Analysis of wave propagation in thick-section composite laminates using effective moduli

Effective moduli for thick-section composite laminates were used to represent the laminates as homogeneous but anisotropic media. Harmonic waves propagating parallel and normal to the layering were considered. Dispersion curves for various stacking sequences were obtained from the effective modulus method and from exact layer-by-layer analysis. The results indicate that for long wavelengths, the effective modulus solutions converge to the exact solutions. As the wavelength decreases, the effective modulus solution starts to deviate from the exact solution. The amount of deviation depends on the mode of wave motion, stacking sequence, and number of plies in the laminate. The effective modulus model together with a global-local method were also used to study the transient response in a layered cylinder subjected to blast loading. The stress fields obtained from the effective modulus model agreed very well with those obtained using layer-by-layer analysis.