Indian Institute of Technology Palakkad&nbsp;(IIT Palakkad or IIT PKD) is a public autonomous&nbsp;engineering&nbsp;and&nbsp;research&nbsp;institute located in&nbsp;Palakkad,&nbsp;Kerala. It was&nbsp;one of the five new&nbsp;IITs&nbsp;proposed in the&nbsp;2014 Union budget of India. The campus was inaugurated on 3 August 2015. The institute has 94 faculty, 978 students, and 63 non-teaching staffs.

IT Palakkad currently offers four-year Bachelor of Technology (B.Tech) and two years MS programmes in 8 different engineering disciplines including&nbsp;Computer Science, Electrical, Mechanical, Civil among others.

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IIT Palakkad

Friction coefficient between a circular-disk periphery and V-block surface was determined by introducing the concept of isotropic point (IP) in isochromatic field of the disk under three-point symmetric loading. IP position on the symmetry axis depends on active coefficient of friction during experiment. We extend this work to asymmetric loading of circular disk in which case two frictional contact pairs out of three loading contacts, independently control the unconstrained IP location. Photoelastic experiment is conducted on particular case of asymmetric three-point loading of circular disk. Basics of digital image processing are used to extract few essential parameters from experimental image, particularly IP location. Analytical solution by Flamant for half plane with a concentrated load, is utilized to derive stress components for required loading configurations of the disk. IP is observed, in analytical simulations of three-point asymmetric normal loading, to move from vertical axis to the boundary along an ellipse-like curve. When friction is included in the analysis, IP approaches the center with increase in loading friction and it goes away with increase in support friction. With all these insights, using experimental IP information, friction angles at three contact pairs of circular disk under asymmetric loading, are determined. © 2015 SPIE.

Department of Mechanical Engineering

World University root node

Proceedings of SPIE - The International Society for Optical Engineering

Characterization of friction at three contact pairs by photoelastic isotropic point (IP)

Application of innovative smart control technology is becoming increasingly popular among researchers and practitioners particularly for a structure under wind or seismic excitation. However, the active control technology for a structure subjected to an underground blast loading has not been done so far. A typical blast-induced loading generates high frequency waves (having a very short duration with large amplitude acceleration) that significantly excite the high frequency modes of a structure during the forced regime. However, the transient part of the structural response is governed by the low frequency modes of the structure. As a result, the structure first suffers large floor acceleration responses followed by a large displacement response. In this study two algorithms, namely, pole placement and LQG control are used in order to control both the displacement and acceleration of a three-story building. For active conrod mechanism, a real time single input force is applied through an actuator. The performance of the system under these control methodologies is then compared to judge the suitability and effectiveness of a smart control scheme over widely used passive controlled system. © Springer India 2015. All rights reserved.

Department of Civil Engineering

Advances in Structural Engineering: Mechanics, Volume One

Control of blast-induced vibration of building by pole placement and LQG control algorithm

Abstract The main objective of this study was to develop, derive, and estimate the phase angle (Pdbl) parameter from resilient modulus (Mr) test, designated PdblMr, at various temperatures and frequencies for eleven types of asphalt mixtures: two conventional dense-graded (DGAC), four polymer-modified gap-graded (P-Gap), four asphalt-rubber gap-graded (AR-Gap), and one asphalt-rubber open-graded (AR-Open) mix. PdblMr were estimated for the eleven mixes with three replicates per mix totalling 33 samples at 15, 25 and 35 C and at 0.5, 1, and 1.5 Hz. AR-Open mixes had the highest PdblMr followed by AR-Gap and P-Gap, and then followed by DGAC mixes. Principally, with an increase in the asphalt content from conventional to modified mixes, there was an increase in PdblMr, suggestive of the fact that the mixes that had higher asphalt contents have extra-viscous response or are highly viscoelastic. Furthermore, PdblMr predictive model was developed based on asphalt material properties totalling 99 data points provided by R2adj (adjusted coefficient of estimation) = 0.8390, and Se/Sy (ratio of standard error to standard deviation indicative of relative accuracy of the predictive model) = 0.3820; depicting very good correlation between the estimated and predicted ∅Mr, and with low bias and high precision. Additionally, PdblMr master curves were constructed for the mixes with 35 C as reference. Overall, it is envisioned that PdblMr parameter obtained in this study will be helpful to comprehensively understand the viscoelastic properties of different asphalt mixtures, and incorporate PdblMr as a viscoelastic characteristic assessor in futuristic flexible pavement designs. © 2015 Elsevier Ltd. All rights reserved.

Construction and Building Materials

Estimation of phase angles of asphalt mixtures using resilient modulus test

We develop an integrated framework to determine and compare greenhouse gas (GHG) intensities and production costs of cellulosic ethanol derived from corn stover, switchgrass, and miscanthus grown on high and low quality soils for three representative counties in the Eastern United States. This information is critical for assessing the cost-effectiveness of utilizing cellulosic ethanol for mitigating GHG emissions and designing appropriate policy incentives to support cellulosic ethanol production nationwide. We find considerable variations in the GHG intensities and production costs of ethanol across feedstocks and locations mostly due to differences in yields and soil characteristics. As compared to gasoline, the GHG savings from miscanthus-based ethanol ranged between 130% and 156% whereas that from switchgrass ranged between 97% and 135%. The corresponding range for GHG savings with corn stover was 57% to 95% and marginally below the threshold of at least 60% for biofuels classified as cellulosic biofuels under the Renewable Fuels Standard. Estimates of the costs of producing ethanol relative to gasoline imply an abatement cost of at least $48 Mg-1 of GHG emissions (carbon dioxide equivalent) abated and can be used to infer the minimum carbon tax rate needed to induce consumption of cellulosic ethanol. © 2015 American Chemical Society.

Environmental Sciences and Sustainable Engineering Centre (ESSENCE)

Environmental Science and Technology

Cost of abating greenhouse gas emissions with cellulosic ethanol

In this paper, by augmenting beamforming with signal nulling, we present a scheme to improve the equivocation in wireless relay networks. Assuming global channel state information, memoryless adversaries, and the decode-and-forward relaying strategy, we seek to maximize the average achievable secrecy rate between the source and the legitimate destination, subject to an overall power budget per message. Then, exploiting the structure of the optimization problem, we present an online sequential approach to compute an achievable average rate. Finally, we use numerical evaluations to compare our method with the conventional schemes. © 2015 IFIP.

Department of Computer Science and Engineering

2015 13th International Symposium on Modeling and Optimization in Mobile, Ad Hoc, and Wireless Networks, WiOpt 2015

Beating resource constrained eavesdroppers: A physical layer security study

In rolling contact bearings, contact occurs between the rolling surfaces over a small region. Hence, high contact stresses are induced in the region even under a small load. These stresses are cyclic in nature. Over a long period of time, the surface gets fatigued and surface fatigue wear ensues. The experimental investigation carried out in the laboratory earlier consumed a long time. Therefore, a numerical approach is resorted to in this paper. To study this aspect, the stress field in the contact surface region is analyzed under elastohydrodynamic lubrication with line contact considering the friction effect. The bearing steel microstructure is considered as a mixture of martensite and retained austenite having entirely different mechanical properties and yield behavior. Using finite element analysis, the stress field has been evaluated taking into account two volumetric fractions (8% and 20%) of retained austenite in heat treated AISI 52100 bearing steel. A simplified approach neglecting the effect of strain induced transformation of austenite is attempted in the first phase. The depth at which the failure is expected to occur is compared with the experimental values of earlier investigation. The predicted values are marginally higher than the experimental values. © 2015 Elsevier B.V.

Wear

Numerical evaluation of subsurface stress field under elastohydrodynamic line contact for AISI 52100 bearing steel with retained austenite

A computational framework based on a combined 3D-CFD/FE along with a second order rotor dynamics model is employed to assess a six-tooth straight through rotating labyrinth seal for a varying flow and operating conditions. Three-dimensional Reynolds Averaged Navier-Stokes compressible equations are solved to obtain the circumferential pressure distributions and are integrated further to calculate the seal fluid forces. Subsequently, the extracted rotor dynamic coefficients are compared to the one without considering centrifugal growth. All the six rotor dynamic coefficients shows distinct characteristics when the centrifugal growth is accounted for. The centrifugal growth has a substantial reduction on cross-coupled stiffness and direct damping and the influence increases with speed. The stability aspects of the seal are examined in terms of whirl frequency ratio and effective damping coefficient, presuming synchronous whirl. The results emphasis the consideration of the seal centrifugal growth effects, while conducting rotor dynamic stability analysis for a typical rotor system.

22nd International Congress on Sound and Vibration, ICSV 2015

Influence of centrifugal growth on the rotor dynamic stability of a rotating labyrinth seal

Department of Physics

Physical Review E - Statistical, Nonlinear, and Soft Matter Physics

Erratum: Effects of aging in catastrophe on the steady state and dynamics of a microtubule population (Physical Review E - Statistical, Nonlinear, and Soft Matter Physics 91, 052704 (2015))

The following results are proved. The Null Space TheoremLet X,Y be vector spaces, P∈L(X),Q∈L(Y) be projections and T∈L(X,Y) be invertible. (The restriction of QTP to R(P) can be viewed as a linear operator from R(P) to R(Q). This is called a section of T by P and Q and will be denoted by TP,Q.) Then there is a linear bijection between the null space of the section TP,Q of T and the null space of its complementary section TIY-Q,IX-P-1 of T-1. Let X be a Banach space with a Schauder basis A={a1,a2,⋯}. Let T be a bounded (continuous) linear operator on X. Suppose the matrix of T with respect to A is tridiagonal. If T is invertible, then every submatrix of the matrix of T-1 with respect to A that lies on or above the main diagonal (or on or below the main diagonal) is of rank ≤1. © 2015 Elsevier Inc. All rights reserved.