Contents of Journal of Mechanical Engineering 56, 5 (2005)

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BOUAZARA, M.: Optimization of the suspension parameters and tire
forces analysis on a vehicle model using an analytical approach         257

PŮST, L., KOZÁNEK, J.:  Nonlinear vibrations of rotor supported
on passive magnetic bearings                                            273

PING, Y.: Numerical characteristics analysis of multi-medium
coupling vibration isolator                                             289

KIZILOVA, N. N., EGOROVA, E. S.: Modelling of laminated growing
biological materials                                                    306

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Abstracts

Optimization of the suspension parameters and tire forces analysis on a vehicle model using an analytical approach

MOHAMED BOUAZARA

An analytical approach is presented to combine a tire forces analysis and an optimal suspension parameter for a vehicle model. The vehicle suspension is modelled by a linear spring and dashpot elements. With such approach, the equations of motion are expressed as a linear system. Using 2-D vehicle model, a method for the performance estimation of vehicle suspension system is presented. In this method, the variables of performance estimation, frequency response, \$rms\$ response and weighting factors are considered. Simulation results are presented and design data are suggested for optimal design parameter estimation value, which maximizes the performance criteria of the given suspension system.

Nonlinear vibrations of rotor supported on passive magnetic bearings

LADISLAV PŮST, JAN KOZÁNEK

The main aim of this study is to gain the basic knowledge about the dynamic properties of a rigid rotor supported on two passive magnetic bearings. The attention is given to the motion with impacts in retainer bearings designed as rolling bearings. These properties are investigated by means of numerical solution of mathematical model of the prototype developed in the Institute of Thermomechanics AS CR.

Numerical characteristics analysis of multi-medium coupling vibration isolator

YANG PING

To understand mathematical characteristics of the multi-medium coupling vibration isolator, a mathematical model of the multi-medium vibration isolator is presented in this paper. The model can simulate characteristics of the actual vibration isolator device. In order to analyse numerical characteristics of the multi-medium coupling vibration system, the solution was implemented by introducing harmonic transform method and Fourier transform method. Some numerical characteristics of the system are presented with varying parameters. The parameters of optimal design for the vibration isolator are derived.

Modelling of laminated growing biological materials

NATALYA N. KIZILOVA, ELENA S. EGOROVA

The continual model of the multilayered plate from a growing biological material is presented. Introducing the Airy's stress function the problem is reduced to differential equation of the fourth order. Solution of the problem is obtained for the two-layered plate with a rectangle cross-section. For some relations between the rheological coefficients of the model the governing equations are simplified and the corresponding theoretical estimations are obtained. Numerical calculations of the stress and velocity fields for the model parameters that correspond to the growing plant leaves are presented. Any difference in own growth rates of the adjacent layers leads to stretching of the tempered layer and compressing of the rapidly growing one that results in growth acceleration of the former and growth retardation of the latter. Thus the mechanical stress field can regulate coordinated growth of the laminated biological materials.