Non-destructive and non-contact materials research

Fiber-reinforced composites are becoming increasingly important in component manufacturing in order to reduce weight and achieve high specific stiffness. Examples are the production of aircraft wings in aviation or car body parts in the automotive industry. Delamination or cracks must be localized in time during production or during maintenance checks to avoid premature material fatigue. When thin-walled fiber composite plates are excited at high frequency, for example by piezoelectric elements, Lamb waves (short-wave surface waves) are generated, among other things. These interact with imperfections in the material, causing inhomogeneities in the wave propagation or local resonances (local defect resonance - LDR).

Laser Doppler vibrometers of the Optomet Scan series can detect the in-phase propagation of the waves at each measuring point on the material surface and thus visualize defects in the material that are not visible to the naked eye. The internal signal generator can create any signal shapes that can be used to excite the components, such as pulses or frequency sweeps. The OptoSCAN software is used to carry out the entire measurement process, from setting up the measurement channels and defining the measurement points to visualizing and analyzing the measurement data in the frequency and time domains. With the help of the export function, the data can be exported in standard formats, such as UFF, HDF5 and mat-files (MATLAB), and thus further processed.