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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The objective of this study is to investigate the moment-rotation behaviour of the extended end plate long bolted moment connection using numerical, experimental and component method approaches. Totally thirty six models of the cold formed steel beam-column (hollow and concrete filled column) connection with different arrangement of long bolts are modeled and analysed using the finite element software ANSYS APDL. The cross-sectional dimension of the column and beam section is 50 mm × 100 mm × 2 mm. The length of column and beam section is 900 mm and 700 mm, respectively. The end plate size is 100 mm × 150 mm × 2.5 mm/4.0 mm and 6 mm diameter long bolts are used to connect the members in the joint. It is observed that the increase in the number of bolts increases the initial rotational stiffness and design moment capacity of the connections significantly. Substantial enhancement in the initial rotational stiffness and design moment capacity of the connection is achieved by using concrete fill in the column. From the experimental validation, it is noticed that the finite element models satisfactorily predict the actual behaviour of the extended end plate bolted moment connections. Also the initial rotational stiffness of the connections is determined based on the component method as specified in Euro Code 3(BS EN 1993-1-1 2005, BS EN 1993-1-8 2005) and the results indicate that the predictions based on the proposed analytical model agree well with the simulation model. © 2021, Korean Society of Steel Construction.

Civil

School of Civil Engineering

Chennai Campus

World University root node

International Journal of Steel Structures

Extended End Plate Long Bolted Joint Using Cold Formed Steel Hollow and Concrete Filled Column

The use of castellated beams has increased a lot in the past few years in all types of structures. The castellated beam is one of the several methods used to decrease the weight and cost of steel used in the construction. In castellated beams, increased depths can be achieved without increasing the self-weight of the structure. The significant advantages of castellated beams are better possessing bending moment capacity, ease of providing service pipes and wires, and aesthetic appearances. The castellated beams are made by making a zigzag cut through the web according to the desired opening shape and size, and then the two parts are welded together. In this work, static and dynamic analyses of the castellated steel beam section (ISMB 300) are performed to compare deflection, stress distribution, shear Stress, amplitude, and natural frequency. The investigation is done using ANSYS 18. The Castellated beam having a maximum opening of size 0.6h is used for the study. The castellated beams have proved to be useful under a light-uniform load. © 2021 Institute of Physics Publishing. All rights reserved.

Department of Mathematics

School of Advanced Sciences

Vellore Campus

Fulltext

Journal of Physics: Conference Series

Static and dynamic analysis of steel beams with web openings

This paper presents the design and development of stretchable and deformable broadband antenna using low-cost silicone rubber-based dielectric substrate. A slot is introduced in the substrate to improve the stretchable behaviour. The dielectric properties of the substrate are measured using suspended ring resonator method. The proposed antenna uses silver elastomeric Lycra fabric as the conductive medium. The resistivity of the conducting Ag fabric is 1 Ω per sq. mm. The conducting patch and ground plane are attached with the substrate using silicone-based adhesive. The fabricated antenna is tested for its resonant characteristics using the vector network analyser. © 2020, Indian Academy of Sciences.

School of Electronics Engineering

Pramana - Journal of Physics

Dynamic frequency analysis of stress–strain-dependent reversibly deformable broadband RF antenna over unevenly made elastomeric substrate

Stretchable dielectrics exploit their inherent elasticity to enable new types of transducers that convert mechanical energy into electrical energy. Electric power can be altered by simply stretching or shrinking a low cost material, and hence is more desirable now-a-days. The challenge of a material to be sustainable for lifelong is a great task for varying environmental conditions. It could be overcome by making functional coatings over the substrate. The challenge includes choosing resins that stretch along with the substrate uniformly without affecting its dielectric properties. In this article, the effect of different polymer coatings over the dielectric elastomer Lycra is investigated. Elastomeric coatings with the polymer resins silicone, TPU and Epoxy were made by doctor blade method. Dielectric properties measurements and Tensile strength tests pointed out the effectiveness of the coated substrates in stretchable RF devices. SEM micrograph images show the sustainability of the resin coated fabric for varying environmental conditions. © 2020 National Institute of Optoelectronics. All rights reserved.

Journal of Optoelectronics and Advanced Materials

Polymer resin coating over dielectric elastomer for effective stretchable RF devices

We report the growth process and linear and nonlinear optical characterization of high quality improvised semiorganic 2A5NPDP single crystal using the modified SR method for the first time. The major difficulties for the growth of 2A5NPDP single crystal have been resolved with the aid of a temperature lowering method. After optimization of the growth conditions, a transparent 2A5NPDP single crystal was harvested with a size of 85 mm length and 10 mm diameter over a period of 60 days. The growth rate of the modified SR method grown crystal was found to be 10 times higher than that of the conventional slow evaporation solution technique (SEST) grown crystal. The unit cell parameters of the grown crystal were ascertained by the single crystal X-ray diffraction (SXRD) and powder X-ray diffraction (PXRD) techniques. The high crystalline perfection of the crystal was ascertained by using a high-resolution X-ray diffraction (HRXRD) technique. The presence of multifarious functional groups of the 2A5NPDP crystal were confirmed by Fourier transform infrared (FT-IR) and Fourier transform Raman (FT-Raman) spectral analyses. The thermal property was assessed by the thermogravimetric (TG) and differential thermal analysis (DTA). It shows that the grown crystal withstands temperature up to 175 °C. UV-vis-NIR analysis was used to measure the linear optical property while third-order nonlinear optical properties were ascertained using Z-scan and optical limiting (OL) techniques. The optical limiting threshold of conventional method grown crystal is 5.7 mW/cm2, whereas the modified SR method grown crystal is 4.7 mW/cm2. Low value of limiting threshold indicates that the grown crystal has minimum defects. Finally, 800 nm wavelength of 140 fs at 80 MHz repetition rate obtained from a Ti:sapphire oscillator was used for the terahertz (THz) generation between 0.1 and 2.1 THz range. The efficiency of the generated THz signal was measured using another 800 nm wavelength of 40 fs, at 1 kHz repetition rate obtained from a Ti:sapphire amplifier. The generated THz signal is separated out from unconverted 800 nm using Teflon filters, and power is measured using a pyrometer. The maximum conversion efficiency of generated THz signal is on the order of 0.63 × 10-5%. Copyright © 2019 American Chemical Society.

Physics

Crystal Growth & Design

Evaluation of Linear and Nonlinear Optical Properties of D−π–A Type 2-Amino-5-Nitropyridinium Dihydrogen Phosphate (2A5NPDP) Single Crystal Grown by the Modified Sankaranarayanan–Ramasamy (SR) Method for Terahertz Generation

This paper provides the efficient and economical moment connection details of a cold formed tubular beam column end plate joint with different arrangemet of long bolts. Totally nine models are created and analysed using the finite element software ANSYS APDL. The size of the beam and column sections used is 700 mm x 50 mm x 100 mm and 900 mm x 50 mm x 100 mm, respectively. The thickness of the section is 2.0 mm. The end plate size is 100mm x 150mm x 2.5mm and 6 mm diameter long bolts are used to connect the members in the joint. The performance of end plate and long bolts during the loading is investigated. For validation, one of the models is tested to failure and found satisfactory. The results of the analysis show that the end plate deformation in tension zone is reduced by adding more number of bolts and the symmetrical arrangement of long bolts increase the rigidity of the joint and prevent the detachment of end plate from column face. The models HS2.5P-6 and HS2.5P-9 show almost similar behaviour in terms of moment-rotation and therefeore from economic design and fabrication point of view the model HS2.5P-6 may be considered as the best suitable connection. © IAEME.

International Journal of Civil Engineering and Technology

Long bolted end-plate moment connections

This paper describes the design and numerical simulation of a highly efficient broadband antenna on stretchable substrate. The reversibly deformable and stretchable antenna proposed here uses the stretchable fabric Lycra which is known for its exceptional elasticity. The DGS mentioned in this antenna helps to achieve broadband operation of 23.8% in 10dB impedance bandwidth with enhanced efficiency of 97.389% with the size reduction of 40.06%. In general, textiles present a very low dielectric constant that reduces the surface wave losses and increases the impedance bandwidth of the antenna. Multiway stretchable fabric helps to achieve multiple frequency bands. Hence the more stretchable lycra fabric is used here. The radiation characteristics of the designed antenna are analyzed for variation in number of slots and different levels of stretchability. The proposed design for various stretchablilty levels are simulated using HFSS EM simulation software and the results are discussed. This antenna is meant to be utilized for S and C (2 to 6 GHz) band wireless applications. © 2018 National Institute of Optoelectronics. All Rights Reserved.

Lycra fabric as an effective stretchable substrate for a compact highly efficient reversibly deformable broadband patch antenna

Bulk size 4-methyl benzophenone (4MB) single crystals have been grown by Czochralski method in a period of 8 h. The unit cell parameters of the grown crystals were confirmed by single crystal X-ray diffraction analysis. The lower UV cut-off wavelength of 4MB crystal was studied by UV–Vis NIR spectrum analysis and the cut-off wavelength was found to be 379 nm. The FTIR spectrum confirms the presence of different functional groups present in the crystal. The luminescence properties of 4MB single crystal were described by Photoluminescence spectra. Thermal stability, material decomposition and melting point of the grown crystals were determined by Thermogravimetric/differential thermal analysis measurements. The mechanical stability of the 4MB single crystal was examined using Vickers microhardness test and it was found that the crystal belongs to soft material category. Laser damage threshold measurement was carried out by using Nd:YAG laser. The nonlinear refractive index, nonlinear absorption coefficient and third order nonlinear susceptibility were measured from Z-Scan measurements. The density functional theory calculations for isolated 4MB molecule were performed with B3LYP/6-311 + + G(d,p) level. The electronic properties and polarizabilities of title molecule were calculated. © 2018, Springer Science+Business Media, LLC, part of Springer Nature.

Electronics

Journal of Materials Science: Materials in Electronics

Investigations on 4-methyl benzophenone (4MB) single crystal grown by Czochralski method and its characterization

The use of steel structures has been increasing in the world as they are more efficient and effective with high stiffness and strength. In order to achieve more strength and stiffness steel beams with corrugated web are widely used due to their light weight and high load carrying capacity. In the present research, corrugated sheets of different thicknesses, different corrugated angle and different shape of corrugated sheets are used to make a corrugated web beam. The connections between flanges and web can be either by self-drilling screws or by welding. The flexural behavior of those beams are studied in Ansys and reported here in this paper. The load carrying capacity of each beam is determined and the optimum corrugated angle and shape are found. Deformations and stress distribution are displayed. Failure modes are also determined. © IAEME Publication.

A study on flexural capacity of steel beams with corrugated web

As the development today includes the consideration of having fewer disturbances and more economic, curves in flyovers or bridges are an obvious attempt to maintain it. Curved girders are mostly provided in steel in India as it is more economical as compared to steel. The curvature of the bridge can be varied as required but in some cases there are no options due to the surrounding restrictions. There are various types of steel girders that can be provided at curves, I girders and Box girders are the most common among them. In this paper the detail analytical study of both the types will be carried with an objective to find which type of cross section is suitable in which case to be more economical. The design of bridges depends mainly on the radius of curvature and the diaphragm spacing in case of curved girder especially. In this paper, models of box girder and I girder bridges are created in MIDAS Civil software which is found to give very accurate results. The models are made with varying radius of curvature and bracing spacing to study their influence in the analysis results. Torsion study will be the main area of research in this paper. The results will be studied and the conclusion will be drawn and also the most economical design and the type of bridge for curves. © IAEME Publication.