Experimental Investigations on the Buckling Behavior of Unstiffened, Lozenge Grid-Stiffened and Lozenge Lattice Composite Cylindrical Shells Under Axial Loading

In this article, three types of unstiffened, grid-stiffened and lattice composite cylindrical shells are experimentally investigated under quasi-static axial loading. The E-glass/Epoxy composite cylindrical shells are manufactured by filament winding technique. The main purpose of this paper is to investigate the effect of stiffener on the buckling behavior of unstiffened shell and also the interaction between the grid stiffener and the outer shell. Experimental results show that the lattice shell has a negligible buckling load in comparison with the unstiffened and grid-stiffened composite cylindrical shells. Meanwhile, it is worth to notice that using of grid stiffener leads to increase the buckling load of the unstiffened shell and increase the buckling displacement as well. Based on the experimental data, the grid-stiffened shell has the highest buckling load, while the lattice stiffener has the lowest buckling load. Also, results from the literature and this paper reveal that the specific buckling load of the unstiffened shells is more than the stiffened shell, regardless of the geometry of the stiffener. Thus, it may be concluded that these kinds of structures are more efficient in non-moving applications such as tower structures, stationary fuel tanks and stationary energy absorbing structures.