Maximizing Transparency for Glazing Wall Systems subjected to Blast Loading

Abstract

Advances in blast-resistant glazing have shifted critical design demands to supporting frames, where aluminum mullions may govern façade failure under elevated blast-induced reactions. Ensuring compatibility between glazing capacity and framing performance is essential to achieve balanced, capacity-based façade design and prevent disproportionate damage. This study investigates blast load transfer at the glazing–mullion interface by quantifying demand-to-capacity ratios for aluminum mullions, steel-retrofitted aluminum mullions, and structural steel mullions across varying glazing panel sizes. Edge reactions from double- and triple-insulated glazing layups are obtained through nonlinear dynamic analyses in WINGARD, while mullion response is evaluated using single-degree-of-freedom methods. Results show that high-performance glazing, particularly triple-insulated units, improves glazing survivability but can generate reaction forces exceeding the capacity of conventional aluminum mullions. Discussions on the design, architectural, and fabrication challenges related to each mullion type is provided.  The findings highlight the necessity of coordinated glazing-to-framing design, offering practical guidance for achieving code-compliant, blast-resistant façade systems while clarifying trade-offs among compatibility, reinforcement requirements, and architectural constraints.