Laser-scanning vibrometry for the investigation of sound generation and propagation

The paper describes how with one identical method the surface of a vibrating structure as well as the emitted acoustic sound field in air as well as the internal mechanical stress sigma(t) in the vibrating structure can be investigated and visualised. This unique capability opens new possibilities for improving and optimising the development of effective long-term stable sound transducers with optimised emission characteristics. Furthermore, the method can be used for investigating the internal stress of models of dynamically stressed mechanical structures. The simultaneous visualisation of vibrating surfaces, internal stress sigma(t) and emitted sound contributes to a better understanding of the behaviour of complex dynamically excited structures.