Pressure vessels are used to hold fluids such as liquids or gases that must be stored at relatively high pressures.
Pressure vessels may be found in many settings such as chemical plants, airplanes, ships, submersible vehicles, and manufacturing processes.
We will consider thin-walled pressure vessels. In general, a vessel can be classified as thin-walled if the ratio of the inside radius to the wall thickness is greater than about 10.
Thin-walled pressure vessels are classified as shell structures. The wall comprising the vessel is also called the shell.