Papers by Author: Syh Shiuh Yeh

Abstract: Three-axis NC milling machines must carefully consider the surface interpolation algorithm and the cutting tool compensation method to achieve precise NURBS surface machining results. This study thus analyzed NURBS surface functions and developed a tool compensation method to efficiently compensate for the radius and length offsets of the cutting tool used for NURBS surface machining. A NURBS surface machining test performed on a vertical machining center further validates the proposed approaches.

Abstract: Circular ring is the most popular specimen in industry. The location of a crack in a circular ring can strongly affect the sequence of plastic hinge development which in turn affects stability of a circular ring which has been obtained theoretically in Young [1] but not any numerically. Boundary element method is employed to investigate these effects. In fact, the ring will collapse if the number of plastic hinges is up to four. The results show the potential application of the boundary element method in this project.

Abstract: Static friction generally exists in feed drive servomechanisms and usually affects the motions of CNC machine tools. In this study, the breakaway experiment is applied to measure the static friction of a feed drive servomechanism generally used in CNC machine tools, and the spectral analysis using the fast Fourier transformation algorithm is applied to analyze the frequency characteristics of the obtained static friction. Several experiments were carried out on a three-axis CNC milling machine so as to illustrate the feasibility of the developed measurement and analysis methods. The experimental results indicate that the static friction of a feed drive servomechanism is clearly position-dependent and the physical interaction of the mechanical parts in the transmission system used by the feed drive servomechanism significantly affects the characteristics of the static friction.