Abstract:
This paper reports a study of the performance of two forms of cutout and various
edge reinforcements in a composite C-section beam under static shear load.
Firstly, cutout shape effect on stress concentration was studied. This was
followed by a comparative study of a range of reinforcement doublers, which were
20 mm wide rings made of a steel alloy or composite laminate, or by a novel
fibre tow placement technique. The comparisons are made in terms of the stress
and strain reductions at a hot spot at the cutout edge. Good agreement between
the numerical and test results has been achieved for different cutout shapes and
reinforcements, and this study has demonstrated that the cutout induced stress
concentration can be reduced significantly by appropriate cutout shape and edge
reinforcements. The stress reduction magnitude is found to be strongly related
to the stiffness of the reinforcement rings. The diamond-shaped cutout and the
fibre tows reinforcement show clear advantages over the widely adapted circular
cutout and laminated ring reinforcement. These findings should contribute to
future design improvement of composite aircraft structures in similar shape and
loading conditions.
