Array technology for bending wave field analysis in constructions

In this paper it is shown that array technology is an essential tool for the quantitative analysis of bending wave fields in elastic, solid constructions. The advantages can be compared with those of array-based acoustic wave field analysis in free air as well as in enclosed spaces. In contrast to acoustic waves, bending waves are highly dispersive, i.e., their propagation velocity depends strongly on frequency. A convolution operation is introduced as a preprocessing step, removing the dispersion from the bending waves, such that their propagation properties become highly similar to that of acoustic waves. After this transformation, multidimensional acoustic wave field analysis methods can be successfully applied to bending wave fields, using the large technology portfolio in acoustic imaging. The new analysis method is applied to simulated bending wave fields and to real measurements on a rectangular steel plate. The proposed method is demonstrated on bending wave fields, but it can be applied to any type of dispersive wave phenomenon.