ASYMPTOTIC HOMOGENIZATION OF LAMINATED PIEZOCOMPOSITE MATERIALS

The objective of this paper is to apply the technique of asymptotic ho mogenization to determine the effective elastic, piezoelectric and die lectric moduli of a laminated piezocomposite medium with a periodic st ructure. Each periodic cell of the medium can possess any finite numbe r of piezoelectric layers. The general formulae obtained are a general ization of those that appear in chapter 5 of Pobedria (Pobedria, B. E. (1984) Mechanics of Composite Materials. Moscow State University Pres s, Moscow (in Russian)) and involve both cases of Newnham's connectivi ty theory (Newnham, R. E., Skinner, D. P. and Cross, L. E. (1978) Conn ectivity and piezoelectric-pyroelectric composites. Materials Research Bulletin 13, 525-536) for layered piezoelectric media. We calculate e xplicitly overall effective characteristics for three examples of such layered media. For the particular case of a binary layered medium, co nnected in parallel, with transversely isotropic constituents such for mulae transform exactly to the formulae for effective constants obtain ed by Benveniste et al. (1992) in which a different method of homogeni zation was used. Finally, we apply these results to a piezocomposite m aterial and obtain new piezoelectric with better global properties for hydrophone applications. (C) 1997 Elsevier Science Ltd.