Numerical analysis on design and application of cement-based sensor for structural health monitoring

This article simulates the stress state and strain compatibility of the sensor embedded into concrete member to provide theoretical support for design and application of cement-based sensor. The effect of sensor dimension, voltage electrode separation, and surface roughness on strain compatibility between the embedded sensor and the concrete surrounding it is analyzed. The optimally designed sensor is embedded into concrete for health monitoring, and its stress state is investigated. A modified method for the monitoring results is proposed by studying the effect of embedded location and small deflection angle of the sensor, strength grade of concrete, amplitudes, and types of load on stress/strain compatibility. The results show that the optimum dimension and voltage electrode separation of the sensor are 20 mm × 20 mm × 40 mm and 10 mm, respectively. The sensors are nearly subjected to a uniaxial stress state when the sensor is embedded in internal strain-homogeneous area of concrete structure. The presence of the sensor will affect the stress distribution of the concrete around the sensor. The strain of the sensor is approximately coordinated with that of concrete surrounding it. The monitoring results need to be modified with the correction coefficient of corresponding effect factors to ensure monitoring accuracy.