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.

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VIT University

Influence maximization, a classic optimization problem in social networks, targets to find a set of influential users capable of producing maximum influence spread under a particular diffusion model. Community structure, an important topological property of social networks, also plays a significant role in various dynamical processes, including the spreading of information in networks. Realizing the impact of community structure in information spreading, some community-based influence maximization methods have been proposed recently, and these studies show that community-based influence maximization methods perform better than the traditional influence maximization. However, the impact of the method used to detect communities on influence spread in the influence maximization problem is unknown, the need to verify and find the most effective community detection method suitable for influence maximization is essential. This paper addresses this problem by computing the influence spread of k influential nodes selected by an influential node selection method from the k largest communities extracted by the various community detection algorithms on a network. Experiments have been conducted to evaluate the performance of community detection algorithms and their impact on influence maximization on both artificial and real-world networks by employing four heuristic influence maximization methods under IC diffusion model.

Department of Information Security

School of Computer Science and Engineering

Vellore Campus

2021 International Conference on Advances in Electrical, Computing, Communication and Sustainable Technologies (ICAECT)

Evaluating the Effectiveness of Community Detection Algorithms for Influence Maximization in Social Networks

Interfacial adhesion of composite materials plays an important role in their mechanical properties and performance. In the present investigation, analysis of the interfacial properties of self-reinforced polyamide composites by using microbond multiple fibre pull-out test is emphasised. Microbond specimens prepared through thermal processing are tested for their interfacial properties by multiple fibre bundle pull-out tests and compared with that of traditional single fibre pull-out test specimens. Multiple fibre pull-out addresses the volume fraction as well as eliminates the possibility of fibre breakage before matrix shear. Higher scatter in the data in the samples is addressed in the present studies. FTIR and Fractographic studies are carried out for deep understanding of the post pull-out interfacial adhesion. © 2019, © 2019 Informa UK Limited, trading as Taylor & Francis Group.

Department of Design and Automation

School of Mechanical Engineering

World University root node

Journal of Adhesion Science and Technology

A comparative investigation of interfacial adhesion behaviour of polyamide based self-reinforced polymer composites by single fibre and multiple fibre pull-out tests

This study is an attempt to fill the gap in the fractographic studies conducted in various quasi-static mechanical tests to recognize the failure mechanisms and their correlation with its properties of self-reinforced polymer composite materials (SRC). SRCs are the class of composite materials developed by combining the same family of materials as constituent matrix and reinforcement. Thermoplastic linear aliphatic olefins like polyethylene (PE) and polypropylene (PP) are the systems analysed here for the purpose of deep understanding of their microstructural properties and correlations with the structural properties. Tension, in-plane shear and flexural parameters are tested, evaluated and correlated with corresponding fractographic features revealed under scanning electron microscopy (SEM). Selecting three different systems for this analysis also assisted in comparative study of various failure mechanisms and variations in fractographic features of SRCs with different chemical structure under quasi-static loading conditions. Fractography revealed failure mechanisms like matrix cracking, categories of fibre failures under different types of loading, effect of interface in bonding as well as fracture, shear flow patterns of matrix, phenomena like brooming, effect of coating in interface and fracture under quasi-static loading and behaviour matrix and reinforcement under various quasi-static loading. © 2020, Springer Nature Singapore Pte Ltd.

Lecture Notes in Mechanical Engineering

A Fractographic Study of PE, PP Self-reinforced Composites in Quasi-static Loading Conditions

A Powertrain is one of the major sources of excitation of a vehicle vibration and noise in off highway vehicles. It typically has a significant contribution in whole vehicle NVH characteristics. The structure borne energy of the powertrain is transmitted to the chassis and rest of the vehicle through powertrain mounts. Hence, it is of prime importance to design an effective powertrain mounting system in such a way that it will reduce vehicle vibrations to improve vehicle NVH as well as ride comfort, resulting in an effective vibration isolation system and ensuring long service life. In this paper, a newly developed an analytical tool for effective design of isolation system is discussed. For this model, powertrain is considered as a six degree-of-freedom system. Analytical calculations are implemented to find optimum mount design parameters i.e. stiffness, orientation and position of isolators to meet desired NVH targets. To achieve a good isolation characteristic, there is a necessity of decoupling of rigid body modes using optimization of various decoupling methods, which further helps in reducing the forces transmitted by the powertrain through the mounts. To evaluate coupling between the rigid body modes, modal energy distribution calculated from an analytical tool is used. The results from the developed analytical model are validated using commercially available tools for design of isolation systems. © 2019 SAE International. All Rights Reserved.

VIT Unitversity

SAE Technical Paper Series

Effective Powertrain Isolation of Off-Highway Vehicles

Self reinforced polymer composites possess a comparable shear and tensile strength unlike the glass or carbon fibre reinforced composites. Important deciding factors of overall efficiency of composite materials are the interfacial adhesion properties between the fibre and the matrix. Structural properties and processability of composite materials are also dependent on adhesion between the fibre and the matrix. Polypropylene and polyethylene self-reinforced composites are the systems investigated here for the purpose of analyzing the interfacial properties of these systems. Multiple fibre pullout test is an alternate method for single fibre pullout test with added advantages of more reliable statistically averaged data with less standard deviation and minimized chances for fibre breakage during testing. This test can also be verified for various volume fractions unlike single fibre pullout test. Micro bonds of matrix materials are cured on a bundle of fibres and by using a micro vise as an additional fixture, the interfacial strength and other interfacial properties are evaluated through fibre pullout. Surface tension between the fibre and the matrix plays an important role in this test. Thus from the contact angle and the frictional properties of the interface, the interface properties are evaluated. Interface properties obtained from this meso-mechanical semi empirical method are also compared with the properties evaluated from micromechanical formulations. Spectroscopic studies revealed the bonding characteristics during the interface formation and after failure. Fractography reveals the cause and nature of failure and substantiate the analysis. © 2019, The Author(s).

Fulltext

Applied Adhesion Science

Microbond fibre bundle pullout technique to evaluate the interfacial adhesion of polyethylene and polypropylene self reinforced composites

The eco-friendly nature as well as processing advantage, light weight and low cost have enhanced the attraction and interest of natural fibre reinforced composite. The objective of current study is to study mechanical and interfacial properties of jute reinforced low density polyethylene composites and sisal fibre low density polyethylene composites and to compare the properties with jute-sisal reinforced hybrid composite. The composites are to be prepared by film stacking followed by hot compaction process. Tensile, flexural, impact and hardness tests are to be conducted for mechanical characterization. © 2006-2018 Asian Research Publishing Network (ARPN).

Department of Thermal and Energy Engineering

Department of Automotive Engineering

ARPN Journal of Engineering and Applied Sciences

Fabrication and mechanical analysis of jute-sisal hybrid composite

The Production of thin wall austempered ductile iron components can have strength-to-density ratios that approach those of cast aluminum, making it theoretically possible to apply austempered ductile iron in high strength light weight parts. Short term austempering treatment process was used to obtain thin wall austempered ductile iron castings. The samples of 2 and 3 mm thickness were austenitized at 900°C for 30 minutes followed by holding at 350°C, 400°C and 450°C inoculated by Ce-Ca-Al-S-O-FeSi at 0.4% for 2, 5 and 10 minutes for each temperature. The austempered samples are comparatively harder than the as-cast ductile iron plates. The hardness also decreases with increase in austempering temperature for a given austempering time for thinner plates and for a thicker plates the hardness is more for the samples treated at 400°C than those treated at 350°C and 450°C for a given austempering time. The Yield strength and the ultimate tensile strength decreased for as-cast ductile iron and increased for thin wall austempered ductile iron samples with increase in plate thickness inoculated by Ce-Ca-Al-S-O-FeSi compare to Zr-Mn-Ca-Al-Ba-FeSi and Sr-Al-Ca-FeSi at 0.4%. © 2017 Elsevier Ltd.

Computer Science

Chennai Campus

Materials Today: Proceedings

Study on The Effect Of Austempering Temperature On The Structure-Properties Of Thin Wall Austempered Ductile Iron

Pipes are used all over the world for the basic utility of transfer of small solids, gases, slurries and liquids. Sometimes the term pipes and tubes is interchangeably used, the difference remains. The cross-sectional variations of these flow components results in the variation of characteristics under pressurized conditions. In the manufacturing of bend pipes the control over the outer diameter is quiet easily possible, but the inner diameter variations can be expected. At the bend, the thinning of the exterior part of the bend and the thickening of the interior part is seen. In the subsequent study the comparative flow analysis of the bend pipe of a circular cross-section and the oval pipe is analyzed. The characteristics flow velocity change, turbulence induced, density and pressure variations, temperature change in its course are focused. ANSYS FLUENT is used for the analysis of a standalone pipe of specified dimensions. © 2017 Published under licence by IOP Publishing Ltd.

IOP Conference Series: Materials Science and Engineering

Comparative study of bend pipe for circular section and ovality induced bend pipes

A Scramjet engine (Supersonic Combusting Ramjet) entails combustion at supersonic flow by generating high pressure through recompression (oblique) shock train. Shock Boundary Layer Interaction (SBLI) is an undesirable phenomenon that occurs inside the scramjet intake which has a detrimental effect on its performance. Due to adverse pressure gradient created by SBLI, the flow might be decelerated to subsonic speeds via normal shock. This leads to unstarting of the engine including other undesirable phenomena such as high drag and increased localized heating. The effect of cowl angle is studied on the performance of the scramjet engine in this study. A scramjet inlet prototype is designed in Solid Works followed by CFD analysis using ANSYS tool. The effects of cowl angle, static pressure rise, total pressure recovery and Flow Distortion are brought out. © IAEME Publication.

International Journal of Mechanical Engineering and Technology

Effect of cowl angle in the performance of scramjet air intakes

CFD analysis of straight and flared vortex tube

Self reinforced polymer composite systems mean that both the reinforcement and the matrix are of the same material but processed through different methods. Their shear and tensile strengths are comparable unlike the glass or carbon fiber reinforced polymer systems where the shear strength is only a fraction of the tensile strength. The system to be investigated are the polypropylene and polyethylene composites. Thermal and mechanical characterization of these systems were carried out which leads to interesting applications in transport, air, sea and land cargo containers, ultra light structures, packaging and electronic packaging.

International Journal of ChemTech Research

Processing and mechanical characterization of self reinforced polymer composite systems

The main objective of this paper is to fabricate and test the Jute-Epoxy braided as well as short fibre reinforced composite which is of low cost, low density, high specific strength, no health risks, renewable, environment friendly and lower energy requirement for processing. The jute fibres used have undergone alkali treatment to improve their properties and blended with epoxy resin and cured. The later stage of our work deals with the Tensile Test of both types of specimens, Impact & Flexural test of Braided composite according to the ASTM standards for Plastics. Further an extensive comparison of braided & short fibre composite has been done along with finite element analysis to validate the results.

Fabrication, testing and analysis of braided and short fibre reinforced jute epoxy bio-composite

Today with the depleting natural resources and excessive accumulation of non-degradable plastic material in our day to day life has given rise to the use of bio degradable material.The main objective of this paper is to fabricate and test the jute bio-composite which is of low cost, low density, high specific strength, light weight, no health risks, renewable, environment friendly and lower energy requirement for processing. The jute composite used has undergone alkali treatment and blended with epoxy resin and cured. The later stage of our project deals with the Tensile Test, Impact Test and Flexural Test of the specimen according to the ASTM standards for Plastics. © Research India Publications.