| The work of this paper aims to study and realize the application of piezoelectric sensors based on time reversal in structural health monitoring（SHM）of concrete.The goal of this work is to design a method for detecting concrete cracks.The goal of SHM is to conduct non-destructive assessment of concrete structures on a continuous basis.When it comes to installing such systems,large concrete structures,such as nuclear power stations or bridges,present challenges.Particularly when you want to detect or even locate minor damage.The discovery of piezoceramic materials along with recent advances in sensor/actuator technology based on time reversal method SHM technique in the field of damage identification and diagnostics.This study is based on the nonlinear finite element modelling（FEM）of concrete.Many parameters influencing reinforced concrete models are studied.A commercial software package ABAQUS and concrete damage plasticity model is used to model concrete beams.Also,the compression and tension uniaxial stress-strain relationships are used effectively and damage parameter curves of concrete materials in ABAQUS.A simple nonlinear model is used to verify the performance of the proposed constitutive model and damage model.The results of the analysis are promising.Piezoelectric sensors,two on the top of the beam and two on the bottom are attached with concrete beam and an electric potential difference is created amongst the higher and lower surfaces of the sensors.The time reversal method is used to monitor crack in beam and during this method,the sensor and actuator exchange their part when the time reversed signal is retransmitted from the initial sensor to the initial actuator.During the analysis it is very indistinct that a discontinuity is created due to crack and propagation of stress in piezoelectric sensor is affected after the application of voltage.Zero stress is observed around the vicinity of the crack whereas,propagation of the stress permits on the upper side of the crack while for non-cracked homogenous beam the stress distribution is almost uniform.Also,by Comparing the induced voltage in a cracked beam and without cracked beam,and the violation in the symmetry of the signal proves the existence of the crack. |
