Shear Lag of Open and Closed Thin-walled Laminated Composite Beams

Abstract

Harmonic technique for shear lag analysis is extended to thin-walled open and closed composite beams. The cross section laminates are considered in isolation and are loaded by the shear flow and the axial stress resultants. In addition, the equilibrium and compatibility equations are established for each laminate and the boundary conditions at the laminate edges are satisfied. The shear lag model is incorporated into a beam model, from which the beam stiffness coefficients, shear flow, and stress resultants are obtained. Explicit shear lag formulas for various sections are developed. Composite beams are tested in bending for verification of the analytical model predictions, which agree closely with the experimental results.