Browsing by Author "Sushith, K."

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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.
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    Development of piezoactuator based rotary tool feeding system for micro-EDM
    (Elsevier Ltd, 2022) Venugopal, T.R.; Rao, M.; Rao, R.; Sushith, K.
    Micro Electrical Discharge Machining (micro-EDM) is widely employed for the fabrication of component parts used in Micro Electro Mechanical System (MEMS) devices and many other applications. Spark gap, being a critical process parameter in micro-EDM, must be maintained at optimum length for stable machining. To meet this critical requirement, the tool feeding system employed in micro-EDM must be capable of feeding the tool electrode adaptively to maintain the optimum spark gap. This paper proposes to develop a Flexurally Amplified Piezoactuator based rotary tool feeding system for micro-EDM. Hysteresis behavior of the piezoactuated tool feeding system is modeled using Maxwell's hysteresis model. Model based tool feed control experiments were conducted for different feed displacements ranging from 100 μm to 600 μm and spindle rotational speeds from 400 rpm to 1800 rpm. From the experimental results it is observed that the developed rotary tool feeding system performs with an error less than 1% for larger feed displacements at higher spindle speeds. Machining experiment with tool rotation enhanced blind hole depth by 29.21% compared to machining without tool rotation. [copyright information to be updated in production process]. © 2022 Elsevier Ltd. All rights reserved.