Buckling of helically wound composite cylinders under uniform external pressure

This study investigated the buckling behaviours of helically wound composite cylinders subjected to uniform external pressure. Three composite cylinders with lengths 180, 280, and 380 mm were manufactured through ±55° winding. Cylinders with a wall thickness of 3.12 mm and inner radius of 103 mm were constructed from carbon fibre reinforced resin matrix composites. Externally hydrostatic tests were conducted to determine the collapse strength and postcollapse modes of the three cylinders. Furthermore, the analytical, linear eigenvalue, and Riks methods were used to study their buckling behaviours. The experimental, analytical, and numerical data agreed well with each other. The Riks method considers Hashin damage initiation and linear damage evolution and can therefore be used to reasonably estimate the postcollapse modes of cylinders.