Application of finite element analysis and Taguchi method to robust design of a micro milling machine structure

Abstract

In this paper, finite element modelling and Taguchi’s method of experimental design were combined as a tool and applied to the design of the mechanical structure of a micro milling machine. Sensitivity analysis of the machine structural configuration was conducted using a mathematical model obtained from shaping function theory which was improved by considering the squareness errors between neighbouring elements, the deflections due to the cutting forces and the thermal growth when the entire machine is subjected to a temperature rise. Then the design factors that significantly influence the accuracy of the machine tool were established. Subsequently, the shape of the main structure of the machine, which is its column, was optimised to obtain a three-legged tapered egg-bridge having very high stiffness.