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Keywords: artificial immune system, identification, material constants, composite, laminate, finite element method, modal analysis, boundary element method, piezoelectricity.

Summary

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 [1] 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:

a): identification of material constants in composites, and
b): identification of piezoelectric material constants.

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.

References

1: S.T. Wierzchon, "Artificial Immune Systems, theory and applications", EXIT, (in Polish), 2001.

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Front Page Browse CCP CSETS CTR IJRT Other Authors Search Purchase Guide FAQ Contact us	Civil-Comp Proceedings ISSN 1759-3433 CCP: 93 PROCEEDINGS OF THE TENTH INTERNATIONAL CONFERENCE ON COMPUTATIONAL STRUCTURES TECHNOLOGY Edited by: Paper 136 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. Burczynski^1,2 ¹Department for Strength of Materials and Computational Mechanics, Silesian University of Technology, Gliwice, Poland ²Institute of Computer Science, Computational Intelligence Department, Cracow University of Technology, Cracow, Poland doi:10.4203/ccp.93.136 purchase the full-text of this paper Full Bibliographic Reference for this paper 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. Summary 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 [1] 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: a) identification of material constants in composites, and b) identification of piezoelectric material constants. 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. References 1 S.T. Wierzchon, "Artificial Immune Systems, theory and applications", EXIT, (in Polish), 2001. purchase the full-text of this paper (price £20) go to the previous paper go to the next paper return to the table of contents return to the book description purchase this book (price £145 +P&P)
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