DYMAT 2009 (2009) 449-455
DOI: 10.1051/dymat/2009064

High strain rate delamination of glass fibre reinforced polymers using a Hopkinson bar configured for spalling

R. Govender¹, L. Louca², A. Pullen² and G. Nurick<sup>2

1</sup>  Blast Impact and Survivability Research Unit (BISRU), Department of Mechanical Engineering, University of Cape Town, Private Bag X3, Rondebosch, Cape Town, 7701, South Africa, www.bisru.uct.ac.za
²  Department of Civil and Environmental Engineering, Skempton Building, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK

Published online: 15 September 2009

Abstract
A Hopkinson Pressure Bar (HPB) was configured to perform spall testing on a glass fibre reinforced polymer (GFRP). The GFRP was woven roving E-glass in a vinyl ester matrix (Derakane 8084). The specimens were cylinders aligned in the through thickness direction, in order to test the interlaminar tensile strength at elevated strain rates. This testing method has previously been applied to brittle materials such as ceramics and concrete – this is the first time it has been applied to composites. The spalling HPB method is attractive for composite testing as the specimens are simple cylinders and as no grips are used, a uniaxial stress state is ensured in the entire specimen. The tests were successful in determining the initiating stress for interlaminar tensile failure. The strain rate during the tensile portion of the tests was approximately 1.8×10² s⁻¹. Formation of partial cracks, which exhibit significant residual strength, indicates that the interlaminar behaviour is not perfectly brittle.

© EDP Sciences 2009