Vibration analysis of rotating delaminated non-uniform composite plates

In this study, the free and forced vibration responses of rotating delaminated thickness tapered (non-uniform) composite plates are investigated. The governing differential equations of motion of the various models of a rotating mid-plane delaminated thickness tapered laminated composite plate are presented in the finite element formulation based on classical laminated plate theory (CLPT) including the various rotational effects. The finite element formulation developed for the free vibration analysis of rotating delaminated tapered composite plate is validated by comparing the natural frequencies evaluated using the present finite element method (FEM) with those obtained from the experimental measurements. Various parametric studies are also performed to study the effect of taper models, rotational speed, length and location of delamination on the dynamic characteristics of the tapered composite structure. It was observed that the percentage of decrease in natural frequencies of delaminated composite plate when compared to intact composite plate at lower modes is lesser than those compared to higher modes irrespective taper models and rotating speeds considered. Further, it was noticed that the decreasing percentage of natural frequencies of the mid-plane delaminated different taper models of composite plate over intact plate increase in the order of TM2, TM1, TM3 and uniform composite.