Abstract: The paper presents a feasible study of modeling on tool life for the failure modes of tool wear and fracture based on methods of catastrophe theory. By means of least square regression, the fusion model of tool wear/fracture in turning/endmilling using 3-degree polynome with veriable coefficients has been established. Using the model, a monitoring system of the, turning and end-milling processes is completed. The results of experiment have shown that the rate of success of monitoring tool wear and fracture is more than 95%, and the predicting error value of tool wear is less than 10%.

Key words: Catastrophe -theory, Modeling, Monitoring system, Prediction, Tool life