Investigations on the static and dynamic response of cfrp anisogrid cylindrical shells

Abstract

Polymer composites are becoming more popular in the aerospace, marine, and automotive sectors due to their high strength-to-weight ratio, directional strength, and stiffness. Stringer-stiffened and sandwich structures are two of the most common structural ideas employed in aircraft today. Stiffened structures and sandwich structures are both built on the principle of load-carrying skins, whereas ribs and core give great bending stiffness and resistance to shear and compression. Typically, none of these structures enables us to considerably decrease the structural weight. Lattice composite structures, in contrast to stringer and sandwich structures, rely on the ribs to provide membrane and bending stiffness. Composite cylinders with stiffened filament wound grids belong to a family of structures with exceptionally high mass and reliability efficiency. On the other hand, composite shell structures have always struggled with an epidemic of damage caused by impact. Even though the impact has a relatively modest velocity, the composite shell structures may still suffer a significant reduction in their load-carrying capacity owing to the several mechanisms of failure. The present thesis work is developed within the framework of presenting an economical and reliable manufacturing method for making an anisogrid cylindrical shell, evaluating the static axial compression behavior and low-velocity axial impact response of anisogrid lattice cylindrical shell structures. newlineAnisogrid shell was modeled as a 3D frame structure with circumferential and helical ribs that were subjected to tension and compression. In a lattice shell structure, the ribs serve as the major load-bearing components. newline