Fatigue crack monitoring of riveted aluminium strap joints by Lamb wave analysis and acoustic emission measurement techniques

Application of the Piezoelectricity in an Active and Passive Health Monitoring System

“…Hence, wingbox skins were bolted onto a metallic substructure consisting of three metallic spars. The skins used were rectangular panels (1800*760 mm 2 ) with a thickness varying from 6 mm to 4 mm and they were made of 913C-HTA composite material. The lay-up and geometry and the material data are given in Appendix A and B, respectively.…”

“…Damages indexes were also developed using wavelet analysis and allowed to avoid false alarm, despite the false detection probability could not be measured. Finally, the goal of detecting damaging due to impacts in a complex structure with a minimum of transducers was achieved since only 9 transducers were used for a surface of 1800*380mm 2 . More work on the active monitoring and more precisely on the Lamb wave interaction with damage is now required in order to extract the information related to the severity of damage.…”

“…the detection of the Acoustic Emission (AE) energy that is generally released when the material is bent or cracks due to an external load (pressure, impact, temperature, etc…). This strategy needs permanent monitoring, in flight and on the ground as well [2][3][4]. The second strategy consists in detecting the damage itself by periodically checking the structural health.…”

Assessment of fatigue damage in solid plates through the ultrasonic Lamb wave approach

“…For ensuring the reliability and security of solid plate-like structures in service, it is of vital importance to develop an effective approach to assess fatigue-induced damage (especially in the early stages of fatigue life). Recent studies indicate that ultrasonic Lamb waves have shown great potential for structural health monitoring [1][2][3][4][5][6][7][8][9][10][11][12][13]. For a material having a plate-like configuration, the Lamb wave inspection technique has an attractive advantage that Lamb wave can possibly test the entire thickness of the material over a great distance.…”

Application of Piezoelectric Transducers in Structural Health Monitoring Techniques

“…Grondel [15] has optimized the SHM using Lamb waves for aeronautic structures by studying the adapted transducer to generate Lamb waves. Paget [16] has elaborated a technique to detect damage in composite materials.…”