VIBRATION AND OPTIMUM DESIGN OF ROTATING LAMINATED BLADES

The vibration and optimum design of rotating laminated blade subject t o constraints on the dynamic behavior are investigated. Restrictions o n multiple natural frequencies, as well as maximum dynamic deflections of rotating laminated blades, are considered as constraints of the dy namic behavior of the system. Aerodynamic forces acting on the blade a re simulated as harmonic excitations. The optimality criterion method and the modified method of feasible directions have been successfully developed for optimizing the weight of a rotating laminated blade. Eff ects of radius of the disc, aspect ratio and rotating speed on the sys tem dynamic behaviors and/or the optimum design are also studied. The vibration analysis shows that most of the bending modes can be signifi cantly affected by the rotating speed and the radius of the disc. Resu lts also show that the optimum weight with constraints on the dynamic response is higher than that with frequency constraints. Moreover, res ults show that the weight of a rotating laminated blade can be greatly reduced at an optimum stage.