Stiffness of thin-walled structures

The earlier chapters of this book have examined in detail an introduction to how flat panels behave under in-plane loads or moments. The thin flat plate, and (to an approximation) the thin singly-curved panel, is a two-dimensional structural element. It is clearly the fundamental building block for composite structures, and it is therefore essential that the behaviour of the flat plate is well-understood before looking at more complicated structures. Even with the detail studied in the previous chapters, we have not covered all possible types of loading situations — transverse loading of plates is obviously missing — but to cover this would require a much deeper knowledge of the theory of plates and shells than we have space to cover within the scope of Chapter 2 for isotropic materials and in the rest of this book for composites: for further details the reader is advised to consult more advanced texts cited in the bibliography.