Elastic analysis of thick-walled, filament-wound cylinders under combined pressure and longitudinal loads

Abstract

Fiber-reinforced composite materials are utilized in many products in industry today, especially the plastics industry, and have great potential for future use. On recent development in reinforcement methods is the use of continuous-filament glass fibers in a winding process in conjunction with a thermosetting epoxy resin. This method has been used successfully in fabricating large-diameter rocket motor cases for missiles, such as the Polaris and Minuteman. Filament-wound cylinders of this type generally fall in the "thin-walled" category and can be analyzed by present theory. Similar future applications of filament-wound cylinders as thick-walled pressure vessels have been proposed, but present theory is inadequate for proper design. The inadequacy is due to the "plain-strain" assumption whereby the overall length of the cylinder is assumed unchanged by the loads. For a thick-walled cylinder of uniform material, the plane strain assumption is unrestrictive since longitudinal stress is independent of radial and tangential stress. ...