Identification of damages in composite multilayered cylindrical panels with delaminations

In this study, effective theoretical and computational (the finite element method) procedures are introduced and used to characterize the dynamic behavior of beams and of cylindrical panels with circular cross-section; both structures have the single delamination between laminate layers. Based on the computed results it is possible to determine the effect of delamination on the overall structural dynamic behavior. Those results are used to quantify the difference between the results of the relevant parameters in the cases of perfect and defected structures. Usually, the wave propagation can be observed with the use of piezoelectric sensors. Therefore, in the next step of our analysis we modeled delaminated structures with a finite number of PZT sensors to consider also their influence on the structural dynamic response. The numerical analysis have been conducted with the use of 3D finite elements. It deals with the analysis of a cylindrical shell with an axisymmetric delamination and of a cylindrical panel having a square local delamination. A lot of numerical results allow us to understand better the influence of various parameters on the form of wave propagation in cylindrical multilayered shells. The numerical results are also validated by an experimental analysis for cylindrical panels.