An algorithm for suppressing vibration induced noise in EMI-based structural health monitoring

Electromechanical impedance (EMI) technology is a non-destructive method used for structural health monitoring (SHM), with the advantage of being easy to implement and sensitive to early-stage damage. However, the reliability of EMI technology is significantly affected by environmental vibration, as the coupling between lead zirconate titanate (PZT) and structures can be casually disrupted by environmental vibration, leading to false alarm in SHM. To address this problem, based on the fact that the effect of environmental vibration on damage monitoring index is random and the effect of structural damage on damage monitoring index is irreversible, this paper proposes an improved EMI algorithm that combines the statistical principle and the reward-penalty mechanism (RPM). Experiments were conducted to identify the damage of an aluminum alloy cantilever beam in strong vibration environment, and the damage of the cantilever beam was successfully identified after several rounds of SHM. The experimental results confirmed the effectiveness of the improved EMI algorithm and extended the range of applications for EMI technology.