An investigation into the buckling behaviour of hybrid fibre reinforced polymer-timber thin-walled C-section columns

Hybrid fibre reinforced polymer (FRP)-timber (HFT) thin-walled structural members are a novel technology developed recently as a sustainable alternative to thin-walled steel and aluminium structures. HFT structures are made by forming thin timber veneers and FRP laminates into efficient cross-sectional geometries. While existing studies have demonstrated the potential of HFT thin-walled members to be used as structural elements, a systematic study to investigate the behaviour of HFT thin-walled structures is yet to be carried out. This paper presents a study aimed at investigating the behaviour of HFT C-section columns under concentric axial loading. In total five HFT C-section specimens each from 700 mm to 2000 mm lengths were fabricated and tested. It was found that shorter HFT C-section columns failed due to local buckling while increase in length changed the failure mode to global buckling. Effect of GF orientation and density on load carrying capacity of the HFT C-section columns was investigated numerically. It was found that it's necessary to provide adequate GF volume in transverse to axis direction, but further increase in GF volume in transverse direction did not significantly increase the load carrying capacity. Increase in GF density in parallel to axis direction increased the load carrying capacity.