Research On Safety Evaluation And Fuzzy-Random Reliability Of Smart CFRP-Strengthened RC Beams

For important structure and infrastructure of civil engineering, it is inevitable that the integrated effects of various factors lead to the cumulating of damage and the attenuation of resistance of structure. The loss and the influence on the society are tremendous if disaster and accident occur. To prevent the accident, on one hand, the structure need to be reinforced to extend its life, on the other hand, the structure need to be monitored and evaluated by non-destructive method. The"Smart"CFRP is manufactured with CFRP and FBG sensors in this project. Retrofitting large-scale civil engineer structure with the intelligent CFRP not only can realize the material performance integration and structural material functional, but also can meet the requirement of non-destructive monitoring. The main contents include:Primary experimental research of"smart"CFRP in engineering application is completed. The"smart"CFRP is fabricated by curing FBG sensors in CFRP. Experiments on the influence of optical fiber's diameter, coating, plying direction and embedment numbers on mechanical properties of CFRP, and optical fiber's light-loss were carried out to study compatible properties of FBGS embedded in CFRP. The interface transferring mechanism of FBG strain sensors and error modification have been studied. The equations of multi-layer interface transferring and error modification are derived. Interface-transferring properties of FBGS embedded in CFRP were analyzed in theory. The strains of CFRP test specimen during tensile and flexural loading were measured by strain gauge and FBGS simultaneously. The strains measured by both methods were compared, and the strain sensing properties of FBGS were calibrated by using strain gauge.The flexural failure tests of"smart"CFRP strengthened RC beams were finished. 9 pieces of RC test beams were fabricated, the FBG sensors and strain gauges were mounted in the tensile steel, compress concrete and CFRP of the tested beams. Through the flexural failure tests, it is show that the measured results of FBG sensor and strain gauge are nearly same.According to the different working condition of cross-sectional failure mode and peeling failure mode for CFRP strengthened RC beams, the ultimate...