Effect of Material Property Variations on Slip Behavior of High-Strength Bolted Frictional GFRP Joints

In this study, high-strength bolted frictional joints applied to π-shaped GFRP members were investigated. The material properties of the GFRP members and their variability were evaluated, and the influence of this variability on the slip behavior of the high-strength bolted frictional GFRP joints was examined. From the material tests, the obtained tensile strength and tensile modulus were assessed for goodness-of-fit to normal, log-normal, and three-parameter Weibull distributions. The tensile strength conformed well to all three distributions, while the tensile modulus conformed only to the log-normal distribution. In the finite element analyses, the longitudinal elastic modulus, Poisson's ratio, and shear modulus were varied within a range of ±3σ. The results indicated that the displacement response, particularly the initial stiffness, was strongly affected by G12, while the reduction rate of bolt axial force during loading was influenced by E1. Although the variation in G12 caused a noticeable change in the initial stiffness, the influence of the material property variations on the bolt axial force reduction and analytical slip resistance was limited within the range of the present analytical conditions.