Buckling of tension-loaded thin-walled composite plates with cut-outs

Plane plates subjected to tensile loads are usually not considered to fail due to buckling. However if a plate contains a cut-out, regions of compressive stresses arise under a uniaxial tensile load. In thin-walled orthotropic composite plates these compressive stresses may cause local buckling. In general the stress concentration factors of cut-outs are very high, thus the buckling limits will not be exceeded before fracture. However cut-outs, optimised by a shape optimisation method, run risk to initiate buckling before exceeding the fracture load because the stress concentration factors for these cut-outs are very low. In this paper the influence of the shape of optimised cut-outs on the buckling behaviour is investigated. Besides the critical load the under-critical and post-critical behaviour of geometrical imperfect orthotropic composite plates is analysed. Methods that prevent local buckling under tensile stresses are discussed in order to provide the full advantage of optimised cut-outs.