Deflection of Composite Cantilever Beams with a Constant I-Cross Section

Abstract

Laminated composite beams are widely used as structural components in aerospace and wind energy industries. For airplane wings and wind turbine blades, the beams, commonly called spars, provide principal stiffness against bending deformation of the structures. The present work is focused on composite cantilever beams with a constant I-cross section. A unidirectional (UD) Glass/Epoxy lamina was chosen for composite material. The overall dimension of the beam is 50 × 55.2 × 2,500 mm. Various stacking sequences were assigned to the flanges and the web of the beam. A uniform distributed load was applied to the upper flange. The deflection results from First-Order Shear Deformation Theory (FSDT) and Finite Element Analysis (FEA) are in good agreement. The effective longitudinal modulus (Ex) of the flanges has strong influence on the bending stiffness and the beam deflection. Understanding important roles of materials and beam construction can help improving the design of I-beams. The validated FEA procedure can be extended to the analysis of realistic spars, which is based on an I-cross section plus curve, taper, and twist along the length.