Folded fabrication of FRP-timber thin-walled beams with novel non-uniform cross-sections

An interdisciplinary research collaboration at the University of Queensland (UQ) has pioneered an innovative cured-in-place manufacturing process that enables new material and geometric possibilities in the design of hybrid FRP-timber thin-walled structures. The cured-in-place process utilises a flat, fibre-reinforced polymer (FRP) embedded with a fast-curing 'panel' resin and a slow-curing 'fold-line' resin. The panel region is bonded to a timber segment that enables complex thin-walled profiles to be easily formed by folding cured panel regions about partiallycured fold-line regions. This paper explores application of this folded fabrication technique to the manufacture of novel origami-inspired beams with non-uniform cross-sections. An experimental analysis is conducted comparing a typical rectangular hollow section and an equivalent curved-crease origami spindle beam. The spindle beam is seen to have a substantial increase in strength and stiffness compared to the rectangular hollow section, but exhibits several complex failure modes including local buckling and delamination.