Interlaminar fracture toughness of composites. II - Refinement of the edge delamination test and application to thermoplasticsThe mixed mode interlaminar fracture toughness, G(c), is obtained for the two thermoplastic matrices UDEL P1700 polysulfone and ULTEM polyetherimide by means of edge delamination tensile (EDT) tests on unnotched, eleven-ply graphite fiber reinforced composite specimens. A novel method is used to obtain the stiffness parameter employed in the closed form equation for the calculation of G(c), decreasing the number of stiffness measurements required and simplifying the calculations. The G(Ic) values from double cantilever beam (DCB) measurements on composites of the two thermoplastics were similar to each other, but slightly higher than the G(c) data obtained by EDT. Interfacial resin/fiber failures predominated in both the EDT and DCB tests.
Document ID
19840034349
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Johnston, N. J. (NASA Langley Research Center Hampton, VA, United States)
Obrien, T. K. (U.S. Army, Structures Laboratory, Hampton VA, United States)
Morris, D. H. (NASA Langley Research Center Hampton, VA, United States)
Simonds, R. A. (Virginia Polytechnic Institute and State University Blacksburg, VA, United States)