STRUCTURAL HEALTH MONITORING OF STIFFENED PLATES USING GUIDED ULTRASONIC WAVES

The concept of using distributed arrays of permanently attached sensors for the long-term structural health monitoring of large plates has previously been demonstrated under laboratory conditions. Based on the scattering characteristics of the employed guided ultrasonic wave mode at typical defects, the influence of the signal processing parameters on the damage detection and localization accuracy is discussed. Problems employing this structural health monitoring concept can occur due to additional changes in the signal reflected at undamaged parts of the structure. For real technical structures reflections occur at structural features, which have been identified as safety-critical areas for the development of fatigue and corrosion damage. Results from laboratory experiments are Presented for the detection of crack-like defects (notch) at a welded stiffener on a large steel plate structure.