Date of Award
Master of Science
Industrial and Manufacturing Engineering
Dr. Philip J. Guichelaar
Dr. David M. Lyth
Dr. Abdolazim Houshyar
Masters Thesis-Open Access
When coordinate measuring machines are used to measure the complex shapes of foam patterns, the spherical probe tips indent into the soft surface of the pattern. Such indentation represents a measurement error since the indicated dimension will not be the same as the actual dimension. To determine the magnitude of error, the depth of probe tip indentation into PMMA and EPS foam surface (i.e., elastic indentation) was measured as a function of time, applied load, and foam density. The residual indentation after the removal of the load (i.e., plastic indentation) was also studied.
The depth of elastic indentation increased with an increase in density for EPS patterns and decreased for PMMA patterns. The depth of plastic indentation decreased with an increase in density both for EPS and PMMA patterns. Elastic indentation increased with time whereas plastic indentation decreased with time. Furthermore, molding conditions significantly affect the pattern properties and thus the depth of indentations.
Nenawati, Sanjay, "The Indentation of Foam Pattern Surfaces by Coordinate Measuring Machine Probes" (1992). Master's Theses. 854.