The optimization of drilling conditions by using accelerated life model

In this paper, we have constructed the parametric accelerated failure time model for the reliability of a drilling tool basing on the results of drill reliability experiment. The second-order polynomial model was considered as the covariate function, and the baseline reliability function was taken from the family of Weibull distributions. The goodness-of-fit of the model was tested with the Kolmogorov, Cramer-von Mises-Smirnov and Anderson-Darling type tests by the sample of residuals. Using the constructed model, we have found the optimal cutting conditions (the feed rate and the rotational speed), which minimize the economical costs. Moreover, the failure-free operation times have been calculated for various probabilities under obtained optimal cutting conditions.