## Chapter 13 Plates and Shells

### Part A—Bending of Thin Plates

### 13.1 Basic Assumptions

Plates and shells are initially flat and curved structural elements, respectively, with thicknesses small compared with the remaining dimensions. In Part A of this chapter, we consider plates, for which it is usual to divide the thickness *t* into equal halves by a plane parallel to the faces. This plane is termed the *midsurface* of the plate. The plate thickness is measured in a direction normal to the midsurface at each point under consideration. Plates of technical significance are often defined as *thin* when the ratio of the thickness to the smaller span length is less than 1/20. We here treat the small deflection theory of homogeneous, uniform thin plates, leaving ...