Abstract: In recent years carbon fibre reinforced polymers (CFRPs) have become
some of the most important structural materials in the aerospace industry due
to their excellent stiffness and strength to weight ratios. The real-life
loading histories of aerospace composite components and structures involve the
generation of transient loads that can propagate as cyclic impacts. This
phenomenon is known as impact fatigue (IF). Such loads can cause various types
of damage in composites, including fibre breakage, transverse matrix cracking,
de-bonding between fibres and matrix and delamination, resulting in a reduction
of residual stiffness and a loss of functionality. The effects of IF are of major importance due its detrimental effect
on the performance and reliability of components and structures after
relatively few impacts and low force levels compared to those in a standard
fatigue regime. This study employs a unique testing system with the capability
of subjecting specimens to fully instrumented repetitive impact loading. The
main aim of this paper is to provide results elucidating the effect of IF on
the damage behaviour of CFRP specimens. A detailed damage analysis is
implemented utilising an X-ray micro computed tomography (CT) system.
