N. Mole

Parallel computing with load balancing on heterogeneous distributed systems

In the present work, the parallelization of the solution of a system of linear equations, in the framework of finite element computational analyses, is dealt with. As the substructuring method is used, the basic idea refers to a way of decomposing the considered spatial domain, discretized by the finite elements, into a finite set of non-overlapping subdomains, each assigned to an individual processor and computationally analysed in parallel. Considering the fact that Personal Computers and Work Stations are still the most frequently used computers, a parallel computational platform can be built by connecting the available computers into a computer network. The incorporated computers being usually of different computational power and memory size, the efficiency of parallel computations on such a heterogeneous distributed system depends mainly on proper load balance. To cope the balance problem, an algorithm for the efficient load balance for structured and free 2D quadrilateral finite element meshes based on the rearrangement of elements among respective subdomains, has been developed.

Modelling of the Coupled Electromagnetic-Thermomechanical Problem and its Application to Heat Treatment

When a metallic workpiece is subjected to heat treatment the crucial role in obtaining the final mechanical properties plays, apart from that of the initial chemical composition, the thermal history, ie. heating and cooling. Understanding of mechanisms and identification of parameters influencing the phase transformation kinetics is therefore of major importance for designing a heat treatment technology. The considered problem is characterized by extreme complexity and its investigation demands an interdisciplinary knowledge. Although a vast empirical knowledge about the problem, which is rather complex, has been gained, experience proves that it is often not sufficient. It seems that mathematical modelling, when based on experimentally verified models and adequately numerically modelled, could enable through a computer simulation an efficient design of more complex problems in a very objective and reliable way.