Emilio C. Nelli Silva
Dept. of Mechatronics, University of São Paulo, Brasil

Design of Piezocomposite Materials with High Performance

Piezocomposite materials are larged applied to acoustical devices such as sonars and ultrasonic transducers. Lately, their development has been based on the use of simple analytical models, test of prototypes, and analysis using the finite element method (FEM).

By changing the topology of these devices or their components an improvement in their performance characteristics can be obtained. Thus, in this work the potentiality of applying synthesis methods to design these smart materials is shown presenting the design of piezocomposite materials by using topology optimization combined with homogenization technique. Topology optimization is a general structural optimization method that combines optimization algorithm with finite element method. Homogenization method allows us to calculate the effective properties of a composite material knowing its unit cell topology. Using this method, a piezocomposite material with improved electromechanical efficiency is obtained by designing its unit cell topology. The examples presented show that the synthesis method is indeed a promising tool to design these smart materials, however, their application is still in the beginning. Thus, an emerging field that can take advantage of applying synthesis methods is the FGM (Functionally Graded Materials) materials. The techniques applied to manufacture these materials allow us to obtain a material with graded properties along its domain. This idea is close related to the principle used in the topology optimization formulation where the optimum solution actually consists of graded properties (“gray scale”). Nowadays, topology optimization scientists spend time developing techniques, such as filters, to come up with 0-1 results in topology optimizations due to the limitations of manufacturing techniques, however with FGM technology this will be no longer necessary in a near future. Thus, some preliminary results of topology optimization applied to the design of FGM structures are also presented to illustrate the potentiality for designing FGM smart materials.