Frequency Changes in Thin Rectangular Plates due to Geometrical Discontinuities. Part II: Frequency Shift Interpretation

This paper, as part of a series dedicated to highlight the way how natural frequencies of plates change due to damage, presents results of numerical and experimental modal analysis made on thin rectangular plates clamped at all four lateral surfaces. These results where processed and the so-called relative frequency shift for thirty vibration modes determined. It was revealed the rules how the frequencies change by varying the damage geometry, and proved that these data can be used for damage identification. Finally, the results are compared with measurements, in order to demonstrate the validity of the theoretical considerations