Broadband and High Frequency Piezoelectric Energy Harvesting System With Curved Panels For Passive Vibration Isolator

Abstract

In military aircrafts, random vibration occurs with high amplitude in broad frequency spectrum. High vibration profiles, which affecting electronic units, can cause fatigue over time and damage mechanics and electronic cards. Therefore, electronic units are integrated into aerial platforms via isolators to dampen vibration. The isolators significantly dampen the vibration exposure and significantly increase the life of the electronic units. Although they are mounted with isolators, it is of great importance to carry out instant health monitoring in order to prevent loosening and mechanical deformations that may cause vital problems. The energy needs of all electronic devices used in our daily lives are provided through various sources. Micro-electromechanical systems used in health monitoring and data transfer need their own energy source because they are used in hard-to-reach areas. For this reason, energy production methods from alternative sources are being investigated. Piezoelectric materials, which have a high energy production capacity in narrow spaces and can produce energy in a wide vibration frequency band without the need for another electrical source, are one step ahead for energy harvesting. Piezoelectric materials generate voltage through stresses caused by vibration on the surface to which they are attached. The voltage occurs harmonically at the vibration ii frequency, positively and negatively charged. When the generated voltage is connected to the circuit, it creates alternating current. After the energy is regulated, the battery/capacitor can charge and power electronic devices. As a result, systems can operate without the need for an additional energy source as long as there is vibration. In this thesis, energy harvesting from the piezoelectric material placed on the curved panels which are mounted on the isolators of the electronic unit subjected to military helicopter vibration profile. Curved panels on which piezoelectric patches are attached are mounted between the vibration source and the mass. Vibration acting on the isolator affected the curved panel with a higher profile than the vibration profile applied with phase difference and amplification. With the help of the natural frequencies of the curved panel, the piezoelectric materials were exposed to higher vibrations and produced high energy in a wider frequency band. Energy was produced by vibration, which is a completely undesirable energy encountered greatly on aerial platforms. Dummy mass was used as electronic unit and isolators was selected in line with the determined mass. In the selection of mass and isolators, care has been taken to ensure that the system is the only natural frequency in the frequency band of interest. Measurements were made by giving white noise to the system and its behavior was examined and verifications were carried out. Piezoelectric materials were adhered to the curved panel as 3 different patches. Curved panels and piezoelectric materials produced in the specified dimensions were driven by harmonic vibration and energy was produced. A finite element model of the system was created with the same dimensions with the help of Space Claim. The model was verified by performing finite element analysis using by Ansys. In the analysis study, the width, thickness and length of the piezoelectric patches were changed and the relative acceleration data measured in the isolator verification study was applied and sensitivity analysis was made.