Papers by Keyword: Diffuse Approximation

Abstract: Tool wear can affect surface quality of the work-piece and frequent tool changing leads to low machining efficiency. Tool life of milling ultrahigh strength steel is thus an important indicator in manufacturing. In this study, we compare Diffuse Approximation (DA) and Kriging method for predicting tool life of milling ultrahigh strength steel. Latin hypercube method is employed as design of experiments after comparing three different designs of experiments (full factorial design, Latin Hypercube Sampling (LHS) and random design). An example with LHS is taken to investigate accuracy of approximation of DA and Kriging method. The results show that the DA provides significant improvement in accuracy of prediction compared with Kriging method. Tool life of milling ultrahigh strength steel predicted by DA is almost close to ‘exact’ values, especial for big mutation of adjacent measured values. The most errors with DA are less than ones with Kriging method.

Abstract: The selection of adaptable machining parameters is a key part in numerical control (NC) milling process. Deterministic optimal parameters are obtained without considering the uncertainties of machine tools. So a reliable optimization method was introduced in this study. We focus on a response surface methodology (RSM) adapted to reliability-based design optimization (RBDO) based on Diffuse Approximation (DA). A variant of the first order reliability method (FORM) is chosen to calculate the safety index. Case study is investigated for the NC milling operations of ultrahigh strength steel. We show how to get the optimal parameters with the safety index by the reliable optimization method.