Contents of Journal of Mechanical Engineering 52, 6 (2001)


O. KROPAC: Characteristics of longitudinal road unevenness: definitions, estimation and use 325 J. MURIN, V. KUTIS: Solution of non-incremental FEM equations of non-linear continuum 360 A. USCILOWSKA: Equilibrium problem of a multi-articulated tower immersed in fluid 372


Abstracts



Characteristics of longitudinal road unevenness: definitions, estimation and use

O. KROPAC

A general overview of the present state-of-the-art of main problems connected with the longitudinal unevenness of roads is given. After a short historical introduction the following aspects are discussed: characteristics of random and local unevenness; methods of providing primary data from real roads including relevant measuring devices; processing of data and forms of presenting results including their precision estimation; state of standardization effort; generalized characteristics reflecting deviations from standard analytical models; main areas of exploitation of different characteristics of unevenness. The mutual interaction between road and travelling vehicle and methods of statistical dynamics form the background of the conception applied in this paper; accordingly, characteristics, which follow from this approach, are preferably recommended for use.


Solution of non-incremental FEM equations of non-linear continuum

J. MURIN, V. KUTIS

This paper deals with solving non-incremental non-linear FEM equations of non-linear continua which were derived without linearization and without using the mid-configuration (by describing the deformation motion of a body). Two iterative solution algorithms of these equations are proposed that use the full non-linear and non-linear tangent stiffness matrices of finite elements. The convergence and accuracy of our iterative algorithms are compared with results which were obtained by the ANSYS computer code (incremental and linearized FEM equations). These numerical experiments were performed for several bar constructions.


Equilibrium problem of a multi-articulated tower immersed in fluid

A. USCILOWSKA

One kind of more and more popular offshore structures are articulated towers or manipulators of robots partially or fully immersed in water. This paper is a consideration of the equilibrium positions of a multi-articulated tower fully or partially immersed in still fluid. The tower is treated as an inverted multi-pendulum. The problem considered is a static one. The equilibrium positions of the multi-articulated tower are found by solving the equilibrium equations for forces and moments. The analysis of potential energy of the system (multi-articulated tower/fluid) is used to determine the stability of calculated equilibrium positions of the considered tower. The results of numerical calculations are presented and discussed.