Intelligent design of cutting tools using smart material
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Intelligent design of cutting tools using smart material Maki K. Rashid Æ Khalil Ibrahim Shihab
Received: 3 February 2006 / Accepted: 13 September 2006 / Published online: 7 November 2006 Ó Springer Science + Business Media B.V. 2006
Abstract Shaving metal from a workpiece to produce desired geometric shape is carried out in turning machine tool. Attenuating a micro level vibration of a cutting tool using smart materials can save old machines and enhance flexibility in designing new generations of machine tools. The finite element method is employed to investigate structural stiffness, damping, and switching methodology using smart material in tool error attenuation. In this work, a dynamic force model is deployed to investigate the effectiveness of using such technique in toolpost dynamic control. Effects of short and open circuit conditions on tool critical frequencies for different structural stiffness ratios are assessed. In the transient solution for tool tip displacement, the pulse width modulation (PWM) technique is implemented for smart material activation to compensate for the radial disturbing cutting forces. A Fuzzy Algorithm is developed to control actuator voltage
M. K. Rashid (&) Mechanical and Industrial Engineering, Sultan Qaboos University, P.O. Box 33, 123 Al-Khod, Muscat, Sultanate of Oman e-mail: [email protected] K. I. Shihab Department of Computer Science, College of Science, Sultan Qaboos University, P.O. Box 36, Al-Khoudh, Muscat 123, Sultanate of Oman e-mail: [email protected]
level enhancing improved dynamic performance. The influence of minimum number of PWM cycles in each disturbing force cycle is investigated in controlling the tool error growth. A methodology is developed to utilize toolpost static force–displacement diagram to obtain required activation voltage to shrink error under different dynamic operating conditions. Time delay of applied voltage during error attenuation is evaluated at different frequencies. Keywords Tool design Smart material Dynamic systems Mechatronic design Intelligent manufacturing Machining error
1 Introduction Raw material conversion to new product requires material removal processes using machine tool. Demand for higher productivity in automated manufacturing brought attention for controlling machine tool dynamics for better machining accuracy. Both economical and ecological factors encouraged old conventional machines to continue in service by overcoming tool vibration problems. Various factors might affect machining process (Lin and Weng 1991), some of them are non-measurable and others might change in realtime. However, the wider use and the availability of cost effective microcontrollers encouraged the
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implementation of intelligent control schemes to overcome such time dependent problems. The tiny unfavorable relative motion between the cutting tool and the working piece that associated with high excitation forces encouraged the use of smart material actuators to counteract such motion errors (Dold 1996). Rigid fixture is a goo
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