COMPUTATIONAL MODELLING OF THE LAYERED PIEZOELECTRIC COMPOSITES AND ANALYSIS OF THEIR ELECTRO-MECHANICAL RESPONSE UPON HARMONIC VIBRATIONS
Keywords:ceramic laminate, piezoelectricity, analytical model, FEM, Ansys, classical laminate theory, vibrations of beams, Hamilton’s variational principle, weight functions
Currently, a generation of electric power from alternative sources of energy, especially from ambient vibrations, is becoming a very hot topic. Devices converting mechanical energy into an electrical one are called energy harvesters and are often based on the piezoelectric phenomenon. For the optimal adjustment of such an energy converter in the given application, it is necessary to have its computational model, which is able to describe all key aspects of its operation. Thus, this work focuses on the development of such a complex computational tool, which is able to globally describe the electromechanical response of the studied piezoelectric harvester operating in the form of a cantilever multilayer ceramic beam with piezoelectric layers. Such a multilayer structure is subjected to a kinematic excitation during its operation and also contains thermal residual stresses coming from the manufacturing process. The derived computational model utilizes the classical laminate theory to determine the static electromechanical response of the structure. Hamilton’s variational principle and the theory of beam vibrations were employed to obtain electromechanical response of the structure upon steady-state vibrations. The complex computational model is also capable of estimating the apparent fracture toughness of a given multilayer structure using the weight function method. The output of derived computational model is validated with FE simulations and available experimental results. This master’s thesis also presents an application of the derived computational model in the optimization of a particular multilayer beam to obtain
maximal electrical power output and to maximize its resistance to surface crack propagation and a potential brittle fracture. This goal is achieved by means of a suitable adjustment of thermal residual stresses in particular layers of the considered structure (controlled by used materials and by thicknesses of particular layers). Keywords ceramic laminate, piezoelectricity, analytical model, FEM, Ansys, classical laminate theory, vibrations of beams, Hamilton’s variational principle, weight functions.
How to Cite
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.