Panel Blast Analysis
Overall, for typical UFC explosive weights I and II with conventional standoff distances, the SlenderWall system performs well. The analysis included herein show that the SlenderWall performs well for a representative blast load application. A summary table of the component response is seen below.
|Precast Panel||0.10 degrees||1.83||4,471 lb|
The total end reaction at the connections to the structure is approximately 15,000 lb.
Nelson stud spacing shall be determined on a case-by-case basis, depending on the blast requirement, final panel configurations and light gauge stud spacing for the project under consideration. Localized punching shear at the Nelson studs must be analyzed to ensure the panels satisfy both the initial blast as well any rebound requirement, if applicable.
For the case study noted in this report, the Nelson stud anchor spacing would need to be less than the standard 24 inches o.c. If the designers wish to maintain the standard 24-inch Nelson stud spacing, another option would be to insert 1 ¼ inch square plastic shims at each Nelson stud to reduce the effects of localized punching shear. The designer should evaluate each project separately to determine which of these options is the most economical option.
This report presented a simplified analysis of a given panel geometry using simplified models for the purpose of estimating global response and identifying potential failure modes. Future studies could be performed using Finite Element Analysis or explosive testing to determine system responses that simplified methods would be less likely to predict. However, it should be noted that the methods used in this report are the same methods commonly utilized on façade design for both precast and curtain wall systems.
As is true with any blast-rated building, the Design Team must evaluate each project on a caseby- case basis. Factors such as stand-off, building configuration and panel geometry may all need to be factored in to the blast response evaluation.
Under the blast conditions analyzed in this report, the Slenderwall panels performed remarkably well. The global response of the system indicates that the Slenderwall panel system is an extremely viable option when a moderate level blast design of the façade is required. The results of the analysis demonstrate the global response of the system, which confirm that the overall system performs satisfactorily and may be used in blast applications.