Analysis of piezoelectric fiber composite beams

The collaboration of active piezoceramic fibers and passive matrix material compliments the dynamic actuation excellence of piezoelectrica with the tailorability of active and passive anisotropic properties as well as with the potential to realize flexible shaping and structural integration. This material composition with alignment of poling and electric field in fiber direction is examined on the micromechanics level to provide elastic and piezoelectric coefficients for the subsequent investigations. Thin layers of such a compound are joined with assistance of the classical lamination theory. The resulting active laminated composite is employed for the walls of a single-cell closed cross-section beam, which is modeled in Timoshenko fashion with supplementary torsional warping. The principle of virtual displacements is applied to a cantilever configuration and provides the natural boundary conditions and equations of motion. These are solved in conjunction with the stiffness and actuation properties for arbitrary constant and linear load conditions to obtain voltage dependent static displacements and rotations. Focusing on the beam twist different actuation schemes are examined and the interplay of stiffness characteristics and actuation efficiency is analyzed. The results are compared with the outcome of a finite element analysis using layered shell elements with the analogy of piezoelectric and thermal expansion.