Faculty Publications
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Publications by NITK Faculty
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Item Effect of Soil-Structure Interaction on the Seismic Response of Elevated Water Tank(Springer Science and Business Media Deutschland GmbH, 2022) Jogi, J.; Jayalekshmi, B.R.The elevated tanks are the most critical and strategic structures since the tank contains heavy fluid mass and is placed on a slender staging. The foundation transmits the loads from the superstructure to the subsoil, and the displacement of the soil influences the response of the structure. Therefore, it is important to study the seismic response of liquid storage tanks with the incorporation of soil-structure interaction (SSI). This study aims to find the importance of the effects of supporting soil medium in the response of the water tanks. An elevated intze water tank of capacity 7,00,000 L on frame type staging was modeled and analyzed by considering SSI in finite element software ANSYS. To incorporate the effect of SSI, rock, dense, stiff, and soft supporting soil strata were considered. The infinite extent of soil was modeled using viscous boundaries. The transient analysis was carried out for the 3D liquid tank models with different supporting soils using Kobe earthquake data. The base shear, base moment, and structural displacements were found with the variation of depth of fluid inside the tank for all the models. The results showed that the maximum base shear and the base moment were observed in a tank resting on hard soil for the completely filled condition of liquid. The displacements are higher in the case of tanks resting on soft soil. © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.Item Sloshing Response of Water Tanks Under Seismic Excitation(Springer Science and Business Media Deutschland GmbH, 2022) Jogi, J.; Jayalekshmi, B.R.Liquid storage tanks are the predominant structures and they have to be designed to withstand major earthquake loads. In the present study, an elevated intze water tank of capacity 700 m3 was considered and analyzed for seismic effects. Finite element modeling of the tank was made in ANSYS. A series of transient analyses was carried out for El Centro and Kobe earthquakes which are applied in the horizontal direction. The fluid inside the tank accelerates and causes additional hydrodynamic pressures on the tank. Past studies reveal that the convective hydrodynamic pressure is more than the impulsive hydrodynamic pressure. Time history plots were made to describe the sloshing phenomenon in the tank for various levels of the liquid. The sloshing displacements for the one-third level of the liquid were found to be maximum. The sloshing displacements in the horizontal direction are more than in the vertical direction. © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.Item Development of Pneumatic Soft Gripper for Effective Material Handling(Institute of Electrical and Electronics Engineers Inc., 2024) Naveen, S.; Panigrahi, S.; Vinit, A.; Sudar, I.H.; Thomas, M.J.Recent times have shown a drastic transition in robotics from rigid to soft mechanisms. The reason is that soft robots offer safer human-robot interactions, reduce weight and also offer strong environmental adaptability. However, the inherent characteristics of soft materials to exhibit multiple degrees of freedom (DoF) make it challenging to control their movements. Therefore, this paper presents the development of a soft gripper with simple architecture to effectively and economically manipulate delicate objects. The gripper constructed using silicon rubber has an air cavity to actuate its opening and closing pneumatically. This paper presents the different stages of its construction and demonstrates its application on a 4 DoF robotic arm for handling delicate objects. A simulation study of the structural parameters of the proposed soft gripper is also carried out using ANSYS finite element software. The preliminary results show the superior adaptability of the soft gripper in handling objects of various shapes and sizes. The proposed system can find application in food, biomedical and electronic industries. © 2024 IEEE.Item Modal and random vibration analysis of pneumatic actuator of wastegate turbocharger using finite element method(Association of American Publishers, 2025) Patkar, R.; Joladarashi, S.Turbocharging is the most common power augmentation method used in both spark and compression ignition engines. However, the excessive turbo boost can end up in risking the intake manifold pressure which can negatively affect the performance of an engine. Therefore, the modern turbochargers are developed with wastegate which effectively controls the turbine speed and limits the excessive turbo boost bypassing the fraction of exhaust gas. In this work, the modal and random vibration analysis of the pneumatic actuator assembly of a wastegate turbocharger is presented. The turbocharger was substituted by a dummy vibratory shaker table with test spacers and a subassembly was mounted on the shaker table. The model of the actuator was designed in Creo© software and finite element analysis was performed in the commercially available software package ANSYS©. The materials used for critical components of the assembly were Structural Steel and SAE1008 Steel for the bracket and CAN respectively. Initially the structural load in the form of bolt pretension was applied at bolted joints and prestressed modal analysis was performed. The results of modal analysis were further utilized for random vibration analysis. The PSD acceleration input was given to the shaker table and output response at critical locations was analyzed. Subsequently, the results were quantitatively analyzed for modal participation factor variation, natural frequencies and PSD equivalent stresses in the actuator assembly. © 2025, Association of American Publishers. All rights reserved.Item An investigation on characteristics and free vibration analysis of laminated chopped glass fiber reinforced polyester resin composite(Asian Research Publishing Network arpn@arpnjournals.com, 2016) Allien, V.; Kumar, H.; Desai, V.In this paper material characterization and free vibration analysis of polyester resin based two, four and six layers chopped strand mat (CSM 450g/m2 specific weight) glass fiber reinforced with (CGRP) composite materials has been determined. In material characterization the tensile, flexural, impact, inter-laminar shear strength, fracture toughness has been evaluated. The results have revealed that, the four layer CGRP composite material has high impact, inter laminar shear strength and fracture toughness compared to two and six layers composite material. Free vibration analysis was carried out to determine the natural frequency of the CGRP composite materials theoretically and numerically (FEA). The result obtained from free vibration analysis indicated that natural frequency of six layers CGRP composite material is more than two and four layers CGRP composite material. © 2006-2016 Asian Research Publishing Network (ARPN).Item Computational analysis of unsteady flow in turbine part of turbocharger(Springer Heidelberg, 2017) Rao, H.K.S.; Raviteja, S.; Kumar, G.N.Turbocharging technique is widely employed in internal combustion engines to improve the performance and to reduce the exhaust emissions. Flow analysis through the turbocharger has been a guiding method to optimize the turbocharger design. Usually, the turbocharger turbine is analyzed at steady states. But in practical scenario the turbine operates with unsteady flow due to the reciprocating motion of exhaust port and creates unsteady environment in the turbine. In order to increase turbine efficiencies and effective engine turbocharger matching, proper understanding of unsteady flow physics within the turbine is essential. Currently the turbine and compressors maps are obtained by using 1D code which includes extrapolation techniques. These methods neglect heat transfer and windage effects, hence resulting in lower aerodynamic efficiencies. Three dimensional analysis could lead to a better estimation of the flow field, helping the designer to build a high efficiency turbocharger. The present article concentrates on investigating unsteady flow field in the turbine part of a turbocharger. The necessary unsteady conditions at turbine inlet were obtained using commercially available one dimensional engine simulation software AVL Boost. A turbocharged twin cylinder CRDI diesel engine test rig was modelled within the workspace. The exhaust mass flow rate, pressure and temperature were recorded as a function of crank angle. These results were used as the boundary condition for the 3D analysis of the turbine. ANSYS CFX tools were used to solve the unsteady case. The turbine geometry was generated using ANSYS bladegen. The model selected for analysis is k-? turbulence Model. The pulsating performance, effect of secondary flows and entropy generation are discussed in the paper. © Springer India 2017.Item Comparison of the Experimental and Modelling Results of Mechanical Characteristics of LM6 and LM9 Alloy for Tractor Application(Springer, 2023) Shetteppanavar, C.C.; Shinde, R.B.; Hanumanthappa, H.; Mohanraj, G.T.; Shanmugam, B.K.S.; Srivatsav, S.K.Y.; Kavitha Kumar, A.R.B.K.In India, the development of composite and alloys material has provided the required characteristics material. In this study, an attempt has been made to compare the performance of LM6 and LM9 alloy for an automobile application. These alloys are studied based on the tensile strength and fatigue test required for the pullet used in tractor application. The tensile test results showed that the LM9 alloy specimen has higher strength than the LM6 alloy specimen. Furthermore, results showed that the fatigue strength of the LM9 alloy specimen was found to be higher than the LM6 alloy specimen. Further, the tensile and fatigue materials behaviour of LM6 and LM9 specimens were compared through ANSYS modelling. From the experimental and modelling results, it was clear that the modelling results are in close agreement with the tensile and fatigue experimental results. The mechanical characteristics such as tensile and fatigue strength of the LM9 specimen were found to be much better than the LM6 specimen. The microstructural analysis also showed higher silicon particles providing higher strength for LM9 specimens than LM6 specimens. The pulley material made out of LM9 alloy will avoid the shear failure occurrence of the pulley. © 2022, The Institution of Engineers (India).Item Structural and modal analysis of crankcase of single cylinder diesel engine(Springer-Verlag Italia s.r.l., 2023) Dhummansure, V.; Doddamani, S.; Jamadar, N.I.; Mohamed Kaleemulla, K.Among the most critical components, crankcase the housing for the crankshaft is used for effective and precise working of the internal combustion engine. The main aim of this work is to analyze the structural and modal parameters of the crankcase of diesel engine of existing and modified model. Solid model of the crankcase is generated using the commercially available software packages, as per the dimensional details of existing crankcase. Static and vibrational analysis of the crankcase is carried out using commercially available software packages for the boundary conditions in accordance with engine specifications and mounting conditions. The modified model of the crankcase is also modeled, analyzed and compared with the existing model of the crankcase. The modified model is prepared for the experimentation using the fast fourier transformer (FFT) analyzer. Simulation results show that the modified model of the crankcase demonstrates the reduced stresses (by 10%) and deformation by (40%) with the existing model also absorb more vibrations. © 2022, The Author(s), under exclusive licence to Springer-Verlag France SAS, part of Springer Nature.Item A Numerical Study on Coconut Inflorescence Stem-Fiber-Reinforced Panels Subjected to Tensile Load, Compressive Load, and Flexural Load(Multidisciplinary Digital Publishing Institute (MDPI), 2024) Muralidhar, M.; Mahadevaiah, R.R.; Parshuram, K.R.B.; Hiremath, P.Natural-fiber-reinforced composites are attracting an increasing amount of interest, and they are becoming more popular as a replacement for synthetic-fiber-reinforced composites. Natural-fiber-reinforced composites are important as a potential building material due to their lightweight nature, strength, and favorable qualities, which include eco-friendliness, non-toxicity, and biodegrad-ability. Natural fibers such as hemp fibers, jute fibers, banana fibers, coconut fibers, sisal fibers, bamboo fibers, areca nut fibers, and kenaf fibers have been used for making composite panels be-cause of their strength-to-weight ratio. Coconut inflorescence stem fibers are considered for our study. Coconut inflorescence stem-reinforced composite panels are often subjected to tensile load, compression load, and flexural load. Tensile strength, compressive strength, and flexural strength play a vital role when these panels are subjected to service loads. In this context, finite element analysis (FEA) is carried out on coconut inflorescence stem-reinforced panels subjected to tensile load, compressive load, and flexural load. A linear analysis is performed for the mechanical properties by using ANSYS workbench 2021 R1. A coconut inflorescence stem-reinforced composite specimen with the dimensions 280 mm × 25 mm × 3 mm (length × width × thickness) for tensile loading, 145 mm × 25 mm × 4 mm for the compressive load, and 150 mm × 25 mm × 4 mm for the flexural load is considered for the present study, as per the ASTM-D3039, ASTM-D3410, and ASTM-D790 standards, respectively. Finite element analysis results showed good correlation with the analytical results. © 2024 by the authors.