Local buckling of laminated composite beams based on different plate theories

Abstract

AbstractThis paper presents an approximate approach for the local buckling analysis of prismatic composite laminated beams under uniaxial compression wherein the segments of the beams (i.e. flanges and webs) are assumed to be moderately thick so that advanced plate theories that transcend the restrictions of classical laminated plate theory (CLPT) need to be employed. We present a novel approximate analysis method based on the so‐called discrete plate approach during which the segment of interest is separated from the beam and is subjected to rotational restraints at the cutting edges. The analysis itself employs rather simple shape functions for the local buckling modes in conjunction with a Rayleigh‐type approach using the principle of minimum elastic potential of the buckled segment wherein we use the kinematic assumptions of Reddy's third‐order shear deformation theory (TSDT). The results are compared to comparative computations based on CLPT and first‐order shear deformation theory (FSDT), and a good agreement is found especially between FSDT and TSDT which lends credibility to the present approach, however neither employing the strict limitations of CLPT imposed by Kirchhoff's classical kinematic assumptions, nor requiring shear correction factors as they are generally required in the framework of FSDT and which is still a topic of on‐going research. (© 2017 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)