Compressive behaviour of wood-filled GFRP square columns with lattice-web reinforcements

A novel wood-filled glass fibre-reinforced polymer (GFRP) square column (WGSC) with lattice-web reinforcements was proposed. Eight column specimens with varying numbers of face sheets and lattice webs and one control specimen were tested to investigate the compressive behaviour and failure mode of WGSCs. The experimental results reveal that all the specimens with lattice-web reinforcements failed due to crumpling of the face sheets and compressive damage in the core material. With increased number of lattice webs, the ultimate loads of the specimens increased, and pseudo-ductile behaviour was observed. Improvements were also found in the effective constraint and interfacial bonding performance of specimens with lattice-web reinforcements and affected by the number of face sheets. By introducing the concept of the constrained stiffness ratio, an analytical model was proposed for evaluating the ultimate load of the specimens based on Tsai-Wu strength criterion, and the results were consistent with the test data.