Wyniki wyszukiwania - Biblioteka Nauki

1

Stochastic eigenvalue problems of linear continuum

100%

Dupal J.

|

tom 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.

2

Acceleration generating corresponding to the proposed response spectra

100%

Dupal J.

|

tom 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.

3

Estimation of the critical velocities of the rotor systems containing random parameters

100%

Dupal J.

|

tom 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.

4

Reduction of continuous system of railway vehicle bogie to multibody one with low number DOF

100%

Dupal J.

|

2005

|

tom 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.

5

A periodic solution of the non-linear vibration of the car gear-box inner components

63%

Dupal J. , Kuruc T.

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tom 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.

6

Primary circuit vibration of VVER 440 reactor

63%

Zeman V. , Dupal J.

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tom 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.