Low-and high-cycle fatigue behavior of FRCM composites

This paper describes methods, procedures, and results of cyclic loading tensile tests of a PBO FRCM composite. The main objective of the research is the evaluation of the effect of low-and high-cycle fatigue on the composite tensile properties, namely the tensile strength, ultimate tensile strain, and slope of the stress–strain curve. To this end, low-and high-cycle fatigue tests and post-fatigue tests were performed to study the composite behavior when subjected to cyclic loading and after being subjected to a different number of cycles. The results showed that the mean stress and amplitude of fatigue cycles affect the specimen behavior and mode of failure. In high-cycle fatigue tests, failure occurred due to progressive fiber filaments rupture. In low-cycle fatigue, the stress–strain response and failure mode were similar to those observed in quasi-static tensile tests. The results obtained provide important information on the fatigue behavior of PBO FRCM coupons, showing the need for further studies to better understand the behavior of existing concrete and masonry members strengthened with FRCM composites and subjected to cyclic loading.