Numerical and Statistical Analysis of the Influence of Damage and Temperature on EMI for Structural Health Monitoring

Structural health monitoring (SHM) is a process of implementing a system to monitor the structural condition of a structure and assess the structural health. SHM is used to detect damage, predict future performance, and monitor the overall structural health of a structure. Electromechanical impedance (EMI)-based SHM is a non-destructive evaluation (NDE) technique that can be used to detect damage in structures by measuring the changes in the electrical impedance of a piezoelectric transducer that is bonded to the structure. EMI has several advantages over other NDE techniques, including being a passive, local, and relatively inexpensive technique. However, one of the challenges of using EMI for structural health monitoring (SHM) is the effect of damage and temperature on the impedance of the piezoelectric transducer. As the damage and temperature changes, the impedance of the transducer will also change. This can make it difficult to detect small damage if the damage and temperature co-exist on the same structure (aluminum plate). This research presents a numerical and statistical study to investigate the effects of damage and temperature on EMI-based SHM. The numerical model uses ANSYS software to simulate an aluminum plate at different temperatures. The findings have shown that both damage and temperature have a significant effect on the impedance of the transducer. However, the study has also demonstrated that it is still possible to detect structural damage using EMI even under varying damage and temperature conditions. This underscores the robustness of EMI-based damage detection methodologies in practical applications.