Stability of graphite/epoxy structures with arbitrary symmetrical laminates

This paper is concerned with compression testing of thin-walled graphite/epoxy structures and the development of empirical stability methods of analysis. The laminates of the structures tested were T-300/5208 graphite/epoxy with arbitrary, symmetrical stacking sequences. Crippling tests were performed on flat plates to generate no-edge-free and one-edge-free empirical crippling curves for use in buckling analysis of thin-walled graphite/epoxy short columns. Crippling tests of square tubes confirmed correlation with flat plates. Short-column tests of similar square tubes and tests of lsection members substantiated use of the Johnson short-column method. Ultimate compression tests were performed for most laminates, and nonlinear stress-strain curves were recorded in all cases.