Facility Vulnerability with VISAC

Setup Standard Grids

Once the geometry and logic models have been finalized, grids of Quick Blast calculations can be made. A grid is simply a set of blast points filling a 3D rectangle. At each point a Quick Blast calculation is done and the results for all points are stored together. These points can then be searched by outcome. Users can define the extent of the grid rectangle in all three dimensions, the spacing of the grid points, the size and type of explosive and the method of ray tracing for the Quick Blast calculation.

For a given facility, grids can be created automatically by VISAC. This is done using the menu option Facility/Grids/Setup Standard Grids. (Note: this will erase any existing grids for the facility.) This option does not calculate the blast damage at each grid point, it only determines the grid parameters. Standard grids made by VISAC include:

a Mark 82 general purpose bomb, for interior points
a Mark 84 general purpose bomb, for interior points
a small (800 lbs TNT) truckbomb, for exterior points
a large (3000 lbs TNT) truckbomb, for exterior points

VISAC tries to determine the extent of each of these grids by using the outer walls of the buildings. Buildings close together will be grouped into the same grid so that points are not overlapped. Once the standard grids are created by VISAC, they are still able to be fine-tuned by the user.

The user does have to have VISAC create the standard grids. The user may define his own grids (or none at all). To define your own grids, launch the Contour viewer using the VISAC menu option Facility/Grids/Edit Grid Parameters. In the Grid Select box, the user can click on the "add" button to start defining a new grid. The points can be calculated with each grid definition or calculation can be put off until all the grids are defined.

Oak Ridge National Laboratory, 2004

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