Study on self-sensing performance of CFRP modified by nano-materials based on steel beam test

In this paper, the mechanical and self-sensing properties of carbon fiber reinforced polymer (CFRP) reinforced steel beams under different parameters are systematically studied. By changing the length, number of layers of CFRP and the thickness of steel beams, the influence of various parameters on the mechanical properties of the reinforced structure was analyzed, and the self-sensing improvement effect of three types of carbon nanomaterials (CNM) modified CFRP reinforced structures was explored. The results show that CNF-graphene modified CFRP exhibits the best comprehensive performance, its stiffness is 19.5 % higher than that of the control group, and the peak value of resistance change rate under cyclic load is 0.002, which is significantly higher than that of CNF modification by 6.9 % and graphene modification by 4.6 %. Segmented continuous monitoring using hybrid CNM modified CFRP can accurately capture the details of structural deformation. Under different CFRP parameters, when the length of CFRP is less than 40 % of the span of steel beam and the number of CFRP layers is more than four layers, debonding occurs. The research results provide a theoretical basis for parameter optimization and intelligent monitoring of CFRP reinforced steel beams.