Abstract :
An FEM parametric study of the stress distribution in orthotropic beam flanges was
performed. Several beam boundary conditions and cross sections were considered explicitly. The
practical variations of cross-sectional dimensions were extended in order to cover the case of thin
cover plates with stiffeners. In the FE analyses a two-dimensional plane stress model was used. An
empirical formula was established for the shear lag coefficient I, which is used for computing the
effective flange width B, = iB for stress calculations. Longitudinal flange stiffeners can be accounted
for by modifying the E/G ratio. The formula is accurate and gives good results even for small T,/r,,
and high E/G ratios, as is the case with fiber reinforced laminated composite plates with stiffeners.
Several existing analytical solutions, discussed in the paper, are not reliable for this case
