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PROCEEDINGS OF THE TENTH INTERNATIONAL CONFERENCE ON COMPUTATIONAL STRUCTURES TECHNOLOGY
An Artificial Immune System in the Identification of Material Constants in Composites and Piezoelectrics
A. Poteralski1, M. Szczepanik1, W. Kus1, W. Beluch1, G. Dziatkiewicz1 and T. Burczynski1,2
1Department for Strength of Materials and Computational Mechanics, Silesian University of Technology, Gliwice, Poland
A. Poteralski, M. Szczepanik, W. Kus, W. Beluch, G. Dziatkiewicz, T. Burczynski, "An Artificial Immune System in the Identification of Material Constants in Composites and Piezoelectrics", in , (Editors), "Proceedings of the Tenth International Conference on Computational Structures Technology", Civil-Comp Press, Stirlingshire, UK, Paper 136, 2010. doi:10.4203/ccp.93.136
Keywords: artificial immune system, identification, material constants, composite, laminate, finite element method, modal analysis, boundary element method, piezoelectricity.
This paper is devoted to the application of the artificial immune system (AIS) and finite element and boundary element identification problems of material constants. A new method of identification of material constants in composites and piezoelectrics using AIS is presented.
The artificial immune systems  are developed on the basis of a mechanism discovered in biological immune systems. The AIS take only a few elements from the biological immune systems. The most frequently used are the mutation of the B-cells, proliferation, memory cells, and recognition by using the B and T-cells. The unknown global optimum is the searched pathogen. The memory cells contain design variables and proliferate during the optimization process. The B-cells created from memory cells undergo mutation. The B-cells evaluate and better ones exchange memory cells.
Composites are materials which consist of at least two different constituents coupled on the macroscopic level. Multilayered laminates are probably the most often used composite materials due to their high mechanical and strength properties related to the specific gravity. These structures are modelled and analyzed using the finite element method (FEM).
The piezoelectricity phenomenon is widely used in many devices, for example, sensors, actuators, micro-electro-mechanical systems and transducers. The ceramic piezoelectrics are solids, which belong to the hexagonal symmetry class of the crystals. These crystalic solids have anisotropic physical properties, therefore in the paper a homogeneous, transversal isotropic, linear elastic and dielectric model of the piezoelectric material is chosen. These structures are modelled and analyzed using the boundary element method (BEM).
Coupling the FEM or the BEM and the AIS gives an effective and efficient alternative identification tool, which enables a large class of the identification problems of mechanical structures to be solved. In the full paper two numerical examples are presented:
The numerical examples confirm the efficiency of the proposed new identification method and demonstrate that the method based on immune computation is an effective technique for solving computer aided optimal design problems. The main advantage of the AIS, contrary to gradient methods of optimization, is the fact that it does not need any information about the gradient of the fitness function.