Opto-acoustical sensor to examine the structural integrity of complex systems

In this report we present the results of the analysis and experimental study of defect detection with Laser Doppler Vibrometry (LDV). The Non-Destructive Inspection (NDI) procedure is based on the vibrational mode evaluation for a test-object with specified defect parameters. To evaluate the procedure a clamped aluminum drum with radius R was selected as the test-object. The introduced defect was a thickness loss of 2.5%, 5.0% and 7.5% at the central part of the drum. The data from computational examination, based on finite element analysis, are compared with experimental data. Additionally, we present data from interrogation of a multilayer (carbon composite) element with preset defects in a specific layer and examples of corrosion detection. The experiments show that the proposed technique enables reliable defect detection, location, and quantification.