Sandia Laboratories, Alburquerque, New Mex.
Pages: 28 Published: Jan 1974
An analysis of the response of a filament-wound spherical vessel to internal pressurization is presented. Based on a structural model of an elastic-plastic bladder inside a transversely isotropic elastic composite, analytic expressions for the stress, strain, and displacement fields are derived for pressures preceding, during, and after bladder yield. Equations for short-term composite failure pressures are predicted using maximum stress, maximum strain, and Norris-Ashkenazi failure criteria. Using the transversely isotropic model, laminate stiffnesses and strengths are computed from the micromechanically predicted lamina properties. The results are evaluated numerically for the PRD-49/epoxy, Thornel 400/epoxy, and Thornel 75S/epoxy systems, for a range of wall thicknesses. The Norris-Ashkenazi criterion is seen to give the most conservative failure predictions for the structure. The analysis emphasizes the need for reasonable radial compressive strengths and high filament volume fraction in obtaining a high-burst-pressure design.
composite materials, filament wound composites, pressure vessels, spherical shells, isotropy, laminates, analyzing, failure, criteria, epoxy resins, polymers
Paper ID: STP35512S