Blast Effects on Light Nonstructural Components

The main focus of this study was the effect of a full blast wave on lightweight nonstructural components, such as window glazing. Both the positive and negative phases of the blast pulse were considered. Previously, structural analysis models considered only the positive phase of the blast load. The structural response is defined by the peak positive and negative values of the pressure, the durations of these pressure phases, and the natural period of the structure. The parameters that govern the shape of the pulse are the distance between the blast source and the structure, and the energy dissipated in the explosion (i.e., equivalent TNT charge weight). A typical blast pressure pulse rises quite abruptly to a peak value, drops to a partial vacuum, and then returns to ambient pressure. Test data showed that, in case of failure, glazing could be either pushed into the building or pulled out of its frame. This could be possible if the relative characteristics of the full pulse, with respect to the dynamic characteristics of the structure, can excite different types of structural responses. That requires a numerical tool to show that under certain conditions the glazing can be pulled out of the structure in the direction opposite to the incoming blast.