Modal Parameters Identification and Modeshapes Reconstruction for CFRP Panels with Operational Modal Analysis Performed with Digital Image Correlation

This paper explores the possibility of implementing a CFRP panel defect identification procedure by performing an Operational Modal Analysis using a contactless procedure. Traditional operational and experimental modal analysis techniques imply using accelerometers mounted directly on the structure and excitations provided directly on the structure with instrumented hammers or shakers. These components introduce non-negligible impacts in the case of highly flexible structures with intrinsic low stiffness. The project’s main idea is to provide the CFRP panel with a broadband white noise excitation employing a conic loudspeaker. The response of the structure will be measured with Digital Image Correlation techniques. To extract modal parameters and reconstruct structure mode shapes, we have developed software that runs Operational Modal Analysis algorithms based on the SSI-COV method for system identification. Given the setup above, it will be possible to carry out operational modal analysis with a noninvasive technique, allowing surface deformations to be measured without altering the structural integrity or the performance of the object under examination.