This paper presents an experimental study to investigate the actuation performance of LIPCA (Lightweight Piezo-
Composite unimorph Actuator) with different loading cases. High value of the manufacturing-induced compressive
stress in PZT layer of LIPCA helps avoiding potential in-service failure, however, it may cause a reduction in strain due
to the induced piezoelectric effect. High compressive prestress makes the domains aligned and constrained
perpendicular to the stress direction. Consequently, fewer domains can be reoriented to contribute to polarization and
strain output. The unimorph actuator is thus designed and operated such that the compressive stress in piezoceramic
material is large enough to avoid failure in working condition but small enough to allow larger amount of non-180o
domain switching. To compensate the high designed compressive stress state in the piezoceramic attention should be
paid on the loading configuration when the actuator is working in-service condition. Experimental results show that the
actuator should be arranged in a manner such that the stress state within the PZT wafer is in as more tension as possible
to compensate the high compressive induced stress in the piezoceramic due to the manufacturing process.
In this study, we derive an analytical solution for the simply supported and multilayered unimorph piezoelectric composite actuator as a beam model under applied voltage and external mechanical loads. The obtained solutions based on Rayleigh-Ritz technique including thermal effect and piezo-mechanical coupling effect show their convenience in various problems with different loading and boundary conditions. The von-Karman nonlinear terms in strain-displacement relations is also taken into account in the model. As a numerical illustration, model of LIPCA-C3 (LIghtweight Piezo-Composite Actuator) is analyzed. The results are compared with finite element analysis and experiment ones. Discussion on the approach and suggestions for future research activities are also presented.