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Narayanan S.,Indian Institute of Technology Madras | Balamurugan V.,Center for Engineering Analysis and Design
IUTAM Bookseries

A nine-noded piezolaminated shell element with functionally graded material (FGM) is formulated based on the volume fraction power law distribution. One side of the FGM is assumed to be metal rich while the other side to be ceramic rich. Active vibration control capability of FGM plates and shells with attached PZT layers as integrated sensors/actuators to suddenly applied pressure loads and random excitation is investigated using the LQR optimal control scheme for different volume fraction power law exponents. © 2010 Springer Science+Business Media B.V. Source

Balamurugan V.,Center for Engineering Analysis and Design | Narayanan S.,Indian Institute of Technology Madras
Smart Materials and Structures

In this paper, a piezolaminated stiffened shell element is formulated. This piezoelectric shell element is a 9-noded, isoparametric, shear flexible and field-consistent element with five elastic degrees of freedom at each node and one electric degree of freedom per element per piezoelectric layer. The stiffener element is a three-noded isoparametric beam element with three degrees of freedom at each node. The effect of the stiffener is incorporated by internally constraining the stiffener displacement fields to the relevant shell displacement fields and hence this formulation allows the positioning of the stiffener element anywhere within the shell element along lines of natural coordinates, which gives a great flexibility in the choice of the mesh size. This stiffened shell element is validated for static deflection and dynamic response with the results available in literature. The active control performance of the stiffened composite plate and shell structures with distributed piezoelectric sensors and actuators are studied using a number of examples. The active vibration control is carried out using the LQR optimal control. © 2010 IOP Publishing Ltd. Source

Banerjee S.,Center for Engineering Analysis and Design | Balamurugan V.,Center for Engineering Analysis and Design | Krishnakumar R.,Indian Institute of Technology Madras
Journal of Terramechanics

Tracked vehicles are exposed to severe ride environment due to dynamic terrain-vehicle interactions. Hence it is essential to understand the vibration levels transmitted to the vehicle, as it negotiates different types of terrains at different speeds. The present study is focused on the development of single station representation of tracked vehicles with trailing arm hydro-gas suspension systems, simulating the ride dynamics. The kinematics of hydro-gas suspension system have been derived in order to determine the non-linear stiffness characteristics at various charging pressures. Then, incorporating the actual suspension kinematics, non-linear governing equations of motion have been derived for the sprung and unsprung masses and solved by coding in Matlab. Effect of suspension non-linear dynamics on the single station ride vibrations have been analyzed and validated with a multi-body dynamics model developed using MSC.ADAMS. The above mathematical models would help in estimating the ride vibration levels of the tracked vehicle, negotiating different types of terrains at various speeds and also enable the designers to fine-tune the suspension characteristics such that the ride vibrations are within acceptable limits. The mathematical ride model would also assist in development of non-linear ride vibration model of full tracked vehicle and estimate the sprung mass dynamics. © 2014 ISTVS. Published by Elsevier Ltd. All rights reserved. Source

Srinivasan K.,Indian Institute of Technology Madras | Srinivasan K.,Center for Engineering Analysis and Design | Balamurugan V.,Center for Engineering Analysis and Design | Jayanti S.,Indian Institute of Technology Madras
Engineering Optimization

Iterative search methods, such as the Box complex method, can be used for inverse shape design problems. In the present article, an improved version of the Box complex method is proposed specifically for computational fluid dynamics-based optimization of fluid flow ducting elements. The original Box complex method is improved by (1) assigning non-uniform weights for the estimation of the centroid, (2) using a reduced reflection factor for accelerated convergence, and (3) introducing measures to prevent premature breakdown of the iterative process. The success of the improved Box complex method over the original Box complex method is demonstrated on two benchmark functions and by applying it to two fluid flow problems of engineering. The improved method is shown to substantially accelerate the convergence with approximately 50% reduction in computational effort for the T-junction and manifold problems. © 2016 Informa UK Limited, trading as Taylor & Francis Group Source

Venkateswaran N.,Center for Engineering Analysis and Design | Vinobakrishnan R.,Center for Engineering Analysis and Design | Balamurugan V.,Center for Engineering Analysis and Design
SAE Technical Papers

This paper deals with the Coupled thermo mechanical analysis of a cylinder head, cylinder block and crank case with the liner of an uprated engine. The existing engine develops 780 hp output with mechanical driven supercharger and the engine is uprated to 1000 hp by replacing the supercharger with a turbocharger and new Fuel injection equipment. For uprating any engine, the piston and cylinder head are the most vulnerable members due to increased mechanical and thermal loadings. Mechanical loading is due to the gas pressure in the gas chamber and its magnitude can be judged in terms of peak pressure. Thermal loading is due to temperature and the heat transfer conditions in the piston surface, cylinder liner and the cylinder head. The relative importance of the various loads applied on the head and cylinder block in operation are assessed and a method of predicting their influence on the structural integrity of the components described. The Cylinder head, cylinder block and crank case of the uprated Engine have been modeled using finite element method and coupled steady state heat transfer cum thermal stress analysis has been done. The present study concentrates on the peak conditions such as peak firing pressure and steady state thermal conditions. This study shows that the cylinder head and cylinder block can withstand the higher stresses due to enhanced pressure and thermal loads in the uprated version of the engine and no further design modifications are necessary. And it is also observed from the successful completion of Endurance and Performance evaluation of this uprated engine in the test bed, as well as in the vehicle. Copyright © 2011 SAE International. Source

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