Journal Published Online: 31 January 2014
Volume 3, Issue 3

Internal Notched Flexure (INF) Test for Measurement of Mode II Interlaminar Fracture Toughness of Fiber Composites

CODEN: MPCACD

Abstract

A revised analysis to derive the expression for the mode II interlaminar fracture toughness of fiber-reinforced polymers from internal notched flexure (INF) testing in small deformation is presented here. The approach adopted for the derivation takes into account the interlaminar shear load in the overhanging section outside the span. This improves the prediction accuracy for the initial specimen compliance, as evident from a finite element (FE) model of the INF specimen. The FE model also suggests that extensive damage develops at the crack tip before the delamination growth. Therefore, rather than using the physical crack length to calculate the interlaminar fracture toughness, one should use the effective crack length, which can be determined based on the measured specimen stiffness from experimental testing. With that, the analytical expression yields an inerlaminar fracture toughness that is consistent with the input value for the cohesive elements of the FE model.

Author Information

Belay, Tsegay
Dept. of Mechanical Engineering, Univ. of Alberta, Edmonton, CA
Jar, P.-Y.
Dept. of Mechanical Engineering, Univ. of Alberta, Edmonton, CA
Cheng, J.-J.
Dept. of Civil & Environmental Engineering, Univ. of Alberta, Edmonton, CA
Pages: 23
Price: $25.00
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Details
Stock #: MPC20130034
ISSN: 2165-3992
DOI: 10.1520/MPC20130034