纤维缠绕角度对GFRP约束混凝土短柱轴压性能的影响

In order to investigate the influences of fiber angles (i.e., the angle between the fiber direction and the longitudinal axis of the specimen) on the axial compressive behavior of GFRP-confined concrete, an experimental study on GFRP-confined concrete stub column with ±45°, ±60°and ±80° fiber angles was carried out under axial compression. The fiber angle and the GFRP tube thickness were considered as important parameters to investigate their influences on the failure mode, load capacity and axial stress-strain curves of GFRP-confined concrete. Experimental results show that the fiber angle has significant influence on the hoop stiffness and the hoop rupture strain of GFRP tube; the confinement effect of GFRP tube decreases with the decrease of the absolute fiber angle; the peak stress of the confined concrete decreases with the decrease of the absolute fiber angle, but the ultimate strain of the confined concrete increases with the decrease of the absolute fiber angle; Teng et al.'s design-oriented model and Jiang et al.'s analysis-oriented model can provide reasonably accurate predictions for specimens with ±80° GFRP tube, slightly unconservative predictions for specimens with ±45° GFRP tube, but inaccurate predictions for specimens with ±60° GFRP tube.