Size effect on tensile strength of parallel CFRP wire stay cable

The paper studies the size effect on the tensile strength of parallel carbon fiber reinforced polymer (CFRP) wire stay cable in the macroscale. First, an asymptotic weakest-link Weibull model that incorporates a statistical length effect for the tensile strength of longitudinal composites is proposed in this research. For the proposed model, the weakest-link effect gradually becomes dominant and causes a decrease in strength that increases along the length of the longitudinal elements. The asymptotic threshold length Lρ on the strength analysis can be evaluated by the asymptotic weakest-link Weibull model. The strength data of single carbon fibers and impregnated bundles with different lengths obtained by previous studies are employed to validate the proposed model and the log-likelihood ratio test and the Bayesian information criterion (BIC) are used as the criteria for the validation of the proposed model. The tensile strengths of CFRP wires with different lengths are obtained and analyzed by using the proposed model, and the results obtained from the random strength field model proposed by Vořechovský and Chudoba are illustrated and discussed in detail. Finally, the actual strengths of two parallel CFRP wire cables are compared with the simulated results to illustrate the Daniels' effect on the strengths of parallel CFRP wire cables. To evaluate the strengths of parallel CFRP wire stay cables, the length effect and Daniels' effect should be considered in the design of the CFRP cables to ensure safety and reliability.