Effects of Fiber Orientation on Out-of-plane and In-plane Natural Frequencies of Angle-ply Laminated Composite Arches

Variation of natural frequencies of in-plane and out-of-plane vibrations of 4-layer angle-ply composite arch with respect to fiber angle is investigated by the finite element method. The arch has clamped-clamped boundary conditions. It is concluded that the fiber angle is particularly important for in-plane vibrations. For any certain value of radius/length ratio of the arch, the natural frequency can be either increased or decreased with respect to fiber angle; therefore, angle-ply lamination can be preferable to cross-ply lamination. On the other hand, the effect of fiber angle on the out-of-plane frequencies can be used as an advantage in the design of laminated composite arches.