Experimental and numerical study of buckling response of composite shells compressed transversely between rigid platens

This paper aims at describing the buckling behaviour of transversely loaded composite shell structures. Two distinctive glass fabrics, woven and knitted, embedded in the same thermoplastic matrix, polypropylene, were utilised to produce the composites to be used as subject materials. Curved strips with fixed curvature and span, but with different number of plies and orientations, were compressed between two rigid flat platens. Load-displacement responses and deformed shapes were examined using experiments and numerical simulations based on a general finite element code, LUSAS®. As the nonlinear collapse is the buckling mode evident in the experimental tests, a nonlinear stress analysis technique has been adopted to simulate the buckling responses. Single-ply strips, both for woven and knitted, display limit point symmetrical buckling failure that shows good agreement with the predictions in terms of critical load and buckling mode. In the cases of multi-ply construction, the modes of failure for woven fabric specimens are by means of delaminations while the multi-ply knitted shells still exhibit similar behaviours to that of the single-ply specimens.