SBEDS-W (Single-Degree-of-Freedom Blast Effects Design Spreadsheets for Windows) is an Excel-based tool for design of window components subjected to airblast using single-degree-of-freedom (SDOF) methodology. SBEDS-W enables the user to choose different glazing types or framing components with readily available parameters related to material properties, geometry, and failure probability models for glazing. Users can also choose prescribed mullion shapes or directly enter user-defined properties for geometry, accounting for thermal breaks as required.
The Glass Failure Prediction Model by Beason and Morgan and glass deflection to load relationships characterized by Dalgliesh are used to develop resistance-deflection curves for glazing up to failure. Theoretical membrane equations modified with empirical factors to match blast test data are used to calculate response of laminated windows and windows with attached film and. A two-degree-of-freedom approach is used to model insulated glass units (IGUs). The response of window framing components, including the effects of thermal breaks and steel or aluminum inserts, is calculated using SDOF-based analysis. SBEDS-W calculates the window damage level, or hazard level for failed windows, and the corresponding Level of Protection (LOP) that the window provides. The damage level and LOP are also calculated for window framing components. The SBEDS-W methodology is outlined in the U.S. Army Corps of Engineers (USACE) Protective Design Center Technical Report (PDC-TR 12-01), “Methodology Manual for the SBEDS-W Window Analysis Spreadsheet”.
SBEDS-W has been developed by Protection Engineering Consultants senior principal Chuck Oswald and is distributed by the USACE.