Analyses of axisymmetric waves in layered piezoelectric rods and their composites

An exact treatment of the propagation of axisymmetric waves in coaxial anis otropic assembly of piezoelectric rod systems is presented. The rod system consists of an arbitrary number of coaxial layers, each possessing transver sely isotropic symmetry properties. The treatment, which is based on the tr ansfer matrix technique, is capable of deriving the dispersion relations fo r a variety of situations. These include the case of a single rod system th at is either embedded in an infinitely extended solid or fluid host or kept free. The procedure is also adapted to derive approximate solutions for th e cases of a periodic fiber distribution in a matrix material, which model unidirectional fiber-reinforced composites. The results are numerically ill ustrated for a widely used piezoelectric-polymer composite. It is seen that piezoelectric coupling can significantly change the morphology of the disp ersive behavior of the composite. (C) 2000 Acoustical Society of America. [ S0001-4966(00)02410-3].