SEDL / STP / STP497-EB / STP27742S

Mechanical Behavior of Carbon/Carbon Filamentary Composites

Bert, CW
Consultantprofessor, Sandia LaboratoriesSchool of Aerospace, Mechanical and Nuclear Engineering, The University of Oklahoma, AlbuquerqueNorman, N.M.Okla.

Guess, TR
Staff member, Sandia Laboratories, Albuquerque, N.M.

Pages: 18    Published: Jan 1972

Download this paper for $25 PDF (236K)          View License Agreement
Abstract

The paper reports on uniaxial, biaxial, and shear loading tests on filament wound carbon/carbon composite tubes and rings. Circular cylindrical tubes were loaded in axial tension and compression, in hoop tension (by a pressurized bladder), and in combinations of these to obtain biaxial loading. Shear data were obtained primarily by means of out-of-plane loading of split rings, although limited data were also obtained from torsion tube tests. In reducing the test data to obtain the basic orthotropic elastic properties of a thin ply, it was found that the stiffness matrix was significantly unsymmetric, that is, the fundamental reciprocal relation involving the two in-plane Young's moduli and the two in-plane Poisson's ratios was violated. Thus, anisotropic elasticity and shell equations should be derived without assuming that symmetry holds. The implications of the results obtained are discussed in the light of thermodynamics, tests conducted by other investigators, and stress analysis.