Circular
hollow sections (CHS) have been widely employed in structural and energy
absorbing applications. Due
to greater strength and ductility requirements, it
may result in very thin-walled steel sections that are susceptible to local
buckling. The use of new materials in the form of carbon fibre reinforced
polymer (CFRP) sheets has been increasingly applied with great advantage in
strengthening of existing
structures today. Furthermore, CFRP may also be
applied to minimise the effects of local buckling of thin-walled steel tubes.
There are limited international design guidelines that cater for the use of FRP
in steel structures, and hence research is needed to provide engineers with a
design method to use this new material with safety and cost efficiency. This
paper presents an experimental study to assess the influence of slenderness on
the bending strength of thin-walled CHS steel tubes
strengthened with CFRP for
use in design. The effects of fibre orientations are also examined by having
both longitudinal and hoop wrappings of steel tubes. It has been proved that by
using CFRP in both the longitudinal and hoop orientations enhanced the capacity
of slender sections to behave as compact or non-compact sections. The study
shows that greater strength and ductility can be achieved in thin-walled
circular steel tubes strengthened with CFRP, thus the use of this innovative
material have potential for cost efficient design and in retrofitting steel
structures for strength and seismic enhancement.