Many structures such as boiler casings (Figure 7.1), submarine bulkheads, ship and barge hulls, ducts (Figure 7.2), aircraft components, and machine parts are designed in accordance with the general bending theory of plates. In this chapter, the pertinent equations of the bending theory of plates are developed, and examples are solved to demonstrate its applicability. These equations are applicable to thin plates subjected to small deflections. The majority of industrial applications encountered by the engineer fall under this category. Other theories dealing with thin plates with large deflections such as diaphragms, thick plates such as some tubesheets in heat exchangers, and composite and laminated plates in some aircraft components are beyond the scope of this book. Many of the references given at the end of the book delve into such theories, and the interested reader is encouraged to read them.