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1
Acceleration generating corresponding to the proposed response spectra
Dupal J.
Modelowanie Inżynierskie
|
2012
|
T. 14, nr 45
39--44
EN
Nuclear devices are checked also from the seismic safety point of view. The response spectra method is one of the most important approaches to obtain an upper estimation of some output variables like displacements, velocities, accelerations, stresses etc. The proposed response spectra of the base especially accelerations serves as an input for extreme estimations of mentioned output quantities depending on frequency [1]. The alternative approach for functionality assessment can be used the base acceleration as an input for time integration of the mathematical model and the output quantities can be obtained in the direct integration way of the model. The main requirement on the input acceleration is posed on the desired response spectrum satisfaction. The paper deals with an approach to generation of the base acceleration in such a way to be satisfied the properties of the proposed prescribed response spectrum of the acceleration.
CS
Bezpečnost jaderných zařízení je kontrolována mimo jiné také ze seizmického hlediska. Metoda spekter odezvy patří mezi nejdůležitější metody pro určení horního odhadu výstupních veličin, za které považujeme posuvy, rychlosti, zrychlení, napětí atd. Presentovaný přístup pro posouzení funkčnosti využívá zrychlení základu odpovídající návrhovému spektru odezvy jako kinematické buzení matematického modelu a výstupní veličiny lze získat přímou integrací.
2
Parametric vibration of the gear mesh
Dupal J., Zajicek M.
Modelling and Optimization of Physical Systems
|
2011
|
z. 10
15--20
EN
The paper is focused on the analytical solution to periodical vibration of gear mesh containing the time dependent stiffness. Solution of such mathematical models can be used for the response computation of various drive mechanisms, gearbox vibration, in rotor dynamics etc. The model behaviour is described by means of the Fredholm's integral equation with degenerated kernel and a periodical Green's function is used for the solution. The application of the presented methodology was performed on the spur gear mesh of the second gear of the VW concern gearbox MQ 200. The result correctness is validated by means of Runge-Kutta integration method.
3
Interaction of thin walled structures with piezoelectric patches
Dupal J.
Modelling and Optimization of Physical Systems
|
2010
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z. 9
15--20
EN
The paper deals with analytical modelling of plate structures excited by piezoelectric (PE) patches for comparison with corresponding FE solution. The complete equation of motion of the plate with PE was developed and the solution das not take into account stiffness of the patches. The finite element solution which takes into account the elastic and inertial properties of patches extends scope of this paper.
CS
Clanek uvadi analyticke modelovani deskovych konstrukci buzenych piezoelektrickymi zaplatami pro srovnani odpovidajicim resenim pomoci MKP. Byla odvozena kompletni pohybova rovnice desky s piezo, jejiz reseni nebere v uvahu tuhost zaplat. Reseni pomoci MKP, ktere respektuje elasticke i setrvacne vlastnosti zaplat presahuje ramec tohoto prispevku.
4
Stochastic eigenvalue problems of linear continuum
Dupal J.
Modelling and Optimization of Physical Systems
|
2009
|
z. 8
29--36
EN
The paper deals with an approach to the Solution of the eigenvalue problem of the linear continuous vibrating system described by some parameters having random character. Our attention will be payed to continua whose behaviour can be characterized by seif adjoint Operators. Result of the calculation will be expected value and dispersion of eigenvalues. Knowing the Statistical characteristics of the input random parameters and applying the six sigma criterion we can determine maximal and minimal values of eigenvalues in the probability sense.
5
Optimization of plate vibro-isolation from the acoustic point of view
Dupal J.
Modelling and Optimization of Physical Systems
|
2008
|
z. 7
19--22
EN
The paper deals with a methodology of vibro-isolating foam distribution under plate modeled by FEM. A special finite element with viscous-elastic foundation containing a cavity was developed. The characteristic proportions of the cavities are used as the optimization parameters for minimization of surface velocities of the plate. The weighted sum of velocity amplitudes over the frequency broad band can be taken into account as a criterial function of optimization process.
6
The transient response of vibrating systems containing random parameters
Dupal J.
Modelling and Optimization of Physical Systems
|
2007
|
z. 6
37--40
EN
The paper deals with a methodology of statistical parameter (mean, covariance and standard deviation) determination of n-DOF linear vibrating system displacements in transient vibration. It is supposed a proportional damping which means that the damping matrix is linear combination of the mass and stiffness matrices. The perturbation approach [1] is applied to the parameter calculation and estimation of the upper and lower limits of displacements in the probability sense.
7
Modelling of pipeline systems conveying fluid under large displacements and rotations
Dupal J.
Zeszyty Naukowe Katedry Mechaniki Stosowanej / Politechnika Śląska
|
2006
|
z. 31
7-10
EN
The paper deals with modelling approach to the pipeline vibration under flowing fluid influence respecting large displacements and rotations but smali strains and thus the validity of Hoocke's law is supposed. A corotational formula is used for deriving of equation of motion and individual element matrices expressing inner and inertia forces. In case of straight elements a Green's strain tensor relative to corotational coordinate system is used. This tensor can not be replaced by Cauchy strain tensor inspite the deformation is smali because the Cauchy strain tensor is not able to respect the membrane deformation [1]. The second Piola-Kirchhof tensor is used as a measure of stress. The matrices corresponding to the inner and inertia forces are displacement and velocity dependent and for this reason the resulting equation of motion is geometrically nonlinear.
8
Reduction of continuous system of railway vehicle bogie to multibody one with low number DOF
Dupal J.
Zeszyty Naukowe Katedry Mechaniki Stosowanej / Politechnika Śląska
|
2005
|
z. 28
17-20
EN
Modelling huge system consisting of many subsystems and modelled by the professional software package it is useful to reduce degrees of freedom (DOF) of individual subsystem while the chosen eigenfrequencies and eigenvectors are preserved. It can be performed by means of modal condensation [1], [2] under the additional conditions. These conditions are posed on the total mass, moment of inertia and position of the gravity centre.
9
Estimation of the critical velocities of the rotor systems containing random parameters
Dupal J.
Zeszyty Naukowe Katedry Mechaniki Stosowanej / Politechnika Śląska
|
2004
|
z. 25
39-42
EN
The paper deals with an approach to statistic estimation of mean, standard deviation and variance of the rotor system critical velocities by means of perturbation method. The model of the rotor takes into account inner damping (Kelvin - Voigth material), rotary inertia and gyroscopic effect. The random parameters are geometrical and material parameters of the rotor system whose mean, variances and cross covariances are known as the inputs.
PL
W pracy przedstawiono metodę statystycznego oszacowania wartości średniej, odchylenia standardowego i wariancji prędkości krytycznych dla rozpatrywanych układów za pomocą metody zaburzeń. Prezentowany w artykule model wirnika uwzględnia wewnętrzne tłumienie, bezwładność wirnika i efekt żyroskopowy. Losowe parametry to parametry geometryczne i materiałowe układu wirnika, których wartości średnie, wariancje kowariancje wzajemne są znane.
10
Correction of the straight pipe finite element matrices caused by pressured flowing fluid
Dupal J.
Zeszyty Naukowe Katedry Mechaniki Stosowanej / Politechnika Śląska
|
2003
|
z. 22
23-26
EN
The paper deals with a correction of mass, stiffness and damping matrices of the straight pipeline finite element. The growing fluid flow velocity causes a decrease of eigenfrequencies. When some eigenfrequency achieves zero value the whole system is at the stability boundary. Crossing the corresponding velocity boundary a loss of stability occurs.
11
Primary circuit vibration of VVER 440 reactor
Zeman V., Dupal J.
Zeszyty Naukowe Katedry Mechaniki Stosowanej / Politechnika Śląska
|
2002
|
z. 19
179-182
EN
The modal synthesis method with reduction of the number of DOF is used for the vibration analysis of the nuclear power plant primary circuit. This one is excited by the pressure pulsation generated by main circulation pumps. The method is applied to the primary circuit of VVER 4401213 reactors with six coolant loops.
12
A periodic solution of the non-linear vibration of the car gear-box inner components
Dupal J., Kuruc T.
Zeszyty Naukowe Katedry Mechaniki Stosowanej / Politechnika Śląska
|
2002
|
z. 19
31-34
EN
The paper deals with an approach to solution of periodic motion of large nonlinear systems consisting of linear subsystems coupled by linear and nonlinear couplings. A shooting method [1] is used to looking for a periodic solution of these systems. This approach is applied to the inner components of car gear-boxes excited by kinematic transmission errors generated by gear-mesh. The nonlinearities caused by loss of force flow in gear-mesh are included.
13
FEM model of cracked rotor
Dupal J.
Zeszyty Naukowe Katedry Mechaniki Stosowanej / Politechnika Śląska
|
2001
|
z. 16
25-28
EN
The paper deals with a method of cracked rotor modelling with several cracks. It is assumed each crack to be placed in one finite element and position of crack is known. Moreover smali difference between uncracked and cracked deflection lines is supposed. The stiffness matrix of cracked element is dependent on displacements of nodes and thus strongly non-linear. For stability investigation a Floquet theory can be used.
PL
W pracy przedstawiono metodę modelowania pękniętego wirnika z kilkoma pęknięciami. Założono, że każde pęknięcie znajduje się w jednym elemencie skończonym i położenie pęknięcia jest znane. Ponadto założono niewielką różnicę pomiędzy linią odkształcenia z pęknięciem i bez pęknięcia. Macierz sztywności elementu pękniętego zależy od przemieszczenia węzłów i jest silnie nieliniowa. Do badania stabilności zastosowano teorię Floquet.
14
Tuning of the thin-walled beam structures
Dupal J.
Zeszyty Naukowe Katedry Mechaniki Stosowanej / Politechnika Śląska
|
2000
|
z. 12
13-16
EN
The paper deals with a way of spectral tuning of structures consisting . Of thin-walled beams cross-sections of which are assembled from open branches triangle and quadrangle closed chambers. The dynamic analysis is based on the Vlasov's and Umanski's theories. For solving of the equation of motion the fem is used. A succesive approximation method is used for the timing process.
PL
W pracy przedstawiono sposób dostrajania widmowego struktur składających się z cienkościennych prętów z gałęziami otwartymi oraz trójkątnymi i czworokątnymi zamkniętymi przestrzeniami. Analiza dynamiczna bazuje na teorii Własowa i Umanskiego. Równania ruchu rozwiązano metodą elementów skończonych. W procesie dostrajania zastosowano metodę kolejnych przybliżeń.
15
Pipe elbow modelling by means of FEM
Dupal J.
Zeszyty Naukowe Katedry Mechaniki Stosowanej / Politechnika Śląska
|
1999
|
z. 11
17-20
EN
The beam and elbow elements are most freąuently used for modelling of pipe systems. Parameters of those elements can be obtained from separated calculation using 3D FEM analysis and some of physical condensation method. The contribution is aimed to show how the mathematical model of pipe system is developed.
PL
Najczęściej do modelowania układów rurowych stosuje się elementy belkowe i kolankowe, parametry takich elementów można wyznaczyć za pomocą osobnych obliczeń z wykorzystaniem przestrzennej analizy MES i metod kondensacji fizycznej. Celem tego artykułu jest przedstawienie sposobu budowy modelu matematycznego układu rurowego.
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