Scope of Research
The scope of this research was to determine the durability of the primary weather seal of an insulating-glazing unit under cold-bending deformation. The research team hypothesized that the primary cause of IGU failure (moisture
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Rochester Institute Of Technology pursuant to License Agreement. No further reproductions authorized.
infiltration) would be caused by a strain in the edge seal. The standard test for determining durability is specified in American Society of Testing and Materials (ASTM) E2188-10  and E2190-10  and these standards specify an IGU of a certain size and make-up. Because of scaling problems, these standard IGUs cannot be deformed in the same way as a full-scale curtain-wall panel to obtain the same edge-seal strains. Therefore, the team devised a test procedure that had the following steps: (1) model a full-sized curtain-wall panel with Finite Element software, (2) perform a full-scale test on a curtain-wall panel for model verification, (3) deform the edge seal of a small IGU specimen equal to the deformation in the finite-element model and full-scale test, and (4) perform ASTM durability testing on the small specimen to determine the relative performance of a cold-bent IGU as compared to a “flat" IGU.
This testing and evaluation was all done within the scope of inch pound units. SI units are provided in parenthesis throughout this document.