Contents of Journal of Mechanical Engineering 55, 3 (2004) 


 
RYCHLIK, M., MORZYNSKI, M., NOWAK, M., STANKIEWICZ, W., LODYGOWSKI, T.,
OGURKOWSKA, M.: Acquisition and transformation of biomedical objects to
CAD systems                                                               121

KVASNICKA, P., PALCAK, F.: Optimization of the suspension damper 
on a quarter car model using ride comfort criteria in a multiobjective
function                                                                  136
             
VLK, F., KOLLHAMMER, D.: Mathematical simulation of vehicle handling
(in Czech)                                                                151

SLIZEK, O., ORAVSKY, V.: Sensitivity analysis of chosen parameters on 
the properties of rectangular plate and cylindrical shell (in Slovak)     166

Abstracts



Acquisition and transformation of biomedical objects to CAD systems

MICHAL RYCHLIK, MAREK MORZYNSKI, MICHAL NOWAK, WITOLD STANKIEWICZ, TOMASZ LODYGOWSKI, MALGORZATA B. OGURKOWSKA

The paper addresses data acquisition and processing for three-dimensional biomedical models. The aim is to reconstruct the topology of the organ as well as to construct on this basis the consistent computational grid. The additional data like density are to be included. The emphasis is on practical problems encountered during such procedure. On the example of human vertebra, methods of generation of the volume tetrahedral mesh for FEM are discussed. Authors present methods of reconstruction 3D models available in CAD software and present concept of practical use of empirical eigenmodes (Proper Orthogonal Decomposition - POD) for reconstruction of complex biomechanical models. The empirical eigenmodes can be used also for modelling the volume properties (like tissue density) what is important in FEM stress analysis. This paper is a part of the project of the Polish State Committee for Scientific Research.

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Optimization of the suspension damper on a quarter car model using ride comfort criteria in a multiobjective function

PAVEL KVASNICKA, FRANTISEK PALCAK

After theoretical background for the ride comfort and driving safety optimization, a study of the influence of the ride comfort criteria to a multiobjective optimization of a suspension damper is presented in this paper. The objective function ObjSCD was constructed as a weighted combination of the ride comfort perception quantity AvT, standard deviation (sigma)Fn of the normal tire force, and standard deviation (sigma)D of the relative displacement of the wheel to the car body. For the ride comfort perception optimization and the car model identification a MATLAB toolbox was developed.

Mathematical simulation of vehicle handling

FRANTISEK VLK, DAVID KOLLHAMMER

The paper deals with mathematical modelling of vehicle handling. The meaning of simulation and its relationship to the engineering industry is explained in the introduction. Theoretical keystones from which the simulation starts are described here. Whole model starts from basic physical rightfulness and mathematical description of actions, which arise from vehicle motion. There are described selected models of simulation. System of differential equations is solved by Runge-Kutta numerical integration. Some illustrations of the results solved by this method are presented here, too. The principle of verification of the results and possibility of future development are also discussed in this thesis.

Sensitivity analysis of chosen parameters on the properties of rectangular plate and cylindrical shell

OLDRICH SLIZEK, VLADIMIR ORAVSKY

Influence of parameters of multi-parameter systems upon their behaviour is investigated by means of a special sensitivity analysis. After statistical evaluation of special criteria, one can find a matrix of influence and a sequence of dominance of parameters and thus obtain the full review of influence. At the same time one can judge, which parameter is mostly suitable for variation to reach effective change of chosen output quantity.
The above general approach has been applied to a rectangular plate and a cylindrical shell, whereby influence of their geometrical and material parameters upon their eigenfrequency has been investigated. Sensitivity analysis of the rectangular plate has served only for verification. The main effort has been focused upon sensitivity analysis of a thin cylindrical shell, where influence of individual parameters is not evident from analytical expressions.
The results of investigation are tabulated and presented in the form of a full review of influence and representative diagrams, where influence of some parameters upon eigenfrequency is plotted and evaluated.