Acoustic material signature of fiber reinforced composites

Potential use of acoustic microscopy at low frequency for determining elastic properties and characterizing internal defects have been recognized in the recent years. In this paper a theory is presented for the calculation of the acoustic material signature of an orthotropic half-space overlain by a fluid. The analysis is carried out for low frequency acoustic waves generated by a cylindrical transducer without a lens rod and the response is measured by a line receiver. Several new features of the material signature and their possible use in fiber reinforced composite material characterization are indicated.