PIEZOELECTRIC ACTUATION AND SENSING MECHANISMS - CLOSED FORM SOLUTIONS

摘要

The paper presents a parametric investigation of piezolaminated composite beams, with either surface mounted or shears actuator/sensor mechanisms. The actuator/sensor is either continuous or in the form of patches. The three-coupled equations of motion of a general non-symmetric piezolaminated composite beam subjected to axial and lateral tractions with the new (shear) and the traditional (surface mounted) actuation/sensing mechanisms are derived and solved for the static case. The displacement field is based on a first order shear deformation theory. It is assumed that the piezoelectric layers are perfectly glued to the carrying structure and the thickness of the adhesive can be neglected. Closed form solutions for the bending angle, the axial and lateral displacements, as well as for the voltage developed on the electrodes of the piezoelectric material along the beam are presented for various configurations of patches, and boundary conditions under mechanical and/or electric loads. The effects of actuator location and number of patches on actuator performance of the structure are studied. The performances of the shear type patch are compared with the traditional, surface mounted patch, for the actuation and sensing modes. It seems that in the actuation mode, the surface mounted type patch has a great efficiency compared with the shear type. However, by changing the dimensions of the beam to a short and “stubby” one, the efficiency of the shear piezoceramics becomes larger than the efficiency of the surface mounted piezoceramics. For the sensing mode, the shear type piezoelectric patch might provide a greater output as compared with the surface mounted type one, for certain loading cases.