Browsing by Author "Divijesh, P."

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Design, analysis and testing of flexurally amplified piezoactuator based active vibration isolation system for micromilling
(Bangladesh University of Engineering and Technology, 2020) Divijesh, P.; Rao, M.; Rao, R.; Ahmed, R.M.; Sushith, K.
Vibration is considered to be one of the limiting factors which affects precise measurements and surface finish of various mechanical components. Active Vibration Isolation is one such effective method which reduces the unwanted vibrations in any mechanical systems in a wide range of frequencies. This paper presents the design, analysis and testing of an active vibration isolation system based on Flexurally Amplified Piezo actuators (FAP1 and FAP2). The proposed set up aims at obtaining 180° out of phase displacement signal to the generated displacement signal using FAPs thereby minimising vibrations at the isolation platform. The maximum displacements of FAP1 and FAP2 obtained for 0-150V sinusoidal peak to peak amplitude at 1Hz frequency was found to be 810?m and 780?m respectively. The experimental displacements obtained were compared with simulated displacements using Forward Bouc-Wen hysteresis model and found very well agreed with each other within 1% error. An attempt has been made to estimate the voltage required for obtaining any desired displacement of FAPs using Inverse Bouc-Wen model through Simulink. The experimental displacements for the corresponding estimated voltages were obtained for FAPs. Finally, the proposed set up was tested by actuating both FAP1 and FAP2 separately and simultaneously for 0-150V at 1Hz frequency and was found that the displacements obtained were 180° out of phase thereby minimizing vibrations at the isolation platform. © 2020 Zibeline International Publishing Sdn. Bhd.. All rights reserved.
Experimental investigations of structurally pre-stressed actuator based active vibration isolation system
(American Institute of Physics Inc. subs@aip.org, 2020) Divijesh, P.; Rao, M.; Rao, R.; Dheeraj; Sushith
Active Vibration Isolation is considered to be one of the most effective methods to reduce the undesirable vibrations generated in any mechanical system. Stacked piezoactuators are suitable actuators used for variety of applications such as micro and nano positioning applications because of their high stiffness and fast response. However in order to provide optimal preloading force to the stacked actuators for longer lifetime and better performance with dynamic applications these stack actuators are structurally pre-stressed. In the present work, an active vibration isolation system is designed and developed using two structurally pre-stressed actuators namely source actuator and isolator actuator where source actuator is used for generating vibrations and the isolator actuator to nullify the generated vibrations. Initially the transfer function of the MLA 10x10x20 stack actuator was identified using its known parameters and was modeled in MATLAB/ Simulink to estimate the simulated displacement for a particular voltage at different frequencies. The simulated displacements were then compared with experimental displacements for different frequencies and the results were plotted. The experimental displacements of both source actuator and isolator actuator were found at different frequencies and was compared with the simulated displacements for a particular voltage and the results were plotted. Finally active vibration isolation experiments were carried out using the proposed set up for a particular voltage at different frequencies and the percentage of vibration isolation achieved was also estimated. Â© 2020 Author(s).