Volume 9,
Issue 6, 2000
Impact pf adhesively
Bonded Composite Joints with Edge Effect
I.R. Farrow*, K.Potter, A.Fisher, M.Kelly
Department of Aerospace Engineering, Bristol University,
Bristol, UK BS8 1TR, Tel +44 (0) 117 928 7704; fax +44 (0)117 925 1154; E-mail
address: ian.farrow@bristol.ac.uk
*Author to whom correspondence should be addressed
(Received 10/00 ; accepted 11/00)
ABSTRACT
A pilot project has been carried out to investigate the effect of
impact on single-lap bonded composite joints based on AS4-8552 laminates and Cybond
BR4535A adhesive. Low velocity impacts at an energy level sufficient to cause barely
visible impact damage, were conducted on single lap joint specimens at different joint
positions. Impact caused delaminations in the upper and lower laminates and localised
through-thickness cracking in the adhesive. Residual tensile joint strengths of the
impacted joint specimens with near-edge damage were reduced to approximately 50% of the
un-impacted value. Failure surface inspections revealed localised through-thickness
adhesive shear cracking as a governor of the original impact delamination pattern in the
laminates and laminate delamination as the cause of ultimate tensile failure.