Longitudinal elastic wave propagation in laminated composites with bonds

We extended the finite element displacement method to study the propagation of longitudinal elastic waves in laminated composite with bonds. The geometric arrangement of the composite model considered in this paper is treated as a special type of a trilaminated composite in which each of its major constituents is sandwiched between two bonding layers. The dispersion characteristics of this model are presented here and compared with some exact results. The exact dispersion relation for the trilaminated composite is formally obtained by solving the field equations subjected to continuity conditions at materials' interfaces. Also included in the comparisons are the results obtained with continuum theory with microstructure. It is found that numerical results of finite element analysis, continuum theory and exact analysis corelate well especially for the lower modes of wave propagation.