A topology optimization formulation for transient design of multi-entry laminated piezocomposite energy harvesting devices coupled with electrical circuit

Laminated piezocomposite energy harvesters (LAPEHs) aremultilayer arrangements of piezoelectric and nonpiezoelectric materials. Multiple materials and physics, and dynamic analysis need to be considered in their design. Usually these devices are designed for harmonic excitation; however, they are subjected to other types of excitations. Thus, a novel topology optimization formulation is developed for designing LAPEHs that considers a combination of harmonic and transient optimization problems with the aim of designing the so- called "multi-entry" devices in which the power generated is the same for different types of excitation. LAPEHs are modeled by the finite element method, and the material model used for the piezoelectric layer is based on penalization and polarization model who controls material distribution and corresponding polarization. To optimize the RLC circuit, a novel linear interpolation model of coupled electrical impedance is also introduced to consider different magnitudes of the coupled impedance. The topology optimization problem seeks to maximize the active power generated by the LAPEH at its RLC circuit, to minimize its response time measured as the slope of the power versus time curve, and to maximize its stiffness. Numerical examples are shown to illustrate the potential of the method.