In the paper a general survey of existing finite element (FE) models is presented using a conceptual description in diagram form, which was initiated in paper [1]. The analysis is focused on the description of FE models, which is uniform in its concept but specific for each FE type. All FE models are associated with certain variational principles (and their stationarity conditions) in their original or modified versions. The diagrams are used to visualize the equations which are satisfied inside an individual FE and on interelement boundaries. The use of conceptual diagrams is very convenient in the presentation of finite element method (FEM), it simplifies the understanding and teaching of this method.

A. Smykla. A technique of stretched meshes in the modelling of complex 3D structures in Finite Elements Analysis (FEA) applications. CAMES 2006 (13)

The paper presents the computational approach to the process of creation of complex three-dimensional finite elements models. The data are automatically received by the measuring unit and sent directly to the computer. The process of numerical treatment of measuring points' coordinates is shown. As an example of above mentioned method, the construction of human femoral head model is demonstrated. Finally the geometrical model of the object, which can be used by PATRAN system is obtain. Paper presents results of numerical calculations and compares it with a photoelastic experiment.

A. Rajagopal, S. M. Sivakumar. Optimality of grids based on a combined r-h adaptive strategy. CAMES 2006 (13)

A critical review of earlier works on optimality of finite element grids has been made. A material force method of r-adaption to obtain optimal initial grids has been described. The study focuses on determining the configurational driving force and its convergence rate across an interior patch node for one-dimensional linear, quadratic element and two-dimensional bilinear quadrilateral elements. Numerical implementation is made on one and two-dimensional problems. Various aspects considered to define optimality in earlier works along with their predefined guidelines have also been worked out with some modifications for the material force method and it is shown that this method of adaption provides good optimal grids. The method is advantageous owing to its physical basis and mathematical vigor than earlier works. Based on the numerical studies conducted a combined adaptive strategy incorporating node disposition and mesh enrichment has been evolved to obtain an optimal mesh for a specified accuracy.

M. F. Robbe, M. Lepareux, F. Casadei. Simulation of the MARA 10 test representing a core disruptive accident. CAMES 2006 (13)

In the case of a Hypothetical Core Disruptive Accident in a Liquid Metal Fast Breeder Reactor, the core of the nuclear reactor is assumed to have partially melted, and the interaction between molten fuel and liquid sodium creates a high-pressure gas bubble in the core. The violent expansion of this bubble loads and deforms the reactor vessel and the internal structures, thus endangering the safety of the nuclear plant.
The MARA 10 experimental test simulates a HCDA in a 1/30-scale mock-up schematising simply a reactor block. The vessel is filled with water, topped with an air blanket. The test is fired using an explosive charge. This paper presents the numerical models implemented in the EUROPLEXUS code, and a numerical simulation of the test. The evolution of the fluid flows and the deformations of structures are analysed in detail to understand the progress of the explosive phenomenon.
*Keywords:* accident, simulation, dynamic, mechanics, nuclear, reactor, explosion.

TJ. Bravo-Castillero, F. J. Sabina, R. Guinovart-Diaz, R. Rodriguez-Ramos, O. C. Valdiviezo-Mijangos, J. C. Sabina-de-Lis. Effective elastic properties of periodic fibrous composites. Limit cases. Applications to porous and nonlinear materials. CAMES 2006 (13)

The goal of this contribution is to provide, based on the asymptotic homogenization method, helpful exact formulae to compute the overall stiffnesses and engineering moduli of a transversely isotropic two-phase fibre reinforced composite with isotropic constituents. Comparison of the exact solution with known bounds is shown. In certain cases a bound is very close to the exact solution over a large interval. The bound then could be used as a good approximation to the exact solution. The exact formulae explicitly display Avellaneda and Swart's microestructural parameters, which have a physical meaning, and provide formulae for them. Hill's universal relations follow from the formulae. Limiting cases of rigid and empty fibers are included. An application of these results to improve bounds for the effective energy density of nonlinear dielectric fibrous composites is shown. Another application is related to bone poroelasticity.
*Keywords:* fibers, mechanical properties, microstructure, anisotropy, elastic properties.

J. Mackerle. Finite element computational dynamics of rotating systems, an addendum (A bibliography (1998-2004)). CAMES 2006 (13)

Gives a bibliographical review of the finite element analyses of rotating systems from the theoretical as well as practical points of view. The bibliography lists references to papers, conference proceedings and theses/dissertations that were published between 1998-2004. It is a continuation of the author's earlier bibliography with the same title published in *Shock Vibration 6* (1999) 209-222 where papers published between 1994-1998 are listed. At the end of this paper 479 references are listed.
*Keywords:* finite elements, rotor dynamics, shafts, blades, bibliography.

P. Orantek. An intelligent computing technique in identification problems. CAMES 2006 (13)

The paper is devoted to the application of the evolutionary algorithms, gradient methods and artificial neural networks to identification problems in mechanical structures. The special intelligent computing technique (ICT) of global optimization is proposed. The ICT is based on the two-stage strategy. In the first stage the evolutionary algorithm is used as the global optimization method. In the second stage the special local method which combines the gradient method and the artificial neural network is applied. The presented technique has many advantages: (i) it can be applied to problems in which the sensitivity is very hard to compute, (ii) it allows shortening the computing time. The key problem of the presented approach is the application of the artificial neural network to compute the sensitivity analysis. Several numerical tests and examples are presented.