Multi-physics field models of photostrictive unimorphs and heterogeneous bimorphs subjected to light illumination and mechanical loading

This paper presents novel constituent equations for photostrictive unimorphs and heterogeneous bimorphs by considering multi-physics fields. Although the formulation is conducted using the lead lanthanum zirconate titanate ceramics (PLZT) polarized in 0-3 direction subjected to light illumination and mechanical loading, the results may be extended to other photostrictive materials or degenerated to piezoelectric ceramics. In the present formulation, photo-induced electrical, thermal and mechanical fields in PLZT ceramics are studied first, and then one-dimensional opto-thermo-piezoelectric equations for 0-3 polarized PLZT and other photostrictive materials are discussed. On the basis of the photo-induced multi-physics equations, 0-3 polarized PLZT unimorphs and bimorphs are investigated and the associated constituent equations are derived. The numerical results calculated using the present formulations are then compared with those available in the literatures to validate the derived novel constituent equations.