Case Study-Design and Testing of the Brunswick Graphite Composite Ring-Stiffened Thermoset Cylinder

Abstract

This paper discusses the design development of a four-foot (1.22 m) diameter graphite/epoxy composite cylindrical marine model. The cylinder was fabricated by Brunswick using an automated filament winding process and was nonautoclave cured in an oven. The paper reviews the details of the design/analysis approach and the assumed failure criteria using 2D solid axisymmetric finite element analyses with the ABAQUS code. Numerous design iterations were made to achieve a balanced design. The model is composed of 50% circumferential, 33% longitudinal, and 17% helical plies, and the ring (blade) stiffener is composed of all circumferential plies. This paper also reviews the assumed material properties used for the design and analysis, and the "asfabricated" material properties used to predict failure of the cylinder due to hydrostatic loading. The final design achieved a weight savings of 44% over an equivalent steel-stiffened cylinder. The cylindrical model was then subjected to a hydrostatic collapse test. A comparison of the test results and the failure prediction is also presented. This work was sponsored by the Maritime Systems Technology Office, Advanced Research Projects Agency.