MODELING AND SIMULATION OF INTELLIGENT CUTTING TOOLS

摘要

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, 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 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.