Effect of Shear Lag on Buckling Behavior of Hat Shaped Laminated Composite Box Sections

A new class of materials, laminated composites is increasingly being used for a wide range of civil infrastructure applications and aerospace structures due to their high strength, stiffness, lightweight and durability. It is generally assumed in bending theory that plane sections remain plane after loading, this assumption does not hold for box beams with wide flanges. Shear lag effect can bring non uniform normal stress distribution on flanges; it would affect the strength design of thin-walled beams. The strength of thin walled members is governed by the buckling criterion. In this paper effect of shear lag on buckling behavior of laminated composites is examined. The present study investigates about analysis of hat shaped box beam model for buckling behavior and approach for finding out the shear lag effects on symmetrically laminated graphite epoxy thin walled composite box beams under flexural loading. A parametric study has been carried out using the homogeneous and orthotropic finite element models created by ANSYS16. Influences of orthotropic parameter and cross sectional parameter are studied.