Accession Number : ADA603332


Title :   Manufacturing Science of Improved Molded Optics


Descriptive Note : Final rept. 1 Oct 2009-3 Sep 2013


Corporate Author : CLEMSON UNIV SC OFFICE OF SPONSORED PROGRAM


Personal Author(s) : Joseph, Paul F ; Richardson, Kathleen C ; Luzinov, Igor ; Blouin, Vincent


Full Text : http://www.dtic.mil/dtic/tr/fulltext/u2/a603332.pdf


Report Date : 05 Dec 2013


Pagination or Media Count : 139


Abstract : Computational mechanics and glass science have been applied to the study of precision glass molding (PGM). Early in the study a coupled thermo-mechanical finite element model was rigorously validated and then used in a detailed sensitivity analysis to identify important material and process behaviors. This experience led to a detailed investigation to characterize friction and determine viscosity in the important range of 107.5 109 Pa*s. Viscosity is the primary behavior that allows shape change in glass forming processes and as such must be characterized very accurately. Furthermore, in the viscosity range of interest friction complicates approaches used to obtain viscosity such as parallel plate viscometry. In addition stress relaxation was identified as a very difficult behavior to characterize and a special no-slip glass specimen was designed to obtain it. The most important behavior revealed in the sensitivity analysis was structural relaxation, the characterization of which was a focus in the last year of the project. In addition extensive work was done developing analytical processes to evaluate mold tooling-glass material interaction tendencies in PGM. This provides the know-how needed in both research and development to successfully refine the PGM process through both computational mechanics and glass science.


Descriptors :   *FRICTION , *GLASS , *LENSES , *MOLDING TECHNIQUES , *STRESS RELAXATION , *VISCOSITY , CARBON , COATINGS , MANUFACTURING , SENSITIVITY


Subject Categories : Ceramics, Refractories and Glass
      Mfg & Industrial Eng & Control of Product Sys
      Fluid Mechanics
      Optics
      Mechanics


Distribution Statement : APPROVED FOR PUBLIC RELEASE