1 2007
  5. 2 2005
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  1. 5 Hendel J.
  2. 4 Tomski L.
  3. 4 Ziemiański L.
  4. 3 Szmidla J.
  5. 2 Bryja D.
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1
Content available remote Ocena stanu konstrukcji belkowych na podstawie zmiany parametrów modalnych wywołanych dodatkową masą
100%
Borowiec A. , Ziemiański L.
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
|
2008
|
tom z. 74 [258]
9-16
EN
This paper presents the application of the nondestructive damage identification method using an additional parameter introduced to the structure. In this method the damage is identified on the basis of the variations of dynamie parameters without knowledge of the initial values of undamaged structures. In the presented numerical examples, method are applied for the analysis of the dynamic response of cantilever beam for identification position of damage and the extent of damage. The assessment of the state of a structure relies on the comparison of the structure eigen-frequencies obtained from the systems with additional masses placed in different nodes.
2
Content available remote Zmienność parametrów modalnych w zależności od charakteru zniszczenia elementów belkowych
100%
Buda-Ożóg L. , Łakota W.
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
|
2008
|
tom z. 74 [258]
25-32
EN
The paper discusses methods of diagnosing the technical condition of reinforced concrete beams, based on the change in dynamic characteristics. The objects of research were reinforced concrete (RC) beams. Testing of RC beams included both static and dynamic tests. A series of step loaded static tests was aimed to produce successive damage to the beams. After each load step (at the moment of displacement and strain stabilization), dynamic testing followed. On the basis of the obtained results from different beams (different distances between supports), an effort was made to correlate the data concerning the damage of the tested beams with the changes of the modal parameters.
3
Content available remote Współczynnik dynamiczny dla szkieletu gruntu w modelu dwufazowym
100%
Wrana B. , Świegoda J.
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
|
2008
|
tom z. 74 [258]
411-419
EN
This paper deals with a description of the behavior of the two-phase soil layer (column) under periodic load. The soil layer (column) is fully saturated with single pore fluid and treated by the methods of continuum mechanics. Description of motion and deformation of soil is introduced as a system of equations consisting of governing dynamic consolidation equations based on Biot theory, selected constitutive and kinematic relations for small strains and rotation. The solution and results of simple one dimensional numerical analysis of the fully saturated layer under cyclic load are included. Also the so-called dynamic coefficient which shows amplification or attenuation of dynamic response is considered.
4
Content available remote Giętno-skrętne drgania budowli wysokich
100%
Labocha S.
Zeszyty Naukowe Politechniki Częstochowskiej. Budownictwo
|
2002
|
tom Z. 9 (154)
25-32
5
Content available Analiza numeryczna drgań własnych samolotu z niesymetrycznym płatem nośnym
84%
Błaszczyk J.
|
|
tom Vol. 60, nr 1
271-288
PL
Przedstawiono analizę numeryczną widma drgań niesymetrycznego samolotu wynikającego z urwania segmentu konsoli lewego skrzydła. Zastosowano dynamiczne modele samolotu z poprzednich prac [10, 5, 7, 8]. Do analizy numerycznej wykorzystano dane współczesnego, szkolno-bojowego samolotu z napędem odrzutowym [21], zbudowanego w konwencjonalnym układzie aerodynamicznym.
EN
In the paper, the numerical analysis of an aircraft self vibration with the non symmetrical wing was presented. The non symmetrical structure of the wing is a result of damage made to the left wing segment. For the need of the analysis, the dynamical models of the aircraft considered in the previous works were used [10, 5, 7, 8]. A modern training-jet with conventional lay-out was investigated and evaluated by the author [21].
6
Content available Analiza numeryczna drgań własnych samolotu z nieciągłościami struktury środkowej części kadłuba
84%
Błaszczyk J.
|
|
tom Vol. 56, nr 1
287-301
PL
W artykule przedstawiono analizę numeryczną wpływu nieciągłości struktury siłowej środkowej części kadłuba na widmo drgań własnych samolotu. Zastosowano dynamiczne modele samolotu z poprzednich prac [3, 7]. Do analizy numerycznej wykorzystano dane współczesnego szkolno-bojowego samolotu z napędem odrzutowym [13], zbudowanego w konwencjonalnym układzie aerodynamicznym.
EN
In the paper, an impact of discontinuous structure of the middle part of the aircraft fuselage on its vibration spectrum was presented. For the need of the numerical analysis, the dynamical models were used from the previous works [3, 7]. In the work, a modern jet trainer designed in the conventional aerodynamic lay-out was investigated [13].
7
Content available remote Symulacja pętli histerezy betonu z wykorzystaniem sztucznych sieci neuronowych i metod Bayesowskich
84%
Krok A.
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
|
2008
|
tom z. 74 [258]
165-173
EN
Feed-forward layered Artificial Neural Networks (ANN) learnt by means the evidence procedure for Bayesian technique are used for simulation and prediction of hysteresis loops. Concrete hysteresis loops obtained by cyclic loading are considered. ANN were learned and tested on the experimental data. The prediction of the stress - strain relation was made for the last part of the experiment, basing on its previous stage.
8
Content available remote A numerical model formulation for the underground railway vibration prediction
84%
Kogut J. , Ciurej H.
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
|
2008
|
tom z. 74 [258]
143-154
EN
This paper discusses a theoretical-numerical model formulation for the prediction of vibrations from underground railway traffic. The model takes into consideration transfer junctions between the track lying in the underground tunnel and a free field. The rolling stock can be modeled as a multi-body vehicle chain. The dynamic axle loads due to the rails and wheels irregularities may be estimated. In the model a wheel-rail single point Hertzian contact is assumed. As for the dynamic track and tunnel compliance the transfer functions can be computed and/or measured. The entire model can be validated by means of vibration "in-situ" measurements.
9
Content available remote Wybrane problemy konstrukcyjne i badawcze cylindrycznego sprzęgła elektrore-ologicznego
84%
Skup Z.
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
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2008
|
tom z. 74 [258]
299-308
EN
The article describes basic tests of the following: power consumption (supply voltage 1-6 kV, current intensity 5-25 A/cm2, power supply 10-100 W), temperature increases as well as technical solutions and construction of the tested electrorheological clutch. Two types of fluid were described: one-phase liquid in the form of "liquid crystals", which does not undergo sedimentation or coagulation, and two-phase liquid in the form of "suspension" containing stabilizing agents. Factors determining Theological parameters of the prototype ER clutch were discussed. The article ends with conclusions and a summary.
10
Content available remote Analiza sił oddziaływania w układzie operator - ręczna szlifierka
84%
Piotrowski S. , Snamina J.
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
|
2008
|
tom z. 74 [258]
283-290
EN
The paper presents the analysis of dynamic interaction between a hand-arm and a hand-held grinder. A model of the system has been introduced that consists of a discrete model of a grinder and a simply biodynamic model of the human hand-arm. Basic equations describing the motion of the system were introduced. The random vibration (PSD) analysis was done. Some general conclusions were presented and several recommendations on how the vibration level could be reduced.
11
Content available remote Wykrywanie uszkodzeń konstrukcji z wykorzystaniem fal sprężystych oraz sztucznych sieci neuronowych
84%
Nazarko P. , Ziemiański L.
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
|
2008
|
tom z. 74 [258]
271-282
EN
Examination of structures integrity and failures detection are nowadays of great interest for both civil infrastructure and industry systems. This paper presents Structural Health Monitoring (SHM) technique that was tested on several laboratory models and utilizes elastic wave propagation phenomenon. Furthermore, it describes signals feature extraction procedure by using Principal Component Analysis (PCA). Artificial Neural Networks (ANNs) and statistical learning theory are used to determine and classify structure's damages. The results show that data reduction using PCA, followed by implementation of ANNs patterns recognition, provide a good indication of failure occurrence and they may be used for SHM.
12
Content available remote Stateczność i drgania swobodne siłownika hydraulicznego sprężyście zamocowanego
84%
Tomski L. , Uzny S.
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
|
2008
|
tom z. 74 [258]
381-392
EN
Theoretical, numerical and experimental research concerning of stability and free vibrations of hydraulic cylinder is presented in the paper. Considered hydraulic cylinder was fixed elastically and subjected to Euler's load. The boundary problem was formulated on the basis of Hamilton's principle. Mathematical model was confirmed by experimental research.
13
Content available remote Generator zadanej trajektorii ruchu obiektu dynamicznego
84%
Żylski W. , Gierlak P.
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
|
2008
|
tom z. 74 [258]
421-432
EN
The fundamental problem of robots' dynamics and control is the computation of desired trajectoty for dynamical object. In order to do that, inverse kinematic problem should be solved. A singular inverse kinematics problem for the SCORBOT manipulator has been solved using the model with variable structure. Feedforward multilayered neural networks and genetic algorithm has been utilized in this model The backpropagation algorithm has been utilized for training network. The neural networks have been used outside the singularity. In the singularity the genetic algorithm has been used for computation of the angular velocities. Results of the simulation have been presented.
14
Content available remote Problemy dynamiki strukturalnej mikroukładów
84%
Uhl T.
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
|
2008
|
tom z. 74 [258]
433-440
EN
The paper deals with some problems of micro-electromechanical system design and testing. Design process of mechanical parts of this micro-systems is discussed. The role of modeling and simulation study for design of micro - systems including structural dynamic problems is presented. Uncertainty of the MEMS structures are common in typical design due to technological manufacturing process which is very little controllable. The influence of system parameters uncertainty on dynamic features variability is discuss. Case study of micro-comb resonator is considered.
15
Content available remote Drgania i stateczność szczególnego układu smukłego poddanego obciążeniu siłą skierowaną do bieguna dodatniego
84%
Tomski L. , Podgórska-Brzdękiewicz I. , Szmidla J.
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
|
2008
|
tom z. 74 [258]
357-368
EN
This paper concerns the issue of stability and free vibrations of slender system loaded by the force directed towards the positive pole. Two rod system connected with tube element is tested. The rope system is element of forcing head. It enables the application of the given direction and the point of application of external force towards considered column. The physical model of tested system and theoretical considerations related to determination of boundary conditions by using the method of mechanical energy variation are shown in this paper. Constructional scheme of the loading and receiving head is presented. Values of the critical force and the course of natural frequency in relation to the external load for given geometry and physical constants of the system are determined. The results of theoretical and numerical research are experimentally verified on the stand.
16
Content available remote Stateczność i drgania swobodne dyskretnej ramy typu: słup - rygiel obciążonej siłą śledzącą skierowaną do bieguna dodatniego
84%
Tomski L. , Podgórska-Brzdękiewicz I.
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
|
2008
|
tom z. 74 [258]
345-356
EN
This paper concerns the issue of stability and free vibrations of discrete, two-part planar frame, built of frame bolt and frame column. Frame column is loaded by the follower force directed towards the positive pole. The loading and receiving head are built of the circular elements. Theoretical considerations are made concerning analysis of the system geometry and determination of relations for the potential energy and kinetic energy of the considered system. Adequate relationships describing stability of the considered frame are obtained taking into account energetic method or vibration method. An influence of geometrical parameters of loading head and rigidity of rotational springs modeling the finite stiffness of structural constraints on the critical load is analyzed. The courses of natural vibration frequencies in relation to the external load are determined.
17
Content available remote Weryfikacja obliczeniowa wzorów empirycznych dla obliczania podstawowych okresów drgań pewnego typu budynków ścianowych
84%
Wdowicki J. , Filipowicz A. , Wdowicka E.
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
|
2008
|
tom z. 74 [258]
393-402
EN
The paper is concerned with the prediction of fundamental vibration periods of multistorey shear wall buildings. The determination of natural frequencies is the key issue in designing of tall buildings. The calculation of natural frequencies and mode shapes is the first step in evaluation of the dynamic response of the structure by the modal superposition technique. The values of natural frequencies are also required in the determination of equivalent static loadings due to wind actions. The comparison of estimation of fundamental vibration period from the proposed in the literature formulae has been the main aim of the present paper. The empirical equations presented in the papers [1-4] have been considered. Computations have been carried out by using the following specialised computer programs for shear wall structures: BW for Windows [5, 6] and ETABS [7]. The paper has provided the comparison of fundamental periods of shear wall dominant buildings constructed by using tunnel form techniques, the models of which were discussed in the papers [1, 2, 8]. For more than 15-storey high buildings the results of computations using the continuous model of shear wall structure agree well with finite element analysis results.
18
Content available remote Bayesowskie sieci neuronowe w analizie problemów regresji
84%
Waszczyszyn Z.
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
|
2008
|
tom z. 74 [258]
441-455
EN
The lecture entitled "Bayesian Neural Networks in the Analysis of Regression Problems" deals with basics of the Bayesian inference (BI) and its various methods and relations to the Standard Neural Networks (SNNs). In subsequent Sections the following problems are discussed: 1) Bayesian Neural Networks (BNNs) as a fusing of SNN and BI; 2) The regression and Feed-forward Layered Neural Network (FLNN); 3) Principles of BI; 4) Maximum Likelihood (ML) and Maximum APosterior (MAP) methods; 5) Criterion of Maximum EVidence (MEV), 6)Types of BNNs. Special attention is focused on the application of MAP for the controlling the over-fitting of the neural approximation. The MEV is also explored for the design of deterministic networks FLNN/MAP. The more extended application of BI enables to formulate a semi-probabilistic simple network S-BNN and a truly probabilistic Bayesian network T-BNN. A numerical efficiency of the Bayesian methods and networks is discussed in paper [1] presented at the XIII Symposium DYNKON2008.
19
Content available remote Drgania własne chłodni powłokowej
84%
Hendel J. , Borowik M. , Koza P.
Zeszyty Naukowe Politechniki Częstochowskiej. Budownictwo
|
2005
|
tom Z. 12 (160)
19-40
20
Content available remote Drgania własne jednotorowego stalowego wiaduktu kolejowego
84%
Hendel J. , Kaczorowski S.
Zeszyty Naukowe Politechniki Częstochowskiej. Budownictwo
|
2005
|
tom Z. 12 (160)
41-52
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