The Effect of Corrosion Intensity on Damage Metric in Impedance-Based Structural Health Monitoring of an Aluminum Cantilever Beam

Metal corrosion is the main phenomenon in different industries and destructive effects of this chemical phenomenon cause a lot of costs annually. While corrosion causes a little mass decrease in structure, brings about a dramatic reduction in mechanical strength and fatigue life of corroded materials. Hence, health monitoring of a structure can make aware of structure status at any time and prevents from harmful consequences. Structural Health Monitoring based on Electromechanical Impedance is one of the real-time monitoring techniques that could recognize damage on a structure by using an electromechanical coupling of piezoelectric materials, immediately. On the other hand, due to high frequency used in this method, small defects in the early stages will be detected. In this paper, Structural Health Monitoring based on Electromechanical Impedance was applied in an aluminum cantilever beam to recognize the corrosion and evaluate the capability of the Electromechanical Impedance method in detecting corrosion. Furthermore, the standard deviation of the mean square root has been chosen as the main metric, that it increases as the defect size increases. Afterwards, Experimental results were compared with health monitoring theory based on the Electromechanical Impedance and more energy method. Subsequently, the experimental results represent this method efficiency in the immediate monitoring of damage caused by corrosion in an aluminum cantilever beam. Besides, the possibility of pinpointing the defect by using this way has shown a good relationship between the place of damage and damage metric.