PSI - Issue 70

Arpit Singh et al. / Procedia Structural Integrity 70 (2025) 580–587

584

3.1. Test specimen: Beam A plain concrete beam (100 mm x 100 mm x 500 mm) was made using standard portland cement and natural materials, with standard mixing methods. 3.2. PZT sensor placement The PZT sensor is mounted on the specimen surface with high-strength epoxy adhesive for good mechanical coupling to provide accurate strain, vibration, or stress-induced deformation detection. After bonding, the sensor electrodes connect to an impedance analyzer to measure real-time changes in conductance and susceptance. The electrical responses directly relate to the mechanical stresses applied to the specimen, enabling dynamic structural health monitoring by the electromechanical impedance principle. 3.3. Signal application (LCR meter/signal generator) An LCR meter (IM3536) energizes the PZT sensor with a small AC voltage signal of 1V. The voltage signal is applied across the sensor at some specific frequency range. The mechanical deformation, like vibration, experienced by the specimen will cause an electric charge to be generated in the PZT sensor. Thus, the sensor response can be traced at various modes of vibration or resonant frequencies of the specimen by varying the frequency of the signal.

3.4. Data acquisition system (DAS)

The electrical signals from the PZT sensor are captured using LCR meter software in a computer/data acquisition system. This system continuously monitors the signal output; that is, real-time data is generated about the sensor response to structural changes.

Fig-2: LCR meter

Fig-3: Beam after controlled damage

3.5. External control damage To have real conditions, artificial controlled damage as external damages is imposed on the test sample. Cuts correspond to the cracking caused in an actual structure. The changes of these cuts are sensed mechanically.

3.6. Signal analysis

The frequency response of the sensor is analyzed by DA system techniques. The stiffness and damping in the frequency response are associated with structural damage, are analyzed and by using the combination from HIXON table given in Table 2, we calculate electrical parameter to mechanical parameter and on the basis of trend change of mechanical parameter we can identify the structure health by comparing healthy (baseline) signature of the structure. For example, the decreasing of the equivalent stiffness show the damage of the structure, thus requiring maintenance and subsequent repairs.