Statistical modeling and reliability analysis of large-scale multi-tendon fiber-reinforced polymer cables

Abstract

In this study, the classic fiber bundle model is exploited in the statistical modeling of fiber-reinforced polymer (FRP) cables. Important features of large-scale multi-tendon FRP cable are considered including initial random slack, uneven tensile deformation among tendons, and other statistical mechanical properties of tendon. Aiming at the prediction of load-displacement relation and design of thousand-meter-scale FRP cables, a parametric study and reliability analysis are conducted, in which the relation of reliability index β of cable and safety factor γ of FRP material is emphasized. In four different types of FRP cables from previous studies, the simulated load-displacement curves are in good agreement with experimental ones. The random slack and non-uniform deformation of tendons are found to have significant impacts on cable capacity. For a 10,000 m-long cable, compared to the original strength of the tendon, the retention rate of strength in real FRP cable can vary from 0.26 to 0.82, depending on the scattering of tendon strength. The recommended γ is 3.0, 3.2, and 3.4 for target reliability index βT = 3.7, 4.2, and 4.7, respectively. Then, the limits of design parameters for large-scale FRP cables are calculated under a given reliability index.