Electronic Journal of Structural Engineering International
Abstract
This paper presents a plastic mechanism analysis for circular hollow section (CHS) tubes
strengthened using carbon fiber reinforced polymer (CFRP) deforming in an axi-symmetric (elephant foot)
collapse mode under large deformation axial loading. The collapse proceeded progressively by folding about
three concentrated hinge lines and hoop extension of the shell. An expression for the plastic collapse axial
load was obtained by equating the total energy absorbed in bending and extension to the external work carried
out during deformation of the tube. The newly derived mathematical model takes into account the contribution
of the CFRP towards energy absorption during collapse. Comparisons of the predicted instantaneous
post-buckling collapse loads with those obtained from experiments carried out elsewhere show good agreement