A study of the vibration and lay-up optimization of rotating cross-ply laminated nanocomposite blades

A comprehensive understanding of the vibration characteristics of rotating blades is critical to avoid resonance fracture. This paper presents the vibration analysis and lay-up optimization of rotating pre-twisted laminated functionally graded CNTs reinforced composite (FG-CNTRC) shallow conical shells. A numerical shallow conical shell model is proposed, and the displacement fields of the shell model are described via the first-order shear deformation theory. Considering the rotating speed, the governing equation of the rotating pre-twisted laminated conical shell is derived, and then solved using the meshless kp-Ritz method. We carry out the comparison studies to demonstrate the accuracy and efficiency of the present model in dealing with the vibrations of this kind of structures. Detailed parametric studies are then performed and demonstrate that the CNT configuration, pre-twisted angle, and stacking sequence play essential roles in vibration behaviors of rotating FG-CNTRC blade. With the nondimensional frequency parameter being the optimization objective function, a genetic algorithm is employed to search for the optimal layering sequence of the rotating shallow conical shells. The optimized results demonstrate that the GA serves as a useful tool for sequence optimization of rotating blade in terms of improving the vibration characteristics.