Faculty Publications

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Author: search.filters.author.Gangadharan, K.V.Subject: search.filters.subject.Vibrations (mechanical)

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Now showing 1 - 6 of 6
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    Statistical modeling of a magneto-rheological fluid damper using the design of experiments approach
    (2007) Shivaram, A.C.; Gangadharan, K.V.
    In this work, a through-rod-type magneto-rheological (MR) test damper has been designed and fabricated for experimental study. Various factors, such as the magnetic field strength, volume fraction of particles in the MR fluid, shearing gap between piston and cylinder, vibration frequency and amplitude, have been considered as input factors, and the root-mean-square (RMS) damping force as the output factor (response variable). These input factors are varied in two levels (low and high) during the initial phase of experimentation using 25 factorial design; the motivation is to identify the most influential factors. In the second phase of experimentation, the response surface method has been used to identify the modeling equation and to plot the response surfaces. Further, force versus displacement diagrams have been plotted at these factor levels; these give an insight into the damping behaviour of the MR damper. © IOP Publishing Ltd.
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    Active vibration control of a smart cantilever beam on general purpose operating system
    (Defense Scientific Information and Documentation Centre, 2013) Parameswaran, A.P.; Pai, A.B.; Tripathi, P.K.; Gangadharan, K.V.
    All mechanical systems suffer from undesirable vibrations during their operations. Their occurrence is uncontrollable as it depends on various factors. However, for efficient operation of the system, these vibrations have to be controlled within the specified limits. Light weight, rapid and multi-mode control of the vibrating structure is possible by the use of piezoelectric sensors and actuators and feedback control algorithms. In this paper, direct output feedback based active vibration control has been implemented on a cantilever beam using Lead Zirconate-Titanate (PZT) sensors and actuators. Three PZT patches were used, one as the sensor, one as the exciter providing the forced vibrations and the third acting as the actuator that provides an equal but opposite phase vibration/force signal to that of sensed so as to damp out the vibrations. The designed algorithm is implemented on Lab VIEW 2010 on Windows 7 Platform. © 2013, DESIDOC.
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    Parametric modeling and FPGA based real time active vibration control of a piezoelectric laminate cantilever beam at resonance
    (SAGE Publications Inc., 2015) Parameswaran, A.P.; Gangadharan, K.V.
    The operational efficiency and life of mechanical systems/structures depends to a large extent on their vibration control. Continuously occurring vibrations on the systems can cause fatigue and the effects of these vibrations are particularly severe if they occur at a frequency matching with that of the concerned systems natural frequency - a stage called resonance. This paper focuses on achieving active vibration control of a smart cantilever beam at its first resonant frequency as it is at this stage that maximum damage to the system performance is expected. The smart system is modelled in the parametric domain using finite element modeling techniques and the obtained model is validated through experimental means. The active vibration control is achieved by employing two control algorithms namely - output feedback and error based control through general purpose operating system (LabVIEW on Windows 7) as well as in real time operating system (LabVIEW FPGA coupled with compact reconfigurable input output modules) and the performances are compared thereby justifying the importance of the deterministic and reliable real time control over the usual PC based control in experimental studies. © The Author(s) 2014.
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    Engine gearbox fault diagnosis using empirical mode decomposition method and Naïve Bayes algorithm
    (Springer India sanjiv.goswami@springer.co.in, 2017) Vernekar, K.; Kumar, H.; Gangadharan, K.V.
    This paper presents engine gearbox fault diagnosis based on empirical mode decomposition (EMD) and Naïve Bayes algorithm. In this study, vibration signals from a gear box are acquired with healthy and different simulated faulty conditions of gear and bearing. The vibration signals are decomposed into a finite number of intrinsic mode functions using the EMD method. Decision tree technique (J48 algorithm) is used for important feature selection out of extracted features. Naïve Bayes algorithm is applied as a fault classifier to know the status of an engine. The experimental result (classification accuracy 98.88%) demonstrates that the proposed approach is an effective method for engine fault diagnosis. © 2017, Indian Academy of Sciences.
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    Analytical Studies on Ride Quality and Ride Comfort in Chennai Mass Rapid Transit System (MRTS) Railroad Vehicle
    (Springer, 2018) Gangadharan, K.V.; Chandramohan, S.
    In this paper analytical ride index studies and ISO 2631 based ride comfort analysis of a suburban MRTS railroad vehicle is presented. Track power spectral densities (PSDs) were used as inputs to a finite element (FE) model of the vehicle and track and the acceleration responses were computed using random vibration theory. From these responses, ride quality and ride comfort have been computed at different locations of the vehicle at different speeds in the vertical and lateral directions. © 2017, The Institution of Engineers (India).
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    Study the dynamic behaviour of seven DOF of full car model with semi-active suspension system
    (Inderscience Publishers, 2021) Hemanth, H.; Shamanth, S.; Devaraj, D.; Kumar, H.; Gangadharan, K.V.
    This paper presents an investigation on the ride comfort and road-holding performance of a vehicle equipped with the semi-active suspension system. The full car semi-active suspension model with 7 degrees of freedom (7 DOF) system is adopted for the study and a fuzzy-logic control strategy is considered for minimising the effect of road disturbance on vehicle performance. The responses of a vehicle have been analysed under the Indian average random road profile (ISO8608) against the conventional passive suspension system. The performance of the semi-active suspension system is evaluated by heave, roll and pitch acceleration of the vehicle body around its centre of gravity. The performance of a vehicle with the semi-active suspension system has been compared with the response conventional passive suspension system. The result specifies that, the semi-active suspension system with a fuzzy-logic controller reduces around 43% of vibration amplitude at the resonance frequency of vehicle than the passive suspension system. © © 2021 Inderscience Enterprises Ltd.