Mechanical

Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

&nbsp;

&nbsp;

VIT University

School of Mechanical Engineering

Direct metal laser sintering (DMLS) is one of the methods in layer manufacturing technologies by which metal powder can be directly used to produce both prototype and production tools. The components manufactured by DMLS should have essential hardness for its application in the industry. This study was carried out to determine the optimum process parameters influencing the hardness of the components produced by DMLS. Sintering speed, hatch spacing, post contouring, infiltration and hatch type are the process parameters taken up for study. Statistical design of experiments using Taguchi’s orthogonal array was employed for this study. The experimental data obtained were analyzed using ANOVA. From the results, it is found that one of the process parameters; scan spacing affects the hardness of the parts produced by this technology to a significant extent.

Department of Design and Automation

Vellore Campus

Chennai Campus

VIT Unitversity

Advanced Materials Research

Investigation on the Effect of Process Parameters on Hardness of Components Produced by Direct Metal Laser Sintering (DMLS)

Application of fused deposition modelling components are gaining popularity in functional application. In order to use these components directly for functional application, reliability in service has to be acheived. A Reliability analysis was caried out on components manufactured by fused deposition modelling. A standard test specimen as per ASTM was prepared and tested for fatigue cycles to failure. Bending stress was calculated prior to the fatigue testing by varying the slice thickness. Fatigue test was carried out with differnt loading condition. Fatigue test results were subjected to weibull analysis to determine the reliability of FDM components. The Weibull design values were calculated and Weibull distribution plot for failure was plotted and analyzed. Estimation of reliabilty for different cycles to failure was also found out.

Applied Mechanics and Materials

Reliability of Fused Deposition Modelling (FDM) Components on Fatigue Cycles to Failure Using Weibull Analysis

An analytical study is presented for the vibration characteristics of thin circular plates with rotational elastic edge support and resting on an elastic foundation. The Winkler model was used to describe this foundation. The exact analytical method is used to derive the frequency equation of the plate with elastic support and resting on this foundation. Parametric investigations of the vibration of circular plates with an restrained elastically edge against rotation and resting on an elastic foundation have been carried out with respect to various rotational stiffness parameters, foundation stiffness parameters, and boundary conditions. Twelve vibration modes are presented. The location of the stepped region with respect to rotational restraint changed very little and moved from the range of 0:014 26† [10:006 204 8†]-1 134:227 [10:025 94] to 0:017 58 [14:001 133]-6 352:958 2 [14:658 356]. Here, † represents the rotational spring stiffness ratio, and † represents the foundation stiffness ratio. Extensive data are tabulated so that pertinent conclusions can be arrived at on the influence of rotational edge restraint and the foundation parameters of a Winkler foundation on the natural frequencies of uniform thin isotropic circular plates.

World University root node

The International Journal of Acoustics and Vibration

Free Vibration of Circular Plates with Elastic Edge Support and Resting on an Elastic Foundation

Wavelength Division Multiplexing (WDM) is a boon of Light wave Technology as it increases the transmission capacity and enhances the transmission distance by using optical amplification. The capacity of the present system is limited by the noise generated by the amplifiers and interactions due to nonlinearities like Cross Phase Modulation (XPM), Self Phase Modulation(SPM), Four Wave Mixing(FWM) and Stimulated Raman Scattering(SRS). This paper focuses on the design of WDM Network in order to analyze the effect of XPM on the optical transmission rate. Also the papers focus on the suppression methods that can be used in order to remove the degrading effects of these non linearity's. © 2012 Springer-Verlag.

Department of Instrumentation

School of Electrical Engineering

Communications in Computer and Information Science Global Trends in Computing and Communication Systems

Design of WDM Optical Networks for the Analysis of Cross Phase Modulation and Self Phase Modulation

Anodization is an easily viable technique useful for producing TiO 2 coatings on titanium substrates. Nano-crystalline anodic TiO 2 structure was produced on titanium at 20 V using 1 M Na 2SO 4 and 0.5% NaF and consolidated by a further heat-treatment. Micro-crystalline anodic TiO 2 was produced on titanium by applying a galvanostatic current density of 70 A/m 2 in water medium. To assess the usefulness of these nano- and micro-oxides for bone implant stability, physical properties and bone in vitro bioactivity including HA formation, cellular affinity and mouse-tissue morphogenesis, were evaluated. Bioactivity of the different anodic surfaces was evaluated by treating them in a simulated body fluid (SBF) to form hydroxyapatite (HA) and the rates of HA formation were compared. Deposits of HA could be seen on the nano-oxide surface within 7 days, whereas HA was detected only after 14 days on the micro-oxide surface. In vitro cell culture tests done using mouse osteoblasts indicated that the nano-oxides showed statistically significant cell activity than the micro-oxides and the machined titanium. Branching morphogenesis test done for 72 h on these surfaces showed more branching on the micro- and nano-oxides as compared with titanium surface. © 2012 Elsevier B.V.

Materials Science and Engineering C

In vitro bioactivity evaluation of nano- and micro-crystalline anodic TiO 2: HA formation, cellular affinity and organ culture

This article presents the findings of the empirical study of proposed framework of manufacturing excellence (ME) in the Indian industry. The study includes companies from five major sectors, namely automobile, process, machines and equipment, electronics and components and textile. Responses from 90 companies were analysed to explore the validity and reliability of the proposed framework of ME in Indian industry. The developed questionnaire is outlined along with the results obtained from the analysis of the data from the Indian industry. The framework shows high level of reliability and validity. © 2012 Taylor & Francis.

Production Planning and Control

Validity and reliability of proposed framework of manufacturing excellence in the Indian industry

Since the development of the original value stream mapping (VSM) by Taichi Ohno at Toyota, a number of authors have suggested several additional VSM tools to understand and improve the value stream through waste reduction. A single best VSM tool, though effective in dealing with a certain waste type, becomes redundant as other wastes take centre stage and/or organisational priorities change. To overcome this, a decision framework based on a novel formulation of the integrated analytical hierarchy process (AHP) - pre-emptive goal programming (PGP) has been proposed. This framework not only guarantees accurate selection of an ideal VSM tool, based on the current organisation's priorities, but also aids the decision maker to arrive at the optimum implementation sequence of a chosen set of VSM tools to identify and reduce all wastes present in the system, thereby maximising organisational performance in the shortest timeframe. © 2012 Copyright Taylor and Francis Group, LLC.

International Journal of Production Research

A decision framework for maximising lean manufacturing performance

In most of the industries related to mechanical engineering, the usage of pumps is high. Hence, the system which takes care of the continuous running of the pump becomes essential. In this paper, a vibration based condition monitoring system is presented for monoblock centrifugal pumps as it plays relatively critical role in most of the industries. This approach has mainly three steps namely feature extraction, classification and comparison of classification. In spite of availability of different efficient algorithms for fault detection, the wavelet analysis for feature extraction and Naïve Bayes algorithm and Bayes net algorithm for classification is taken and compared. This paper presents the use of Naïve Bayes algorithm and Bayes net algorithm for fault diagnosis through discrete wavelet features extracted from vibration signals of good and faulty conditions of the components of centrifugal pump. The classification accuracies of different discrete wavelet families were calculated and compared to find the best wavelet for the fault diagnosis of the centrifugal pump. © 2012 Elsevier B.V.

Applied Soft Computing Journal

A comparative study of Naïve Bayes classifier and Bayes net classifier for fault diagnosis of monoblock centrifugal pump using wavelet analysis

In this paper, transverse vibrations of thin circular plates with guided edge and resting on Winkler foundation have been studied on the basis of Classical Plate Theory. Parametric investigations on the vibration of circular plates resting on elastic foundation have been carried out with respect to various foundation stiffness parameters. Twelve vibration modes are presented. The location of the stepped region with respect to foundation stiffness parameter is presented. © 2012 IAU, Arak Branch. All rights reserved.

Journal of Solid Mechanics

Vibrations of circular plates with guided edge and resting on elastic foundation

This study is aimed at carrying out a finite element analysis on a roll cage of a vehicle used for student competitions around the world. The design process was carried out using a CAD package and analysis was done using finite element analysis software, ANSYS. Impact test was carried out on the roll cage under different conditions and the effect on the structural members are studied and discussed. The results are very much helpful and assure that the car is in safe condition in case of a crash or accident. Finite Element Analysis (FEA) is also carried out with the frame against torsional loading. Two different materials were considered for the analysis. The results of displacement of frame, nodal solution, element solution and bending moment are discussed.