Papers by Bishakh Bhattacharya
The vibrations of the tall buildings are serious concerns to both engineers and architects for th... more The vibrations of the tall buildings are serious concerns to both engineers and architects for the protection of the safety of the structure and occupant comfort. In order to mitigate the vibration, different approaches have been proposed, among which tuned mass dampers are one of the most preferable and have been widely used in practice. Instead of dissipating the vibration energy into heat waste via the viscous damping element, this article presents an approach to harvest the vibration energy from tall buildings with tuned mass dampers, by replacing the energy-dissipating element with an electromagnetic harvester. This article demonstrates that vibration mitigation and energy harvesting can be achieved simultaneously by the utilization of an electricity-generating tuned mass damper and relevant algorithms. Based on the proposed switching energy harvesting circuit, three control strategies are investigated in this article, namely, semi-active, self-powered active, and passive-matching regenerative. The functions of the energy harvesting circuit on damping force control and power regulation, as well the effectiveness of the control strategies, are illustrated by simulation. The simultaneous energy harvesting and vibration control are demonstrated, for the first time, by experiment based on a three-story building prototype with the electricity-generating tuned mass damper, which is composed of a rotational brushed direct current motor and rack–pinion mechanism.
Proceedings of …, 2000
A combined passive and active damping strategy is proposed to control vibration in structures usi... more A combined passive and active damping strategy is proposed to control vibration in structures using a combination of layers of ferro-magnetic (passive) damping and smart (active) magnetostrictive material (Terfenol-D). Two types of combined damping systems are considered viz., a ...
Composites Science and Technology, 2013
A Lead Zirconate-Titanate (PZT)/poly-dimethylsiloxane (PDMS) based flexible composite is synthesi... more A Lead Zirconate-Titanate (PZT)/poly-dimethylsiloxane (PDMS) based flexible composite is synthesized and investigated for its potential in significantly enhancing the vibration damping capability along with its tunable properties. Rheologically and functionally different PZT/PDMS composites are prepared by dispersing different volume fractions of piezoelectric soft/hard PZT and Fe particles in a cross-linked PDMS matrix. It is observed that passive damping increases with increase in the soft PZT volume fraction from 0 to 0.32. This effect becomes more prominent after poling the composite at optimum conditions. The loss factor depends on the viscoelastic properties of the PDMS, homo and hetero-particle connectivity in the composite, and polarization and localization of the PZT particles in composite. Rheological analysis of the composite shows that the material loss factor (tan d) increases linearly from $0.3 to 0.75 along with a broadening of the peak when the PZT volume fraction is increased from 0 to 0.32. Maximum structural damping (g) is obtained at 0.32 (V/V) of the soft-PZT as measured by the Oberst beam technique. This effect becomes more pronounced after a poling treatment. The X-ray diffraction results indicate that the dispersed PZT particles in PDMS matrix have the lattice parameters of a = 5.84 Ã…, c = 14.41 Ã… and (0 0 1) orientation. Further, after poling treatment, the dielectric constant and the piezoelectric coefficient (d 33 ) for soft (submicron) PZT filler particles in PDMS matrix tend to be higher than those for hard PZT. The soft PZT/PDMS composite shows better performance as a damper than the hard, PZT composite.
Acta Materialia, 2006
In this study, nanocomposite foams reinforced with different weight percentages of silicon dioxid... more In this study, nanocomposite foams reinforced with different weight percentages of silicon dioxide nanoparticles (0.25, 0.5, 0.75 and 1.0 wt%) were fabricated using the ultrasonic and stir casting techniques. For this purpose heat treated TiH 2 was used as foaming agent. Microstructural studies were done by optical microscope and scanning electron microscope. Hardness evaluation of precursor nanocomposites showed that the hardness was significantly increased by the addition of SiO 2 nanoparticles and Al-0.75 wt% SiO 2 nanocomposite makes the highest hardness. Evaluation of compressive behavior of Al-SiO 2 nanocomposite foams showed that the plateau stress increases more than 3 times as the foam relative density increases from 0.09 to 0.16. Energy absorption of Al-SiO 2 nanocomposite foams has been found to be dependent on both relative density and structural properties.
IEEE Transactions on Systems, Man, and Cybernetics: Systems, 2015
Robot gripper design is an active research area due to its wide spread applicability in automatio... more Robot gripper design is an active research area due to its wide spread applicability in automation, especially for high-precision micro-machining. This paper deals with a multiobjective optimization problem which is nonlinear, multimodal, and originally formulated. The previous work, however, had treated the actuator as a blackbox. The system model has been modified by integrating an actuator model into the robotic gripper problem. A generic actuation system (for example, a voice coil actuator) which generates force proportional to the applied voltage is considered. The actuating system is modeled as a stack consisting of the individual actuator elements arranged in series and parallel arrays in four different combinations. With the incorporation of voltage into the problem, which is related to both actuator force and manipulator displacement, the problem becomes more realistic and can be integrated with many reallife gripper simulations. Multiobjective evolutionary algorithm is used to solve the modified biobjective problem and to optimally find the dimensions of links and the joint angle of a robot gripper. A force voltage relationship can be obtained from each of the nondominated solutions which helps the user to determine the voltage to be applied depending on the application. An innovization study is further carried out to find suitable relationships between the decision variables and the objective functions.
Proceedings of SPIE - The International Society for Optical Engineering
Vibration reduction possibilities in laminated composite with one of the plies as actuation layer... more Vibration reduction possibilities in laminated composite with one of the plies as actuation layer, have been investigated. Magnetostrictive and piezoelectric actuation have been considered. A comparative assessment of the vibration suppression performance of ...
The Journal of the Acoustical Society of America
SMART STRUCTURES AND SYSTEMS
International Journal of COMADEM
The ribbon reinforced composites are widely used in prosthetics -for example, in the field of ort... more The ribbon reinforced composites are widely used in prosthetics -for example, in the field of orthodontics where canine to canine retention is carried out with the help of resin composite retainers reinforced with Polyethylene/Kevlar ribbons. These structures typically work like a bridge between the canines. They are subjected to central loading as well as support yielding due to unequal movement of the of the end supports. However, due to the high strain in the laminate, the chances of delamination and laminate failures are quite high in such structures. The present work has proposed a high precision piezoelectric finite element which can be used with a piezoelectric sensory network to identify a damage signal and help in early replacement of the bridge. In order to identify the damage the voltage profile and mechanical impedance are obtained for healthy and damaged laminate which can be used as a data-base for fault detection.
In this present paper, an investigation has been performed to find out the combination of input p... more In this present paper, an investigation has been performed to find out the combination of input process parameters for induction hardening of AISI 1045 steel component based on desirability function. To enhance the mechanical properties of steel components using induction hardening process, quality responses like effective case depth (ECD) and hardness values are analysed for different combinations of medium frequency power, feed rate, quench pressure and temperature in a selected range. The experimental trials are conducted, based on the design matrix obtained from the rotatable central composite design (CCD), with the help of an induction hardening station equipped with a 150 kW power converter. A significant regression model is also developed to predict these quality responses using response surface methodology (RSM). To establish desirability index in a multi-response process like induction hardening, a new approach has been devised. This approach i.e. selection of both, heating and quenching parameters proved significant, which is considered as one of the major contribution of presented research work. A non destructive evaluation technique, based on dynamic response, is also developed which will further combine with optimization strategy to develop an innovative quality assurance system for industrial induction hardening process.
Journal of Mechanisms and Robotics
In this paper, an open loop compliant mechanism consisting of two elastic links actuated through ... more In this paper, an open loop compliant mechanism consisting of two elastic links actuated through piezoelectric actuators has been analyzed. The links may be joined through rigid or elastic hinge connection. The effect of piezoelectric actuators placed on an elastic beam is considered as two concentrated self-balancing moments acting on the beam at the edges of the actuator. Considering the large deflection of the two links of the mechanism under these self-balancing moments as well as end loads, the forward and inverse analyses of the mechanism are carried out. Two numerical schemes, namely, non-linear shooting (NLS) and Adomian decomposition methods (ADM) have been used for solving these problems. Numerical results are included to demonstrate the potential of the proposed methods.
Shape memory alloy (SMA) wires are capable of exerting large force and undergoing large recoverab... more Shape memory alloy (SMA) wires are capable of exerting large force and undergoing large recoverable strain. These capabilities render them suitable for being used as actuators. SMA wires are either embedded within the structure, as in a composite Choi et.al. [1], or can be placed discretely Chaudhry et.al. [2]. The advantage of discrete actuation is that, depending upon the offset provided between the structure and the wire, the actuating moment can be controlled. More the offset, higher is the actuating moment. But simultaneously the displacement requirement of the SMA wire increases with increasing offset. Depending on the nonlinear force-displacement characteristics of SMA and the flexural stiffness of the structure, there is an optimum value of the offset for which the maximum actuation of the structure can be achieved for a given input. In this paper large deflection of a cantilever beam actuated through SMA wire with varying offset has been analyzed. The results reveal the exi...
Journal of Sound and Vibration, 2015
The study proposes a set of four ARX model (autoregressive model with exogenous input) based dama... more The study proposes a set of four ARX model (autoregressive model with exogenous input) based damage sensitive features (DSFs) for structural damage detection and localization using the dynamic responses of structures, where the information regarding the input excitation may not be available. In the proposed framework, one of the output responses of a multi-degree-of-freedom system is assumed as the input and the rest are considered as the output. The features are based on ARX model coefficients, Kolmogorov-Smirnov (KS) test statistical distance, and the model residual error. At first, a mathematical formulation is provided to establish the relation between the change in ARX model coefficients and the normalized stiffness of a structure. KS test parameters are then described to show the sensitivity of statistical distance of ARX model residual error with the damage location. The efficiency of the proposed set of DSFs is evaluated by conducting numerical studies involving a shear building and a steel moment-resisting frame. To simulate the damage scenarios in these structures, stiffness degradation of different elements is considered. It is observed from this study that the proposed set of DSFs is good indicator for damage location even in the presence of damping, multiple damages, noise, and parametric uncertainties. The performance of these DSFs is compared with mode shape curvature-based approach for damage localization. An experimental study has also been conducted on a three-dimensional six-storey steel moment frame to understand the performance of these DSFs under real measurement conditions. It has been observed that the proposed set of DSFs can satisfactorily localize damage in the structure.
Smart Structures and Materials 1999: Passive Damping and Isolation, 1999
ABSTRACT Viscoelastic inserts have many useful applications in noise and vibration suppression of... more ABSTRACT Viscoelastic inserts have many useful applications in noise and vibration suppression of marine and aerospace structures. It is observed that the shape of such inserts play an important role in efficient absorption of vibration. Tapering of viscoelastic inserts may improve noise and vibration reduction in composite joints. Numerical simulations using FEM are carried out to find out the effect of the shape of inserts on vibration reduction and a combined FEM and Wave approach is developed to compare the inferences drawn from FEM analysis.
Smart Structures and Materials 1999: Passive Damping and Isolation, 1999
Active constrained layer damping has been shown to be an effective way of controlling structural ... more Active constrained layer damping has been shown to be an effective way of controlling structural vibration. The success of the technique depends significantly on the strain imparted to the constraining layer by an actuator made of a smart material -typically a piezoelectric ceramic. The possibility of using magnetostrictive smart patches as actuators is explored in this regard. Comparisons of performance are made between commonly used piezoelectric ceramic and proposed magnetostrictive actuators on the basis of maximum power consumption. It is shown that magnetostrictives offer benefits particularly in the lower frequencies.
2014 International Conference on Computational Science and Computational Intelligence, 2014
Smart Structures and Materials 1999: Passive Damping and Isolation, 1999
ABSTRACT Energy absorbing composite joints can be effective in noise and vibration suppression of... more ABSTRACT Energy absorbing composite joints can be effective in noise and vibration suppression of marine and aerospace structures. The vibration suppression in a typical Top-Hat stiffener structural joint, with viscoelastic insert is presented in this paper. Using FEM modeling, the damping performance of this composite joint is predicted. Experiments are carried out to validate the numerical analysis.
Smart Structures, Devices, and Systems IV, 2008
Fundamental research and development in smart materials and structures have shown great potential... more Fundamental research and development in smart materials and structures have shown great potential for enhancing the functionality, serviceability and increased life span of civil and mechanical infrastructure systems. Researchers from diverse disciplines have been drawn into vigorous efforts to develop smart and intelligent structures that can monitor their own conditions, detect impending failure, control damage and adapt to changing environments. Smart structures are generally created through synthesis by combining sensing, processing and actuating elements integrated with conventional structural materials. The conventional non-destructive evaluation techniques are not very effective in monitoring the structural integrity of composite structures due to their micro-mechanical complexities. With the commercial availability of the magnetostrictive (MS) material Terfenol-D in particulate form, it is now feasible to develop particulate sensors to detect damage with minimum effect on structural integrity. In present investigation, the electromagnetic response in the MS layer at the onset of delamination in one of the weakest ply of the composite laminate has been analyzed. For the numerical analysis symmetric and asymmetric carbon epoxy laminates with one of its layers embedded with Terfenol-D particles have been taken. Terfenol-D layer experiences a change in stress due to onset of delamination causing a change in its magnetic state, which can be sensed as induced open circuit voltage in the sensing coil enclosing the laminate beam. The effect of material properties, lamination schemes and placement of MS layer on the sensing capabilities has been analyzed.
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Papers by Bishakh Bhattacharya