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

The objective of this work is to find cumulative fatigue damage of the truck cabin caused by proving ground data. Stresses in the cabin are derived by finite element analysis using inertia relief method. Multi body simulation software ADAMS was used to obtain the load history at cabin attachment points using measured proving ground data as input. The fatigue damage of the truck cabin was estimated by linear super position method with static results and load history. The calculated numerical fatigue damage results were compared with physical test results and correlated. © 2013 SAE International.

World University root node

Department of Electrical Engineering

SAE Technical Papers

Virtual durability analysis of heavy commercial truck cabin for proving ground inputs

Evaluation of vehicle structural durability is one of the key requirements in design and development of today's automobiles. Computer simulations are used to estimate vehicle durability to save the cost and time required for building and testing the prototype vehicles. The objective of this work was to find the service life of automotive structures like passenger commercial vehicle (bus) and truck's cabin by calculating cumulative fatigue life for operation under actual road conditions. Stresses in the bus and cabin are derived by means of performing finite element analysis using inertia relief method. Multi body dynamics simulation software ADAMS was used to obtain the load history at the bus and cabin mount locations-using measured load data as input. Strain based fatigue life analysis was carried out in MSC-Fatigue using static stresses from Nastran and extracted force histories from ADAMS. The estimated fatigue life was compared with the physical test results. Copyright © 2013 SAE International and Copyright © 2013 SIAT, India.

Structural fatigue strength evaluation of commercial vehicle structures by calculating damage due to road load inputs

Phosphorus (P) indices, originally developed to assess the risk of P export to aquatic systems from agricultural fields receiving inorganic fertilizers and livestock manures, are being used for other P sources with different characteristics and methods of application. This study determined Pennsylvania P index scores for eleven crop fields of Penn State University's Living Filter system receiving 130 kg P2O5 ha-1 (115 lb P2O5 ac-1) in 2008 via sprinkler irrigation of municipal wastewater effluent. A baseline assessment of P index treated effluent irrigation as surface application of completely soluble P source material with maximum potential of runoff P loss. Three fields located ≤22 m (200 ft) from streams ranked high and very high in P loss rating under baseline assessment. Modified assessments involved changing the application method multiplier and P source coefficient to more accurately reflect the year-round intermittent application of P via sprinkler irrigation. All fields were ranked as having low risk of P export using the modified parameters. Site monitoring data from nearly 50 years of effluent irrigation show no evidence of excess P transport to groundwater or off-site surface water, suggesting that baseline assessment might be overestimating P loss rating of some fields. Results underscore the need to tailor P indexing tools to address the differential risk of P loss for specific P sources and application methods. Copyright © 2013 Soil and Water Conservation Society.

Environmental Sciences and Sustainable Engineering Centre (ESSENCE)

Journal of Soil and Water Conservation

Applicability of phosphorus site indices to wastewater effluent-irrigated cropland

We consider the problem-Δpu = aup-1-bu γ -1-c/uα, x ∈Ω, u = 0, x ∈ ∂Ω, whereΔpu = div(|∇u|p-2∇u) , p &gt; 1, Ω is a smooth bounded domain in ℝn, a &gt; 0, b &gt; 0, c ≥ 0, γ &gt; p and α ∈ (0, 1). Given a, b, γ and α, we establish the existence of apositive solution for small values of c. These results are also extended to corresponding exterior domain problems. Also, a bifurcation result for the case c = 0 ispresented. © 2013 Goddard II et al.

Department of Mathematics

Fulltext

Boundary Value Problems

Existence results for classes of infinite semipositone problems

Edge cracked semicircular disk under compression exhibited form factor constancy over wide range of relative crack lengths. Inspired from this property, edge cracked semicircular ring (ECSR) is analyzed with the aim of enhancing validity range of constant form factor property. Understanding the effects of inner radius and load angle on form factor of ECSR, different combinations of the two are examined towards reaching the aim. Photoelasticity in conjunction with FEM is used to analyze the specimen. A particular combination of inner radius and load angle is found to give constant form factor over an enhanced range.

Department of Mechanical Engineering

Indian Conference on Applied Mechanics, Indian Institute of Technology {\ldots}

A novel semicircular compression fracture specimen

The longevity of a large number of reinforced concrete bridge piers has been compromised as a result of Alkali-Silica Reaction (ASR) and Delayed Ettringite Formation (DEF). These structures need to be assessed for strength and performance to ensure their general load capacity and safety. It is shown that present code-based methods of analysis, whether they be the sectional method or strut-and-tie methods, are unable to discriminate between these concrete elements without and with the effects of ASR/DEF. A Compatibility Strut-and-Tie Modeling (C-STM) technique is therefore used. Prestress forces are applied at certain truss nodes to mimic the swelling effects of ASR/DEF damage to the concrete. The computational C-STM approach is verified against several large-scale experimental tests. It is observed that the C-STM predicts the overall force-deformation behavior of the structure without and with ASR/DEF effects with good accuracy. © 2013 American Society of Civil Engineers.

Department of Civil Engineering

Structures Congress 2013: Bridging Your Passion with Your Profession - Proceedings of the 2013 Structures Congress

C-STM modeling of bridge piers without and with ASR/DEF deterioration

A rainbow colouring of a connected graph G is a colouring of the edges of G such that every pair of vertices in G is connected by at least one path in which no two edges are coloured the same. The minimum number of colours required to rainbow colour G is called its rainbow connection number. Chakraborty, Fischer, Matsliah and Yuster have shown that it is NP-hard to compute the rainbow connection number of graphs [J. Comb. Optim., 2011]. Basavaraju, Chandran, Rajendraprasad and Ramaswamy have reported an (r + 3)-factor approximation algorithm to rainbow colour any graph of radius r [Graphs and Combinatorics, 2012]. In this article, we use a result of Guruswami, Hästad and Sudan on the NP-hardness of colouring a 2-colourable 4-uniform hypergraph using constantly many colours [SIAM J. Comput., 2002] to show that for every positive integer κ, it is NP-hard to distinguish between graphs with rainbow connection number 2κ + 2 and 4κ + 2. This, in turn, implies that there cannot exist a polynomial time algorithm to rainbow colour graphs with less than twice the optimum number of colours, unless P = NP. The authors have earlier shown that the rainbow connection number problem remains NPhard even when restricted to the class of chordal graphs, though in this case a 4-factor approximation algorithm is available [COCOON, 2012]. In this article, we improve upon the 4-factor approximation algorithm to design a linear-time algorithm that can rainbow colour a chordal graph G using at most 3/2 times the minimum number of colours if G is bridgeless and at most 5/2 times the minimum number of colours otherwise. Finally we show that the rainbow connection number of bridgeless chordal graphs cannot be polynomial-time approximated to a factor less than 5/4, unless P = NP. © L. Sunil Chandran and Deepak Rajendraprasad.

Department of Computer Science and Engineering

Leibniz International Proceedings in Informatics, LIPIcs

Inapproximability of rainbow colouring

This paper proposes an observer-assisted (indirect) adaptive trajectory tracking control scheme for an under-actuated autonomous underwater robotic vehicle. The proposed control algorithm was based on feedback linearization control, using the estimated vehicle (hydrodynamic) parameters and external disturbance parameters (e.g., underwater current, buoyancy variations, etc.). These parameters were estimated online by employing a well-known non-linear observer extended Kalman filter. Using these estimated parameters and estimated disturbance vector, a feedback linearization control system was constructed for an under-actuated underwater vehicle. The effectiveness of the proposed system demonstrated and discusses the robustness using simulation results. The simulation results were compared with those of a control scheme that employed true parameters and without compensation, as well and results show the proposed scheme works well. © 2013 ACM.

ACM International Conference Proceeding Series

Observer - Assisted adaptive tracking control of an underactuated autonomous underwater vehicle

In many underwater missions, it is necessary for the autonomous underwater vehicle (AUV) to be stationed at a particular position and orientation to carry out tasks like inspection, opening/closing of valves, or repair of underwater installations. The ability of an AUV to maintain its position and orientation dynamically is termed as dynamic station keeping. Being a free-floating device, dynamic station keeping is not natural to most of the AUVs. This becomes more complex when the vehicle is underactuated and is not neutrally buoyant. In this paper, the problem of dynamic station keeping of an underactuated flat-fish type AUV is analysed and a new method of station keeping is proposed with an addition of dedicated thrusters. Effect of introduction of additional thrusters on tracking performance has been analysed and a modular configuration (using retractable thrusters) is proposed to reduce its influence on tracking control. The effects of underwater current magnitudes and angle of incidences on the station keeping performance are also analyzed. A comparative analysis on power consumption during station keeping is presented to prove the effectiveness of the proposed modular configuration. © 2012 Elsevier Ltd. All rights reserved.

Ocean Engineering

Power efficient dynamic station keeping control of a flat-fish type autonomous underwater vehicle through design modifications of thruster configuration

Composite materials are broadly recognized and accepted in a variety of engineering applications due to their inherent properties such as higher stiffhess, good corrosion resistance and more importantly assisting weight reduction. Shafts made of composite materials are widely the subject of study as it incurs the advantage of the above said properties. The composite drive shafts which can give an increased natural frequency for the same length as that of the steel shaft is a potential candidate in eliminating two piece steel drive shaft. It is used as transmission shaft in marine pro-pulsion and many other applications where weight reduction is very much appreciable. The vital rotor dynamic characteristics require for any shaft system are the natural frequencies in essentially in bending and torsion modes, the response studies and the torque transmission characteristics. In this work, glass/epoxy and carbon/epoxy shafts are studied for their response behaviour using harmonic analysis. Unbalance response studies is carried out in composite shafts by developing an un-balance in the disc mass which is equal to the eccentric mass times the radius. The shafts are modeled using glass and carbon fibers with epoxy resin as the matrix material. The modeled shafts are studied with discs mounted on them. Glass, carbon and steel discs are used for the response study. The shaft and disc combinations are varied and the results are compared. The work is carried out using ANSYS. Apart from glass and carbon shafts, hybrid shafts which include both the glass and carbon fibers in a single shaft model are also used for the study. As the hybrid shafts include the advantage of both fiber materials, it is a more viable model in order to achieve characteristics to suit respective applications. The response behavior of hybrid shafts with different discs is analyzed and compared with the glass/epoxy and carbon/epoxy shafts.