Actuating characteristic of laminated PVDF actuators used on a beam with large deformation

Actuating characteristic of laminated PVDF actuator (LPA) partially covered on a beam is studied in this paper. Considering large deformation of the beam, coupled dynamic equations of the system are derived based on Hamilton principle. The formulas of nonlinear actuating forces are obtained and the parametric study is then conducted to evaluate the effects of geometric and physical properties of the actuator on its actuating forces. For a cantilever beam, the influences of the deformation, LPA location and PVDF layer number are discussed. The results show that the nonlinear deformation has no effect on the axial actuating force, but it induces pronounced actuating force in the transverse direction. The nonlinear actuating force is inversely proportional to the radius of local curvature, and it is linear with the number of LPA´s layers. The linear actuating force is the second-order polynomial function of the layer number. For a cantilever beam, the optimized location of the LPA is the fixed end for linear deformation. Whereas, the optimized position of the LPA is tip of the beam when large deformation occurred and the control force is afforded by nonlinear actuating force in the transverse direction.