Onur OzturkogluUmut YucelCihan KarademirErkan Durmazgezer2025-10-062024207634172076-341710.3390/app14219920https://www.scopus.com/inward/record.uri?eid=2-s2.0-85208583236&doi=10.3390%2Fapp14219920&partnerID=40&md5=0ed6b27334d9d513b1778d93edfc4c60https://gcris.yasar.edu.tr/handle/123456789/8145This paper aims to investigate the effect of glass fiber-reinforced polymer (GFRP) and carbon fiber-reinforced polymer (CFRP) strengthening materials on the static and dynamic behavior of reinforced concrete (R/C) beams subjected to progressive damage. Four identical beams each strengthened with either GFRP or CFRP are tested under a cyclic quasi-static loading pattern. Impact hammer tests are performed for undamaged states and various damage levels of the beams. The dynamic test data are analyzed using the Enhanced Frequency Domain Decomposition (EFDD) method to estimate the dynamic characteristics of the beams. In this context the first three vibration modes in both vertical and horizontal directions are considered. Strengthening is applied to both pre-damaged and undamaged beams enabling a comparison of their performance before and after the strengthening procedure. Beams strengthened with CFRP exhibit a higher load-bearing capacity and stiffness but also fail at lower displacement levels compared to those strengthened with GFRP which demonstrate more ductile behavior. Furthermore the modal frequency ratios indicate that the first vibration mode is more sensitive to damage than the second and third modes. This study highlights the effectiveness of both strengthening materials in enhancing the structural performance of both undamaged and damaged beams. © 2024 Elsevier B.V. All rights reserved.EnglishBeam Strengthening, Cfrp, Dynamic Behavior, Gfrp, Operational Modal Analysis, Pre-damaged, Progressive Damage, Quasi-static Loading, Carbon Fiber Reinforced Plastics, Concrete Beams And Girders, Elastomers, Fiber Reinforced Concrete, Glass Fiber Reinforced Plastics, Vibration Analysis, Beam Strengthening, Carbon Fibre Reinforced Polymer, Dynamic Behaviors, Fiber Reinforced Carbon, Glassfiber Reinforced Polymers (gfrp), Operational Modal Analysis, Pre-damaged, Progressive Damage, Quasi-static Loading, Static And Dynamic Behaviours, Glass FibersCarbon fiber reinforced plastics, Concrete beams and girders, Elastomers, Fiber reinforced concrete, Glass fiber reinforced plastics, Vibration analysis, Beam strengthening, Carbon fibre reinforced polymer, Dynamic behaviors, Fiber reinforced carbon, Glassfiber reinforced polymers (GFRP), Operational modal analysis, Pre-damaged, Progressive damage, Quasi-static loading, Static and dynamic behaviours, Glass fibersArticle