Analytical design model for a piezo-composite unimorph actuator and its verification using lightweight piezo-composite curved actuators

Abstract

This paper describes an analytical design model for a layered piezo-composite unimorph actuator and its numerical and experimental verification using a LIPCA (lightweight piezo-composite curved actuator) that is lighter than other conventional piezo-composite type actuators. The LIPCA is composed of top fiber composite layers with high modulus and low CTE (coefficient of thermal expansion), a middle PZT ceramic wafer, and base layers with low modulus and high CTE. The advantages of the LIPCA design are to replace the heavy metal layer of THUNDER by lightweight fiber-reinforced plastic layers without compromising the generation of high force and large displacement and to have design flexibility by selecting the fiber direction and the number of prepreg layers. In addition to the lightweight advantage and design flexibility, the proposed device can be manufactured without adhesive layers when we use a resin prepreg system. A piezo-actuation model for a laminate with piezo-electric material layers and fiber composite layers is proposed to predict the curvature and residual stress of the LIPCA. To predict the actuation displacement of the LIPCA with curvature, a finite element analysis method using the proposed piezo-actuation model is introduced. The predicted deformations are in good agreement with the experimental ones.

A geometrically non-linear piezoelectric solid shell element based on a mixed multi-field variational formulation

“…Furthermore we discuss the impact of the enhanced assumed gradient (EAG) interpolation (43) to the patch test. In detail three element formulations are considered, which differ in the interpolation Eq.…”

“…In detail three element formulations are considered, which differ in the interpolation Eq. (43) and are summarized in Tab. 1.…”

“…In this example a lightweight piezoelectric composite curved actuator (LIPCA) is analyzed with the proposed geometrically nonlinear solid shell element; the results are compared to experimental data published in [43]. LIPCAs are manufactured as composites with different layers depending on the type of the LIPCA.…”

“…6. The material data for the two epoxy materials and the material properties of the PZT-5A piezoelectric ceramic, see [43], are listed in Tab. 8; values in thickness direction are assumed.…”

“…8; values in thickness direction are assumed. Table 8: Material properties and density ρ of the employed layers According to Yoon et al [43] the experimental setup is designed to simulate a simply supported boundary condition, which is shown in Fig. 6.…”