Adaptive sandwich structures

A new adaptive sandwich structure is developed using the shear mode of piezo-electric materials. Through this study, it is shown that the sandwich construction offers many advantages over conventional surface-mounted actuation constructions. It is also demonstrated that the present adaptive sandwich structure and the surface-mounted actuation structure have different actuation characteristics. The fully-coupled electromechanical governing equations and associated boundary conditions for an adaptive sandwich plate are formulated using variational principles. A specific sandwich plate is studied using the Raleigh-Ritz method and finite element analysis. Static solutions of a cantilever sandwich beam and its corresponding surface-mounted counterpart are obtained based on the formulations. Stress distribution of the two types of adaptive beams are investigated. A comparative study of a sandwich beam with small piezoelectric patches and its corresponding surface-mounted beam is performed using finite element analysis. The effects of actuator length and location on actuation performance of the beams are studied. The stress distribution under mechanical and electrical loads are investigated for both the sandwich beam and the surface-mounted counterpart. Experiments on actuation and sensing performance of the sandwich beam are conducted and compared with finite element analysis