Lenoe, E. M.
Group leader, Avco Corp., Lowell, Mass.
Project monitor, Air Force Materials Laboratory, Ohio
Senior engineer, Avco Corp., Lowell, Mass.
Pages: 18 Published: Jan 1969
This paper describes the first phase of a program of critical evaluation and development of test standards for advanced composite materials. Emphasis is on flat laminates, and the work deals primarily with boron epoxy laminates fabricated using the 3M three-inch wide preimpregnated (prepreg) tape system. The results of approximately 1800 experiments are reported, and specific recommendations concerning specimen geometries and testing techniques are presented. Four types of experiments were investigated, namely, tension, compression, flexure, and shear tests. Tension test variables examined were ply thickness, orientation of reinforcement, gage length and width, type of grip, specimen edge finish, loading rate, specimen alignment, and method of strain measurement. In compression testing, the controlling features investigated were number of plies, specimen width and length, unsupported gage length and end cap, and specimen cross-sectional geometry. The flexural experiments considered the effects of orientation of reinforcement, number of plies, load contact radii, span and type, and spacing of loads. Interlaminar (short-beam) shear tests were considered, and the effects of span-to-depth ratio were determined. Torsion test data for rods of boron epoxy materials are discussed also with regard to the observed shear response of the resin system.
composite materials, boron, epoxy laminates, testing, tension, compression, flexure, shear, evaluation, tests
Paper ID: STP49811S