CHAPTER 1 - General Introduction to Shell Theory

Abstract

This chapter presents a general introduction to shell theory. A shell structure may be defined as the solid material enclosed between two closely spaced doubly curved surfaces, the distance between these two surfaces being the thickness of the shell. If the thickness is small compared with the overall dimensions of the bounding surfaces then the shell is defined as a thin shell; if not, it is termed thick. This chapter discusses primarily the analysis of thin shells. Shell-like structures are familiar enough in nature, but the use of such structures as containers, aircraft fuselages, submarine hulls and roofing structures is only of recent origin. The inherent strength of shells for structures has not been utilized much in the past is probably because of the difficulty in obtaining suitable material with which to construct them. Such difficulties no longer exist, and shell structures in general are these days constructed of such varied materials as steel, light alloy, plastics, wood, and reinforced concrete.