Compression strength of hollow sandwich columns with GFRP skins and a paulownia wood core

This paper introduced a simple and innovative hollow sandwich columns with GFRP skins and a paulownia wood core (GSW columns), which were manufactured by vacuum assisted resin infusion process. Four full-scale GSW columns were fabricated and tested under axial compression loading to validate the effectiveness of this column. The ultimate axial load capacity, displacement ductility, failure mode and axial force distribution between GFRP skins and wood core were investigated. Meanwhile, the finite element analysis was conducted to extend to investigate the effects of wood density, GFRP skin thickness and hollow ratio on the axial strength which were not considered in the tests. The numerical results revealed that increasing GFRP skin thickness and decreasing the hollow ratio can enhance the ultimate axial load capacity of the columns. Furthermore, increasing the wood density can improve the initial stiffness significantly. The corresponding calculation formulae were also derived to predict the ultimate axial load capacity of sandwich columns.