Determination of transverse shear strength through torsion testing

Conference · Wed Dec 31 04:00:00 EST 1997

OSTI ID:566495

Marcucelli, K T; Fish, J C ^[1]

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1. Lockheed Martin Skunk Works, Palmdale, CA (United States)

The in-plane characterization of composite materials is, in general, well understood and widely utilized throughout the aerospace industry. However, the use of composites in structural elements such as fuselage frames and rotorcraft flexbeams place large out-of-plane or through-the-thickness stresses for which there is little data. Efforts to determine the interlaminar shear strength of laminated composites have been hampered due to the nonlinear behavior of test specimens and the limitations of current analysis tools. An inexpensive rectangular torsion test specimen was designed to determine the interlaminar shear strength, s{sub 23}, of composite materials. Six different layups were fabricated of AS4/2220-3 carbon/epoxy unidirectional tape and tested in pure torsion. All of the specimens failed abruptly with well-defined shear cracks and exhibited linear load-deflection behavior. A quasi-three-dimensional (Q-3-D) finite element analysis was conducted on each of the specimen configurations to determine the interlaminar shear stress at failure. From this analysis, s{sub 23} was found to be 107 MPa for this material.

• OSTI ID: 566495
• Report Number(s): CONF-950569--
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
36 MATERIALS SCIENCE
AEROSPACE INDUSTRY
COMPOSITE MATERIALS
FAILURES
FINITE ELEMENT METHOD
MECHANICAL TESTS
SHEAR PROPERTIES
WEIGHT