Sensor-Based Simulation of Displacement in Reinforced Concrete Bridge Columns Subjected to Seismic Events Using Bar–Slip Models

Sensing-based simulation of structures involves the integration of continuous sensor data into physics-based models to enable real-time structural prognosis. This study introduces a method to simulate global lateral displacement in reinforced concrete columns by incorporating flexural and bar–slip models based on locally measured strain data. The methodology is evaluated through an experimental program involving columns subjected to consecutive seismic events. The experiments employed fiber-optic Bragg grating (FBG) sensors installed on the concrete surface, reinforcing bars, and inside the concrete core for real-time and continuous monitoring of strains in the plastic hinge area. This provides additional insights into the strain distribution across the cross section of the reinforced concrete column during seismic events. Finite-element models of the reinforced concrete columns were developed in OpenSees to investigate the contribution of bar slip in the lateral tip displacements of the column. The outcomes from the pushover and time-history analyses were compared with experimental findings, affirming the necessity of accounting for bar slip in computing lateral displacement. In the developed method, the measured strains were utilized to calculate lateral displacements by considering both flexural and bar–slip components. Flexural displacement was computed based on the calculated curvatures at the bottom of the column by using strains measured by sensors attached to the concrete surface. Slip displacement was computed based on the developed bar–slip model that incorporates measured steel strains. The calculated displacements based on the proposed mechanics-based models by using strain sensor data were compared to the displacements directly measured by a displacement transducer. The results suggest that incorporating bond slip through the proposed method yields a close alignment between the calculated displacement and the directly measured values, particularly during high-amplitude cycles.