Kinematic Theory for Buckling of Open and Closed Section Thin-Walled Composite Beams

Abstract

A new theory for the analysis of composite beams of open and closed cross section has been developed. The theory takes into account deformation in the plane of the cross section due to anticlastic curvature. Box beams and I-sections containing cross-sectional elements that are angle-ply midplane symmetric laminates have been analyzed with the new theory. It is shown that the inclusion of the anticlastic curvature substantially reduces the predicted buckling loads for these beams. The effect is most pronounced when there are 45° or near 45° layers in the laminates. In addition, box beams with a more optimized lamination scheme are analyzed. It is shown that the anticlastic curvature terms are important when buckling about the weak axis is considered.