Experimental Study on Monitoring Steel Beam Local Corrosion Based on EMI Technique

The corrosion of the steel structure not only causes the economic losses, but also poses a threat to the safety of the structure. The steel structure corrosion form is divided into uniform corrosion and local corrosion. Lead zirconate titanate (PZT) as a smart material was widely used in structural health monitoring (SHM) in recent years. For local corrosion damage in the form, a steel beam local corrosion monitoring experiments based on Electro-Mechanical Impedance (EMI) technique was designed. Marine environment was simulated and the steel beam local corrosion condition was designed firstly. Then the surface-mounted PZT transducer was used on the structure for long-term monitoring. The development process of corrosion and the admittance change was researched. The result shows that EMI technique is available to the beam local corrosion monitoring by analyzing the change rule of admittance signal and resonant frequency deviation ratio index with the steel beam corrosion.