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Abhijit Ganguli

Bio: Abhijit Ganguli is an academic researcher from Indian Institutes of Technology. The author has contributed to research in topics: Rebar & Nondestructive testing. The author has an hindex of 9, co-authored 27 publications receiving 383 citations. Previous affiliations of Abhijit Ganguli include Université libre de Bruxelles & Indian Institute of Technology Bombay.

Papers
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Journal ArticleDOI
TL;DR: In this paper, the effect of active damping on regenerative chatter instability for a turning operation was investigated and two approaches are used for this purpose: the traditional stability analysis technique in Altintas [Manufacturing Automation, Cambridge University Press, Cambridge, 2000] and other works is adopted and a correlation between the chip shape (which is dependent on the spindle speed) and system damping is presented.

96 citations

Journal ArticleDOI
01 Aug 2005
TL;DR: In this paper, a numerical stability analysis is performed using the root locus method and it is shown that, along with the structural poles, eigenvalues due to the delay parameter may contribute to instability.
Abstract: The motivation of the work is twofold: (a) understand the physics behind regenerative chatter and the influence of structural damping and (b) demonstrate an active damping technique based on collocated actuator/sensor pairs. A numerical stability analysis is performed using the root locus method and it is shown that, along with the structural poles, eigenvalues due to the delay parameter may contribute to instability. Since experimental demonstration of chatter in real machines is difficult, an alternative way of demonstration via a mechatronic simulator is presented, using the ‘hardware-in-the-loop’ concept. The mathematical model of the regenerative cutting process in turning is simulated in a computer and this is interfaced to a beam, representing the structural dynamics of the machine, via a displacement sensor and force actuator. In this way, a hardware and a software loop are combined. In a second step, an additional control loop is added, consisting of an accelerometer sensor and a collocat...

62 citations

Journal ArticleDOI
TL;DR: The proposed technique has some advantage since knowledge about the undamaged scenario for the concrete medium is not necessary to assess its integrity, and is capable of creating clear images of the inspected region of interest.

58 citations

Journal ArticleDOI
TL;DR: In this paper, a stiffened plate finite element with piezoelectric effects is formulated and a velocity feedback algorithm is employed in the active vibration control of the stiffener.

43 citations

24 Nov 2005
TL;DR: In this article, the authors proposed active damping as a potential control strategy for chatter instability in machine tools and found that the minimum value of the stability limit is proportional to the structural damping ratio for turning operations.
Abstract: The aim of the thesis is to propose active damping as a potential control strategy for chatter instability in machine tools.The regenerative process theory explains chatter as a closed loop interaction between the structural dynamics and the cutting process. This is considered to be the most dominant reason behind machine tool chatter although other instability causing mechanisms exist.The stability lobe diagram provides a quantitative idea of the limits of stable machining in terms of two physical parameters: the width of contact between tool and the workpiece, called the width of cut and the speed of rotation of the spindle. It is found that the minimum value of the stability limit is proportional to the structural damping ratio for turning operations. This important finding provides the motivation of influencing the structural dynamics by active damping to enhance stability limits of a machining operation.A direct implementation of active damping in an industrial environment may be difficult. So an intermediate step of testing the strategy in a laboratory setup, without conducting real cutting is proposed. Two mechatronic "Hardware in the Loop" simulators for chatter in turning and milling are presented, which simulate regenerative chatter experimentally without conducting real cutting tests. A simple cantilever beam, representing the MDOF dynamics ofthe machine tool structure constitutes the basic hardware part and the cutting process is simulated in real time on a DSP board. The values of the cutting parameters such as spindle speed and the axial width of cut can be changed on the DSP board and the closed loop interaction between the structure and the cutting process can be led to instability.The demonstrators are then used as test beds to investigate the efficiency of active damping, as a potential chatter stabilization strategy. Active damping is easy to implement, robust and does not require a very detailed model of the structure for proper functioning, provided a collocated sensor and actuator configuration is followed. The idea of active damping is currently being implemented in the industry in various metal cutting machines as part of the European Union funded SMARTOOL project (www.smartool.org), intended to propose smart chatter control technologies in machining operations.

29 citations


Cited by
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Journal ArticleDOI
B.B. Bauer1
01 Apr 1963

897 citations

Journal ArticleDOI
TL;DR: A review of the state of research on the chatter problem and classifications the existing methods developed to ensure stable cutting into those that use the lobbing effect, out-of-process or in-process, and those that, passively or actively, modify the system behavior as mentioned in this paper.
Abstract: Chatter is a self-excited vibration that can occur during machining operations and become a common limitation to productivity and part quality. For this reason, it has been a topic of industrial and academic interest in the manufacturing sector for many years. A great deal of research has been carried out since the late 1950s to solve the chatter problem. Researchers have studied how to detect, identify, avoid, prevent, reduce, control, or suppress chatter. This paper reviews the state of research on the chatter problem and classifies the existing methods developed to ensure stable cutting into those that use the lobbing effect, out-of-process or in-process, and those that, passively or actively, modify the system behaviour.

790 citations

Journal ArticleDOI
TL;DR: A critical review of the different chatter suppression techniques can be found in this paper, where the evolution of each technique is described remarking the most important milestones in research and the corresponding industrial application.

454 citations

Journal ArticleDOI
TL;DR: In this article, some of the chatter stability prediction, chatter detection and chatter control techniques for the turning process are reviewed to summarize the status of current research in this field and to identify a research scope in this area.
Abstract: Chatter vibrations are present in almost all cutting operations and they are major obstacles in achieving desired productivity. Regenerative chatter is the most detrimental to any process as it creates excessive vibration between the tool and the workpiece, resulting in a poor surface finish, high-pitch noise and accelerated tool wear which in turn reduces machine tool life, reliability and safety of the machining operation. There are various techniques proposed by several researchers to predict and detect chatter where the objective is to avoid chatter occurrence in the cutting process in order to obtain better surface finish of the product, higher productivity and tool life. In this paper, some of the chatter stability prediction, chatter detection and chatter control techniques for the turning process are reviewed to summarize the status of current research in this field. The objective of this review work is to compare different chatter stability prediction, chatter detection and chatter control techniques to find out most suitable technique/s and to identify a research scope in this area. One scope of research has been identified as establishing a theoretical relationship between chatter vibration and tool wear in order to predict tool wear and tool life in the presence of chatter vibration.

359 citations

Journal ArticleDOI
TL;DR: In this article, a new analytical solution to this problem is presented, and demonstrates its performance using time domain milling simulations, and a 40-50% improvement in the critical limiting depth of cut is observed, compared to the classically tuned vibration absorber.

192 citations