Fibre Reinforced Polymer Columns in Axial Compression

Abstract

AbstractThis chapter focuses on the mechanical performance of fibre reinforced polymer (FRP) columns with square hollow sections (SHS) in axial compression. Width-thickness ratio (b/t) is an important geometric parameter for the local buckling of plates and therefore also for such SHS columns. The effects of b/t on the failure modes and load-carrying capacities of pultruded glass fibre reinforced polymer (GFRP) SHS columns are investigated in this chapter. Two SHS with different b/t values of 10.7 and 15.9 respectively are examined under axial compression. Experimental results reveal that local buckling occurs in section B (b/t = 15.9) but not in section A (b/t = 10.7). From a theoretical analysis, a formulation of critical b/t values is established at the boundaries between the failure modes of such GFRP SHS columns under compression, considering the different boundary conditions of the SHS side plates. It is commonly understood that global buckling occurs in columns with higher non-dimensional slenderness λ. This is only true when the width-thickness ratio b/t is less than the derived critical value. Experimental results from this study and previous literature are consistent with the developed theoretical estimations of failure modes and load-carrying capacities for GFRP SHS columns, considering the effects of both non-dimensional slenderness, λ, and width-thickness ratio, b/t.