Ultrasonic Characterization of Multilayered Thick Composite Plates

Although propagation of guided (Lamb) waves in a homogeneous isotropic plate has been studied extensively in the past, relatively few studies have been reported that deal with homogeneous anisotropic plate. In a recent paper Nayfeh and Chimenti [1] have reviewed the literature and they have presented results for dispersion of free Lamb waves in a homogeneous anisotropic plate. The present study is concerned with dispersion of free guided waves in a cross-ply laminated plate. Since laminated composite plates are finding usage in a variety of applications, there is a need to understand their response under dynamic loading. Of particular interest for this purpose is the characteristic dispersion of modes of propagation in a multi-layered laminated plate. This dispersion behavior influences the dynamic response and it can also be used to ultrasonically characterize the mechanical properties of the laminated plate. The motivation is to present a systematic study of the influence of layering on the dispersion behavior