Composite cylindrical shells under static and dynamic axial loading: An experimental campaign

Abstract

The results of an experimental investigation performed at the Politecnico di Milano inside the European project DAEDALOS on three composite cylindrical shells are here presented. At first, static buckling tests were performed under axial compression. Then, two types of dynamic tests were carried out: modal tests at different load levels before buckling and dynamic buckling tests applying an axial shortening of short duration. At the end, one shell was statically tested until final failure. The tests allow to understand the behavior of thin-walled cylindrical shells subjected to axial compression both in static and dynamic conditions. The results show the strength capacity of these structures to work in the post-buckling range with a capacity to sustain a load that is about 40% of the buckling load. The modal tests at different load levels allowed to observe that an increase of the load determines a reduction of the modal frequency and an increase of the damping. Large deformations are obtained before the final failure with out-of-plane displacements of almost 40mm and a shortening equal to about 26 times the buckling shortening.