Ultrasonic and Electromagnetic Waves for Nondestructive Evaluation and Structural Health Monitoring

Use of ultrasonic and electromagnetic waves is continuously increasing for nondestructive evaluation (NDE) and structural health monitoring (SHM) in civil, aerospace, electrical, mechanical and bioengineering applications.Between bulk waves and guided waves, the latter is becoming more popular for NDE/SHM applications because the guided waves can propagate long distances and reach difficult to access regions. For inspcting porous and some non-porous materials in which the ultrasonic waves attenuate fast, electromagnetic waves such as THz (terahertz) radiations have been found to be very usful. Recent advances in ultrasonic and electromagnetic wave applications forNDE and SHM are discussed in this paper.