Multiscale strength prediction of fiber-reinforced polymer cables based on random strength distribution

The strength prediction of fiber-reinforced polymer (FRP) cables provides a non-destructive technique for evaluating the cable properties. In this study, a shear-lag model that assumes impregnated fiber bundle (IFB) and resin matrix as the basic elements is proposed and complemented in finite element (FE) models. By importing the strength distribution of IFB fitted from experiments, the effectiveness of the proposed model was validated for four types of basalt FRP single tendons. The simulated strength demonstrated high accuracy with an error of less than 6%, which was more reliable than conventional methods. The full-scale failure mechanism and damage process of FRP cable can be explained from the aspect of IFB element, which is different from filament-based models. The effect of fiber strength randomness and the contribution of sheared resin matrix could be quantified. Then, a multiscale evaluation of basalt FRP cable was carried out, and the different failure patterns of the tendon and cable were identified. Based on the other external data of carbon FRP cable, the simulated cable force was found to be in better agreement with experimental one, compared to directly taking a strength reduction on the total tendon force.