Parametric Estimation for RC Flexural Members Based on Distributed Long-Gauge Fiber Optic Sensors

Long-term monitoring on the degradation of concrete structures has been a major engineering concern in many parts of the world. On the basis of the distributed long-gauge fiber optic sensors recently developed at Ibaraki University, this paper is dedicated to proposing a method for parametric estimation of RC flexural members. Experimental investigations are first introduced to validate the ascendancy of the developed sensors over some traditional sensing techniques for health monitoring of a RC beam. A section fiber model with plane section assumption is then adopted to establish the correlations among loads, structural parameters, and structural macrostrain responses. Based on the assumption that all structural parameters within the gauge length of a long-gauge sensor are homogeneous in an average way, an idea of “dividing and ruling” is put forward by artificially dividing a member into several cells corresponding to the sensor gauge length and then treating each cell as a section fiber. From the view of long-term structural health monitoring, an integrated strategy is proposed to identify the structural parameters including curvature, crossing area of reinforcement, and average stiffness of RC flexural members. Experimental and analytical investigations on a RC beam are finally conducted to verify the feasibility and effectiveness of the proposed method.