Experimental Investigation of the Dynamic Characteristics of Laminated Composite Beams

The laminated composite beams are basic structural components used in a variety of engineering structures such as airplane wings, helicopter blades and turbine blades as well as many others in the aerospace, mechanical, and civil industries. An important element in the dynamic analysis of composite beams is the computation of their natural frequencies and mode shapes. This is important because composite beam structures often operate in complex environmental conditions and are frequently exposed to a variety of dynamic excitations. In this paper, a combined finite element and experimental approach is used to characterize the vibration behavior of composite beams. To this end, some beams are made using the hand-lay-up process. Glass fiber is used as reinforcement in the form of bidirectional fabric and general purpose polyester resin as matrix for the composite material of beams. Experimental dynamic tests are carried out using specimens with different fiber orientations. From the results, the influence of fiber orientations on the flexural natural frequencies is investigated. Also, these experiments are used to validate the results obtained from the finite element software ANSYS. Index Terms – Composite beams, Dynamic tests, Finite element method, Natural frequencies Manuscript submitted May 10, 2010. Mohammed F. Aly is with the Department of Industrial Engineering, Fayoum University, Fayoum, Egypt. (Phone: +20101692563), (email: [email protected] and [email protected],). I. G. M. Goda is with the Department of Industrial Engineering, Fayoum University, Fayoum, Egypt. (Phone: +20115838789), (email: [email protected]). Galal A. Hassan is with the Department of Mechanical Design and Production, Cairo University, Cairo, Egypt. (Phone: +20103541315), (email: [email protected]).