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.

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VIT University

School of Mechanical Engineering

An attempt has been made to improve the interfacial strength of AlSiC composites which are widely used in defense and automotive sectors. Enhancement of interfacial strength is studied by radial crushing of composites reinforced with electroless nickel coated SiC particled and manufactured by powder metallurgy process. It was visualized that ultimate breaking load for electroless Nickel coated SiC reinforcement has increased by 40 % with respect to uncoated reinforcement. XRD data confirmed the existence of Nickel in Aluminium matrix. SEM studies revealed the incorporation of Nickel with Aluminium and Silicon carbide. Because of improved interfacial strength and microhardness values the so obtained composites can be used for heavy machineries as an alternate to monolithic alloys.

Department of Chemistry

School of Advanced Sciences

Vellore Campus

Department of Manufacturing Engineering

Chennai Campus

Journal of Materials and Environmental Science

The influence of electroless nickel coated SiC on the interface strength and microhardness of aluminium composites

The ongoing research in the field of cellular manufacturing systems (CMS) is progressing on diverse fronts such as dynamic CMS, virtual CMS, etc. However, the following fundamental issues - 'how an operations manager in an organisation would make a decision of choosing/selecting CMS, when he/she is confronted with different alternatives?', 'how would the manager make a decision, if the decision factors/criteria/attributes (for the sake of simplicity, it will be called as 'elements') are inter-related?' are not given adequate importance. To address the above-mentioned issues, a hypothetical case study is utilised to demonstrate how the managers' can make such a strategic decision using the analytic network process (ANP), one of the recently developed multi-criteria decision-making (MCDM) models that has the capability to model the relationships that exist within and between different categories comprising of various decision elements. The results obtained revealed that CMS is a better alternative under the given case situation. Copyright © 2014 Inderscience Enterprises Ltd.

World University root node

International Journal of Services and Operations Management

An application of analytic network process for the selection of cellular manufacturing systems

Fulltext

Procedia Materials Science

Fault Diagnosis of Single Point Cutting Tool through Vibration Signal Using Decision Tree Algorithm

Monoblock centrifugal pumps are employed in variety of critical engineering applications. Continuous monitoring of such machine component becomes essential in order to reduce the unnecessary break downs. At the outset, vibration based approaches are widely used to carry out the condition monitoring tasks. Particularly fuzzy logic, support vector machine (SVM) and artificial neural networks were employed for continuous monitoring and fault diagnosis. In the present study, the application of SVM algorithm in the field of fault diagnosis and condition monitoring is discussed. The continuous wavelet transforms were calculated for different families and at different levels. The computed transformation coefficients form the feature set for the classification of good and faulty conditions of the components of centrifugal pump. The classification accuracies of different continuous wavelet families at different levels were calculated and compared to find the best wavelet for the fault diagnosis of the monoblock centrifugal pump. © 2014 Karabuk University

Engineering Science and Technology, an International Journal

Fault diagnosis of monoblock centrifugal pump using SVM

Aim: Peripheral vasculature of the human body includes the blood vessels that supply the extremities and the major vessels that supply the brain. Major peripheral vascular pathologies that affect the peripheral vasculature are arterial occlusive disease or stenosis (vessel narrowing), aneurysms (vessel enlargement) and various types of trauma. The aim of this study was to develop a peripheral vascular endovascular stent-graft for the treatment of various pathologies that affect peripheral vasculature, in particular, femeropopliteal arterial disease. The stent graft is composed of a nitinol framework covered by a polymeric tube. Methods: The present work explores an innovative device design which includes separate nitinol rings encased between layers of ePTFE. The vessel remodeling is studied by considering various vessel diameters and the efficacy of the device is studied by varying the nitinol wire diameter (0.1 to 0.25mm), the number of struts in the ring (6 to 10) and the height of the struts (1 and 2mm). Finite element studies were done to understand the best design for the changing vessel morphology by studying the crimping pattern and the radial stiffness of a single ring. A single ring is modeled as an axisymmetry FE-3Dmodel. An 8-node hexahedral element SOLID185 was used for this study. The nodes of the symmetric model were constrained and the radial displacement was given to the model. The boundary conditions were the same for crimping and deployment. Results: The results of the FEA analyses show 1 mm height ring with 0.15mm thickness and 8 struts combination provides the ideal crimped profile of 1.7mm and radial force of 0.996N/mm when deployed in a 6mm vessel diameter. Conclusion: The finite element analysis results show that the radial force and crimping analysis perform a vital role in determining the device design and geometry. © Springer International Publishing Switzerland 2014.

Department of Thermal and Energy Engineering

IFMBE Proceedings The 15th International Conference on Biomedical Engineering

A Study of Mechanical Behavior of an Encapsulated Stent Design Using Finite Element Analysis

Stay cables of the cable-stayed bridge exhibits a large amplitude vibration under the action of wind and rain and which may have a greater effect on the fatigue life of the stays. These large amplitude vibrations were strongly influenced by variety of factors concerning the positioning of the cable (inclination angle), meteorological parameters (rain, wind speed and wind direction) and the structural parameters like damping and frequency. This paper explains the effects of wind speed, rainfall, damping, cable diameter, cable inclination angles, wind yaw angles on the vibration amplitude of the stay cables with diameters 0.155 m and 0.128 m. The observations show's large amplitude vibrations when the cable is inclined at 25° and 30° and wind yaw angles are from 30° and 35° under 10 mm/hr rainfall condition.

Journal of Structural Engineering (India)

Effect of wind speed, wind direction, rainfall intensity, damping and cable diameter on vibration amplitude of the cable

Influence of ageing temperatures and ageing time intervals on the intermetallic phases of high Mo superaustenitic stainless steel (SASS) is studied. To form the intermetallic phases the alloy was aged for 1 hour and 10 hours at different temperatures in the range of 500-1000°C. Chi forms at temperatures up to 800°C. Sigma forms above 900 or 1000°C depending upon the ageing time. A property diagram is simulated using Thermo-calc software to corroborate the formation of chi and sigma phases as a function of ageing temperatures. EDS of sigma indicated its higher Mo content compared to the chi phase. Chi is enriched in chromium while sigma is enriched in Mo. © (2014) Trans Tech Publications, Switzerland.

Applied Mechanics and Materials

Quantitative analysis of intermetallic precipitates in high mo superaustenitic stainless steel

The buoyancy driven flow characteristics through horizontal passage between two enclosures are numerically investigated. The two-dimensional physical model consists of upper and lower enclosures filled with cold and hot fluids connected through ceiling vent. Non-Boussinesq variable density approach is used to model the density variations by primitive variable method. The governing equations are solved by Simplified Marker and Cell (SMAC) algorithm on non-staggered grid using high accuracy compact finite difference schemes. The Grashof number is varied from Gr = 10 6 to 5 × 10 7 The nonlinear exchange of lighter and heavier fluids through vent are investigated by varying vent aspect ratio. The net mass flow rate through horizontal passage are oscillatory and bidirectional. The critical Grashof number is identified, and beyond this instabilities intensifies leading to complex flow behavior inside enclosures. The vent widths D =0.05H and 0.2H reduces flow perturbations and enhances stable flow behavior across the vent. Chaotic flow originates for critical vent widths 0.1H ≤D ≤0.15H , and nonlinear oscillations evolves till the system reaches quasi-steady state. Reduced vent thickness results in higher oscillation frequencies and better mixing rates between enclosures. The present mathematical model and numerical method showed good agreement with the existing results available in literature. © 2014 Elsevier Ltd.

Computers and Fluids

Numerical investigation of instability patterns and nonlinear buoyant exchange flow between enclosures by variable density approach

The problems of communication disorders are many. The individual who suffers from such a disorder, such as stuttering, faces difficulty in getting his or her point across. Communication is a holistic process which spans multiple levels. An error in any one level can lead to misunderstanding and may even result in severe repercussions. People who stutter have a disadvantage. The time lag between what a person without this condition says and what a person with this condition says is appreciable, as stuttering causes many words, vowels and fillers to be repeated. This paper suggests a method for improving communicability of stutter signals obtained from audio recording. Under the method suggested, audio signals are read and spliced into different portions depending on the length of the given signal. Presence of stutter type repetitions are assessed by applying loops. Repeated signals, if present, are eliminated using windowing techniques. In totality this results in the smoothening out of the signal and removing disfluency-inducing repetitions. © Springer International Publishing Switzerland 2014.

Department of Control and Automation

School of Electrical Engineering

ICT and Critical Infrastructure: Proceedings of the 48th Annual Convention of Computer Society of India- Vol II Advances in Intelligent Systems and Computing

Analysis of Stutter Signals with Subsequent Filtering and Smoothening

The present work shows the effect of weld penetration levels on the stress level and the fatigue life at the weld joints. Finite element analysis was used to estimate stress pattern of welded joints having different levels of penetration for "Bend Loading" and "Tensile loading" were selected for studies. Specimens with variation in the penetrated throat length between 1.80mm to 0.60 mm were selected. Study has clearly highlighted the corresponding fluctuations observed in the fatigue life with change in weld penetrations. A side loading will be more detrimental than a tensile loading. © 2014 Published by Elsevier Ltd.