Supapan Sangnui Chaiprapat and Somkiet Rujikietgumjorn

pp. 169 - 179

Abstract

After machining, a processed workpiece is left with irregular topographies which may affect functional applications of its surface. Particularly when the workpiece is restrained again for a consequent machining operation and the surface is selected as a locating reference, any surface deviations from its perfect geometry
will lead to inaccuracy of a machined feature. This study proposes a method to analyze effects of distributions chosen to explain irregularities of locating surfaces on feature positional tolerancing. Three types of distribution, a normal, a beta and a uniform distributions, were used in the analysis. From the simulation, it is found that the variability of the machined feature is obviously dependent on the distribution selected. Aside from mathematical complexity, this affected feature variability is another factor to be considered in choosing
an appropriate surface distribution. The method developed herein will help a designer to impose more efficient tolerancing system, reduce production cost eventually.