Portfolio Project

• Energy Harvesting & Bandgap Formation in Meta-structures using Piezoelectric Materials

• Apr 2018 - Jul 2018

In this project, I have assessed the formation of Bandgap & Energy Harvesting in Meta structures, specifically, a Cantilever beam had been considered for the assessment. That is, for analysis of cantilever beam with resonators attached to the beam utilizing springs are considered at the initial stage for the formation of bandgap at the desired range of frequencies (Lumped resonators are considered initially). Governing equations for the Meta-system has been derived and combined to form an electromechanical system. After creating a bandgap formation at a desired range of frequencies, Piezoelectric material is glued onto the resonators to harvest energy but before employing piezoelectric layer on the resonators, equivalent distributed resonators are modelled which is performed by using the Rayleigh method of approximation for one-degree of freedom system. On further, Energy harvesting is simulated for a range of electrical load considering into account of previously set bandwidth of bandgap. The effect of shunt circuitry on bandgap formation is studied. Lastly, Comparisons for various system parameters are simulated. Optimality of the overall system is performed by considering the safety of the main beam (Plain structure), attenuation of vibrations along power absorption. Realization with commercially available material is performed, practical limitations are discussed. Combining Mechanical-electrical governing equations for the overall system is performed for an Euler-Bernoulli based beam. Analysis of a coupled system is conducted by the Modal approach. Frequency response of the system for various system parameters such as Vibration response of main structure and resonators, Electrical parametric responses such as voltage, current and power generation has been studied by considering different Admittance operators such as Resistor, Capacitor, Inductor and a combination of Resistor-Inductor, resistor-capacitor etc in a given range of frequencies. Additionally, conversion of AC-DC conversion for constant power absorption is implemented. And the effect of energy harvesting directly from the main structure and from both Resonators and the main structure is studied. Comparison of energy harvesting between various combinations is performed. Effects of various system parameters such as geometric, material on electrical power generation and bandgap formation have been studied for various electrical loads. And Optimal conditions for geometry, electrical load for power generation and bandgap formation are studied along with a realization. Appropriate conclusions have been made by considering all the above parameters into consideration. The effect of several unit cells on optimal system parameters such as electrical load, bandgap formation, Power generation is studied. Realizing these optimal solutions with commercially available products such as commercial piezo patches, existing values for an electrical load such as inductance, capacitance and resistance are studied. The final part of the analysis is the structural integrity of the main beam under dynamic behaviour is performed by using “Strain based approach due to fatigue”. Appropriate conclusions have been made by taking bandgap formation, power generation and structural integrity into consideration.