From 4-7 July 2022, SUSTAINair partner JKU took part in the EWSHM 2022, the 10th meeting of the international Structural Health Monitoring (SHM) community, to share new ideas and findings from their ongoing research on novel approaches to SHM applications for condition-based damage diagnostics in aircraft.
SUSTAINair contributes with presentation & paper to EWSHM
During their intervention at the EWSHM, JKU lead researchers Christoph Kralovec and Martin Schagerl firstly presented the project goals and main circular aviation research topics pursued by SUSTAINair.
Kralovec and Schagerl then presented the findings of their paper “Identification of Contact Acoustic Nonlinearities of Subsurface Cracks Located at Free-Edges”, which have been also included in the conference proceedings of this 10th edition of the EWSHM.
Nonlinear features could be crucial for damage detection
In their presentation at the EWSHM 2022, it was shown that overlap debonding was the initial failure mode of the considered hybrid Single-Lap Shear (SLS) joint. Simulation results further demonstrate the sensitivity of the vibration-based electromechanical impedance SHM method to this damage mode. The simulation results suggest also the existence of nonlinear features in the dynamic response of the debonded SLS joint.
According to Kralovec and Schagerl, the nonlinear features may be used as additional and very valuable information (additionally to linear response, which is typically used) for the evaluation of damage detection, quantification, and typification.
Preliminary SHM findings of JKU require further investigations
Additionally, Kralovec and Schagerl’s article investigated the nonlinear dynamic response of an aluminum beam with a subsurface crack located at the free edge to a harmonic excitation by a piezoelectric transducer, by means of scanning laser Doppler vibrometry.
The aluminum beam with crack represents a strongly simplified overlap debonded SLS specimen. These first results by SUSTAINair JKU researchers demonstrate the presence of the expected nonlinear behavior, and validate the applied method for identification of nonlinear dynamics despite distorted excitation, thereby enabling future research on more complex components.
Future research by Kralovec, Schagerl and the SUSTAINair JKU team shall now investigate the existence of the found nonlinear behavior and its application for SHM at the hybrid SLS specimen.
Find out more about JKU's contribution to the EWSHM 2022
The abstract of Kralovec and Schagerl’s paper “Identification of Contact Acoustic Nonlinearities of Subsurface Cracks Located at Free-Edges” is available online here since 19 June 2022. The conference proceedings of the EWSHM 2022 are available on the page of publisher Springer Cham. Disclaimer: these publications are not available through open access, and have not undergone a peer-review procedure that is equivalent to the peer-review procedure undertaken in peer-reviewed scientific journals.