Abstract:
To investigate the axial compressive performance of fiber reinforced polymer (FRP) composite-confined ultra-high performance concrete (UHPC) cylindrical specimens, the meso-scale finite element model was established in LS-DYNA and validated by the comparison of the experimental data. The formula of shear dilation parameter of K
&C model was proposed, which could accurately reflect the FRP composites confinement for UHPC. Based on the validated model, a parametric analysis was conducted to investigate the influence of FRP composite tube thickness, FRP composites fiber winding angle and steel fiber content. The results show that the model can not only capture the effect of random distributed steel fibers on the specimen stress distribution, but also accurately reflect the enhancement of strength and ductility of UHPC core subjected to FRP composite confinement. Good agreement is found in failure modes and stress-strain curves between simulation and experimental results. Parametric studies show that with the increase of FRP composite tubes thickness and FRP composite fiber winding angle, the strength and ductility of the FRP composite-confined UHPC specimens are significantly enhanced. An increase in steel fiber content can effectively restrain the inclined shear cracks in UHPC core, but has little effect on the strength and ductility of the specimens.