Composites 33, 225-232, 2002
D.H. Pahr¹, F.G. Rammerstorfer¹, P. Rosenkranz², K. Humer² and H.W. Weber²
¹Institute of Lightweight Structures and Aerospace
TU Wien, Vienna, Austria
²Atomic Institute of the Austrian Universities, Vienna, Austria
Two experimental methods for determining the inter-laminar shear strength
(ILSS), are compared: the short-beam-shear (SBS) and the double-lap-shear (DLS)
Specimens with a constant ply angle for all layers are considered.
The experimental results show a significant difference (up to 50 percent) in
the obtained ILSS.
A finite element analysis shows that both test methods underestimate the real
ILSS and demonstrate that the standardized ILSS-evaluation procedures are more
or less valid for the SBS test, but require modifications in the case of the
Acoustic emission measurements and numerical investigations were performed to
determine the real ILSS from the DLS results.
The real ILSS cannot be obtained from the SBS test without an extended
It is, however, possible to determine bounds for the real ILSS from the