There exist many different mechanisms that induce changes into guided wave signals – generated and received by piezoceramic transducers – due to temperature variations.
- This includes the following effects:Changes of the plate stiffness affect the waves phase/group velocity at a given frequency, with a related variation in their measured time-of- flight.
- The plate in-plane expansion/contraction modifies the distance actuator-receiver causing a deviation in the time-of- flight of incoming and reflected modes.
- Temperature affects the dielectric permittivity and the piezoelectric coefficient of both actuator and receiver resulting in a pitch-catch voltage response sensitive to temperature variations.
Structural health monitoring often utilises sensor networks to monitor structures and reveal possible damage. Although damage detection methods based on guided ultrasonic waves have been investigated for many years, practical implementations are still limited. This is mainly due to problems associated with complex wave propagation physical mechanisms and operational/environmental effects that can seriously affect reliability. It is well known that temperature is one of the most important environmental conditions that can influence Lamb wave generation, propagation and sensing. Various aspects related to Lamb wave propagation under varying temperatures are discussed for example in [Ref. ].
- Acoustic Emission
- Multiscale modelling of nanocomposite materials
- Transducer design
- Nonlinear diffraction tomography