2. Conference Papers
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Item Ball bearing fault diagnosis based on vibration signals of two stroke ic engine using continuous wavelet transform(2020) Ravikumar K.N.; Madhusudana C.K.; Kumar H.; Gangadharan, K.V.Ball bearings are used in the different critical fields of engineering applications such as IC engine, centrifugal pump and fans. In IC engine, the ball bearing is one of the critical components and it takes various types of dynamic loads and stresses. Condition monitoring of such ball bearing is very significant to avoid the catastrophic failure of rotating components in IC Engine. This article describes the fault detection of roller ball bearing of an IC engine gearbox with the use of signal processing technique such as spectrum analysis and Continuous Wavelet Transform (CWT) analysis. Vibration signals of IC engine are used to identify the fault in the ball bearing and to detect the healthy and fault bearing conditions. © Springer Nature Singapore Pte Ltd 2020.Item Application of vibration analysis and data mining techniques for bearing fault diagnosis in two stroke IC engine gearbox(2020) Ravikumar K.N.; Kumar H.; Gangadharan, K.V.This paper is about monitoring of ball bearing used in the IC engine gearbox using condition monitoring techniques. Experiments are conducted on two stroke IC engine which is driven by the 3HP DC motor. Vibration signals are acquired from the gearbox with triaxial accelerometer. Ball bearing with good and induced faulty (outer race fault, inner race fault, ball fault, inner and outer race fault) conditions were used in the analysis. Fault diagnosis of the ball bearing has been carried out using data mining (DM) techniques. In DM there are three stages viz.; feature extraction, feature selection and feature classification. For all the conditions of bearing, statistical and empirical mode decomposition (EMD) features are extracted from the vibration signals. Decision tree technique (J48 algorithm) is used in the analysis for selecting significant features from the feature vector. From the chosen features, ball-bearing conditions are classified using random forest algorithm. Results obtained from the different classifiers were compared, and a better classification algorithm with a decision tree will be suggested for condition monitoring of the rotating components. © 2020 Author(s).Item The effect of inclination angle of shock absorber on ride comfort and road holding of two-wheeled vehicle(2020) Hegale A.; Puneet N.P.; Kumar H.; Gangadharan, K.V.The main purpose of shock absorber assembled in a vehicle is for ride comfort of passengers and better control of moving vehicle by driver. The shock absorber is assembled in between vehicle body known as sprung mass and a combine mass of wheel and suspension known as unsprung mass. In the present work, the effect of inclination angle of shock absorber on ride comfort and road holding of two-wheeled vehicle has been analyzed. For this study, a commercial viscous damper of a two-wheeled vehicle is characterized for different frequency and sinusoidal stroke to find the damper characteristics. A linear curve is fitted for the maximum velocity versus damping force for rebound and compression region. The fitted curve and a bump road profile used to analyze the ride comfort and road holding of the two-wheeled vehicle for three different inclination angles made by shock absorber. The stiffness of suspension increases due to the inclination which influences the ride comfort and road holding. © 2020 Author(s).Item Rheological characterization of tragacanth gum coated carbonyl particles based magnetorheological fluid(2020) Swaroop K.V.; Aruna M.N.; Kumar H.; Rahman M.R.The surface modification of soft carbonyl particle (CIPs) based magnetorheological (MR) fluids is the most popular method to solve sedimentation problem. In this present work,the two MR fluidswere prepared using pure CIPs (MRF#1) and Tragacanth gum coated CIPs (Tg/ CIPs) (MRF#2) are dispersed in hydraulic oil as a carrier fluid. The morphology, elemental composition and magnetic saturation properties were investigated using scanning electron microscopy (SEM),energy dispersive spectroscopy (EDS), superconducting quantum interface device (SQUID) analysis respectively. In addition to that,chemical bonding and thermal oxidation resistance of CIPs and (Tg/ CIPs) was analyzed using Fourier-transform infrared spectroscopy FTIR and thermo-gravimetric analyzer (TGA). The rheological properties of CIPs and Tg/CIPs based MRFs was tested to determine the flow behaviourat different currents 0,1,2,3 and 4Amps. The experimental results found that Tg/CIPs based MRFs is having higher yield stress of about (16kPa) than pure CIPs (15kPa). The decrease in the density of Tg/CIPs showed better sedimentation ratio (i.e r=91%) than the pure CIPs based MRFs which was observed using naked eye visual method. © 2020 Author(s).Item Optimal Parameters Identification of Quarter Car Simulink Model for Better Ride Comfort and Road Holding(2021) Puneet N.P.; Hegale A.; Kumar H.; Gangadharan, K.V.Advancement in vehicle technology has explored many possibilities for improvement, keeping customer satisfaction in mind. One major criterion which a passenger always wishes to possess is ride comfort. But the suspension parameters suitable for a good ride comfort may not support another salient feature called road holding. Hence, in this work an attempt has been made to simultaneously improve the ride comfort and road holding, using a quarter car test model using MATLAB Simulink for a commercial light motor vehicle. Initially, a commercially available passive damper of light motor vehicle has been characterized using dynamic testing machine (DTM) in order to obtain its force–displacement behavior and damping nature. A design of experiment (DOE) has been conducted by taking vehicle velocity, sprung mass, spring stiffness and damping coefficient into consideration, for experimentation using quarter car model. Regression equations have been extracted for relating the problem parameters to both ride comfort and road holding. Analysis of variance (ANOVA) has been used to know the influence of each parameter toward the target response. In the later stage, response surface methodology optimization technique has been used in order to optimize the parameters for better ride comfort and road holding. Optimized parameters are substituted again in the quarter car model, to validate the results obtained during optimization. The present work concluded with an optimal ride comfort and road holding and proved the effectiveness of optimization technique in achieving so. © 2021, The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.Item Optimal Design of Rotary Magneto-Rheological Drum Brake for Transfemoral Prosthesis(2021) Saini R.S.T.; Kumar H.; Chandramohan S.; Srinivasan S.Semi-active technology offers good advantages in terms of controllability and adaptability. Magneto-rheological (MR) fluid is a class of smart fluids which display significant changes in its rheological properties under the influence of a magnetic field. Previous studies carried out using MR brake for the transfemoral prosthetic device were of multi-plate models which are complex in design and also to manufacture. Therefore, in the present study, a multi-coil rotary inverted drum brake is optimized with braking torque as the objective function. One of the advantages of the multi-coil design from multi-plate is that the former has fewer components and leads to a simpler design. The outermost geometric constraints are decided based on the knee cross-sections in anterior-posterior and mediolateral directions. Four design geometric variables are selected which are: coil depth, coil height, casing axial thickness, and casing radial thickness. A design of experiments technique is used to obtain 27 combinations of design variables. Magnetostatic analysis at each design point is performed and average flux densities in the annular and the radial gaps are determined. Regression analysis is conducted on the design data to obtain braking torque as a function of four design variables. Later, genetic algorithm is used to obtain the optimum geometric dimensions. A total maximum braking torque of 13.4 Nm is obtained using the optimum dimensions for a design current of 2 A. © 2021, The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.Item Investigation of steady state rheological properties and sedimentation of coated and pure carbonyl iron particles based magneto-rheological fluids(2020) Swaroop K.V.; Aruna M.N.; Kumar H.; Rahman M.R.MR fluids face a major problem of sedimentation rate due to the high- density difference between the magnetic particles and the carrier medium that affects the performance of the magnetorheological devices. In this work, two MRF samples are prepared, where MRF-1 and MRF-2 are pure and coated carbonyl iron particles (CIPs) based MR fluids. The surface modification of the CIPs is performed using the solvent dispersion method to improve the sedimentation rate. The spherical shape and particle size analysis of the pure CIPs and coated CIPs' morphology is investigated using the Scanning Electron Microscope (SEM). The Thermal Gravimetric Analysis (TGA) shows that the coated CIPs have high thermal stability and confirm that 6% by wt. coating is present in the coated sample. The chemical bonding of the coated CIPs is detected using the Fourier Transform Infrared Spectroscopy (FT-IR). The saturation magnetization (Ms) of pure and coated CIPs is 245 emu/g and 120 emu/g, respectively, at 15 kOe, which is obtained by using a superconducting quantum interface device (SQUID). The rheology flow curve properties show that MRF-1 and MRF-2 exhibit yield stress of about 10 kpa and 9 kpa, respectively, for varying magnetic fields ranging from 0 to 343 kA/m. The Herschel-Bulkley model is fitted with the experimental data and the shear thinning behaviour is observed for both MR fluids. The sedimentation study shows that MRF-2 has better settling rate than MRF-1, which is observed by using the visual observation method up to 600 h. © 2020 Elsevier Ltd. All rights reserved.Item Experimental investigation of frequency and damping characteristics of magneto-rheological fluid core sandwich beams(2020) Nagiredla S.; Joladarashi S.; Kumar H.In dynamic systems mechanical vibration amplitudes may range from a few nanometres to meters. When the vibration amplitudes are high the system may lead to failure or lost it function. Structures often tend to failure because of the high vibration amplitudes. These vibrations can be reduced by changing the stiffness or damping of the structure. One of the approaches is semi-active damping achieved by using Magneto-rheological fluid (MRF) as core material in a sandwiched beam. Magneto-rheological(MR) fluids change from fluid state to quasi-solid state when it is activated by a magnetic field. Adding MR fluids to mechanical systems may significantly improve their dynamic response. This study aims to analyse the free vibration response of the cantilever sandwich beam filled with the MR fluid as core material with Magnetic field intensity. A sandwich cantilever beam with Composite material as face layer and Magneto-rheological fluid as core was fabricated. Free Vibration test is performed on a sandwich beam filled with MR fluid under the external magnetic field generated by permanent magnets. Magnitude of Viscoelastic moduli of the MR fluid increases with magnetic field intensity as the fluid becomes semi-solid. The aim of the work is to analyse the influence of Magneto-rheological effect on the beam response with respect to externally applied magnetic field. Vibrations of the beam are registered with magnetic field and without magnetic field strength. Obtained data is utilized to analyse the dependency of magnetic field strength on the beams natural frequency and damping. © 2020 Author(s).Item Experimental investigation and mathematical modeling of automotive passive damper for SUV suspension system(2020) Desai R.M.; Jamadar M.-E.-H.; Kumar H.; Joladarashi S.Dampers are energy dissipating devices used along with energy absorbing devices like coil springs to form the major parts of an automobile suspension system. They provide the passengers of the vehicle the desired comfort and the vehicle the necessary stability and road holding. In the present work, a viscous damper of twin tube design working in the passive mode is evaluated on a damper testing machine and its performance is characterized. Its behavior at different velocities and frequencies of excitation is studied. Using the dissipated energy method, the equivalent damping coefficient of the damper is calculated for different frequencies of excitation. Mathematical models are developed for the force vs velocity behavior of the damper as the damper force is a function of the damper piston velocity. These mathematical models based on the experimental results will be very much useful in designing an alternative or improved suspension system for the vehicle under consideration. © 2020 Author(s).Item Effect of magnetic permeability, shearing length, and shear gap on magnetic flux density of the magnetorheological damper through finite element analysis(2020) Kumar Kariganaur A.; Kumar H.; Arun M.The performance of the magnetorheological (MR) damper is determined based on the damping force of the damper which is used to reduce the unwanted vibrations in the automobile suspension system. In this study, an axisymmetric magnetorheological damper model is analyzed using ANSYS finite element (FE) analysis to simulate a distribution of magnetic field in the fluid flow region. Firstly, the materials used for the fabrication of MR damper such as SA1018 and Aluminium are used for the permeability analysis for applied current in shear mode operation. It is evident from the result that, a material with higher magnetic permeability (SA1018) gives higher magnetic flux density in the fluid flow gap. By using SA1018 material for further study the effect of increase in shear gap and shearing length of the MR damper, there is a exponential decay in the magnetic flux density in the flow gap. And finally, by using the response surface methodology optimum values are obtained for maximum magnetic flux density. © 2020 Elsevier Ltd. All rights reserved.