Wave propagation in piezoelectric phononic and nesting Fibonacci composite laminates: a parametric study

In the present study, the plane wave expansion (PWE) and the stiffness matrix method (SMM) are employed to predict the transmission spectrum of piezoelectric phononic and quasi-periodic composite laminates with and without a defect layer. We propose a two-dimensional (2D) geometric system that combines two sub-models: piezoelectric phononic or quasi-periodic strips along the x-direction and periodic laminates in the z-direction. Investigations are conducted to predict the transmission coefficient variation within a high range of frequencies excitation, in quasi-periodic composite laminates and phononic composite laminates with various generation numbers. Numerical simulations show that the introduction of a non-periodic structure (nesting Fibonacci), a defect layer, as well as increasing the generation number increase the number of band gaps. Furthermore, the effect of a defect layer on the transmission spectrum of phononic or quasi-periodic composite laminates is highlighted. Finally, a parametric investigation varying the thickness of the defect layer is carried out.