Dissipative heating and thermal fatigue life prediction for structures containing piezoactive layers

A coupled dynamic problem of thermo-electro-mechanics for a layered beam is formulated based on the Kirchhoff-Love hypotheses. In the case of harmonic loading, a simplified formulation is given using the single frequency approximation and the concept of complex moduli. As an example, the problem of forced vibration of a three-layer sandwich beam (aluminium alloy core covered with piezoelectric layers) with hinged ends is solved in order to investigate the accuracy and applicability of the approximate monoharmonic approach and to study the self-heating caused by the electromechanical losses in piezoactive layers and the mechanical losses in electrically passive metal layer. The thermal fatigue life was estimated assuming that the structure fails if the temperature exceeds the Curie point for piezoceramics.