The PEC technical presentation entitled Coupled High-Strength Window and Mullion Model Validation was presented at the GlassCon Global Conference in Philadelphia.
Glazing in storefront and curtainwall configurations are increasingly used in areas subjected to blast load. Current design approaches typically use single degree of freedom (SDOF) methods to analyze the performance of both the window glazing and mullions. The flexural resistance and mass of each component must be identified to solve the SDOF representation. Then, the resistance curve is calculated based on span, support conditions, cross sectional stiffness, assumed deformed shape, and a failure criterion. This paper addresses the latter two critical parameters.
Dynamic verification of deformed shape is difficult to assess through testing and has historically been calculated through analytical and numerical methods. However, new measurement methods provide high resolution, high speed deformation measurements through the use of Digital Image Correlation, which is a stereoscopic camera setup capable of measuring three dimensional deflections of both the window glazing and mullions simultaneously. This allows analysis of deformed shape and the interaction between the glazing and mullions. The failure point for the resistance curve was determined by modifying the Glass Failure Prediction Model (basis for ASTM E1300) to handle high-strength glass. Together these models were used to validate SDOF and finite element models used in industry for storefronts comprised of highstrength glass.
Read the full TechNote entitled Coupled High-Strength Window and Mullion Model Validation.