Contactless detachment identification in frescoes utilizing a Scanning Laser Doppler Vibrometer
Abstract »This paper presents the results of an experimental study of the applicability of the laser Doppler vibrometer (LDV) as a potential detachment monitoring tool for choosing interventions necessary to stop the growth of pathological mechanisms of ancient frescoes. In our investigation, the use of the LDV has been integrated into a detachment monitoring technique by acquiring mechanical vibrations travelling in frescoes structures and activated by suitable excitation sources. The most important advantage of optical techniques is their non-invasiveness, so they could be installed on items consisted by delicate structures and precious surfaces. In our experiments, a scanning single beam LDV was utilized to acquire the vibration regarding both laboratory and real field frescoes tests. The results confirmed the effectiveness of the LDV and its integration into the proposed detachment index for detecting and locating single and multiple damages. Compared to other damage detection techniques the LDV, as a contactless optical measurement system, provided more satisfactory detection of single and multiple damages and can therefore be successfully utilized in health monitoring of frescoes. The analysis of the travelling wave velocity field of the observed frescoes surface and of its alterations allows the assessment of detachments, since the vibration modal parameters are affected by the system boundary conditions, i.e. the portion of analyzed fresco.
Biography: Professor Providakiis 's expertise is on Mechanics of materials, Smart Materials, structural Dynamics and damage identification. He has published more than 100 Research papers on Referee Journals and conference proceedings. http://users.isc.tuc.gr/~kprovidakis
Affiliation: Technical University of Crete School of Architecture GR-73100 CHANIA GreeceMousteraki, MariaMousteraki, Maria
Affiliation: Technical University of Crete School of Architecture CHANIA GreeceTsistrakis, StavrosTsistrakis, Stavros
Affiliation: Technical University of Crete School of Architecture CHANIA GreeceLiarakos, VagelisLiarakos, Vagelis
Affiliation: Technical University of Crete School of Architecture CHANIA Greece*Contact