VEXDAM 5.2 represents the fifth version of the vapor cloud explosion counterpart to the High Explosive Damage Assessment Model (HEXDAM), now with the VEXDAM Man concept. Like HEXDAM this software has been designed to allow the rapid evaluation of damage experienced by each structure within a facility as a result of a primary explosion, and any accompanying secondary explosions produced by vapor clouds at any elevation. Its primary application is safety analysis of petrochemical fuel storage and refining/manufacturing facilities. A number of technical papers have been published dealing with our work in this area. The code can also be used to evaluate terrorism and sabotage threats to a facility.  A demonstration of this software is available.

The program has the capability to model an unlimited number of structures, each with different dimensions and structural properties, including elevated structures. The Parametric Analysis of Single Structure (PASS) capability allows the user to determine the influence of various important independent variables on damage, overpressure, and impulse experienced by an individual structure within a facility.

VEXDAM 5.2 utilizes recently developed dimensionless curves of overpressure and pulse duration versus range, based on the multi-energy method, to predict overpressure and impulse at each structure/person location. Structure shielding, based on the three-doublet advanced shielding algorithm, and secondary explosion effects are calculated, and damage/injury levels are determined for each structure. VEXDAM 5.2 produces output in the form of damage/injury tables, before-blast and after-blast displays, overpressure, impulse, and damage/injury contour plots, and damage/injury-versus-distance graphs, all in color. Advanced graphics features include three-dimensional graphics in the form of oblique projections, as well as two-dimensional horizontal and vertical cross sections for overpressure, impulse, and damage/injury contour plots.

To ensure the software is usable by installation engineering, planning, and safety offices, the hardware requirements for VEXDAM 5.2 have been kept at a modest level. An IBM PC or compatible with a color monitor, a dot matrix printer, and a color plotter (for hardcopy of screen graphics) is sufficient to execute VEXDAM 5.2.

Recently, we entered into a working agreement with Trinity Consultants, leading to the development of more advanced versions of our explosive safety software.

CAPABILITIES

• Capability to model elevated vapor clouds.
• Blasts produced by as many as ten subclouds within primary vapor cloud.
• Compatibility with Vulnerability Assessment of Structurally Damaging Impulses and Pressures (VASDIP) software.
• Damage prediction for 104 basic structure types, plus any user-defined structure types.
• Damage prediction for overpressure-sensitive and dynamic pressure-sensitive structures.
• Injury prediction for 28 body components comprising the human body.
• Use of the three-doublet advanced algorithm to predict shielding effects by each structure on other structures.
• Prediction of blast damage resulting from secondary vapor cloud explosions triggered by the primary vapor cloud blast.
• Capacity to model an unlimited number of individual structures/persons within a facility.
• Capability to model elevated structures.
• Automatic or user-specified structure subdivision.
• Generation of overpressure, impulse, and damage contours (3-D oblique projections, plus 2-D horizontal and vertical cross sections).
• Zoom feature for all graphical displays.
• Parametric Analysis of Single Structure (PASS)

• IBM PC or compatible
• Hard disk drive
• Dot matrix printer (with graphics)
• Color plotter
• Color monitor and graphics card
• DOS 3.2 or later or Windows 95
• 640K RAM
• Math co-processor recommended

• Ambient conditions
• Primary explosion
• identity of fuel
• number and location of subclouds
• mass of fuel in each subcloud
• explosive strength of each subcloud
• Individual structures
• location
• dimensions (length, width, height)
• orientation
• structure/person type
• 104 basic inanimate types
• 19 human body component types
• explosive threshold for secondary explosions
• Secondary explosion characteristics
• identity of fuel
• mass of fuel
• explosive strength

• Before-Blast Display - Provides 3-D oblique projection in color of all structures/persons being modeled

 

 
 
 
 
 
 
 
 
 
 
 
 
 

• Damage Table - For each structure/persons provides overpressure, impulse, and damage/injury levels.

 

 
 
 
 
 
 
 
 
 
 
 
 
 

• After-Blast Display - Provides same 3-D oblique projection in color as Before-Blast but also indicates damage/injury level to each structure/persons.

 

 
 
 
 
 
 
 
 
 
 
 
 
 

• Damage/Injury vs Distance Graphs - Provides color-coded plot of damage/injury levels to all structures/persons versus distance from primary explosion.

 

 
 
 
 
 
 
 
 
 
 
 
 
 

• Pressure Contours - Provides 3-D oblique projection and 2-D horizontal and vertical cross sections of overpressure and impulse contours of entire layout in color.

 

 
 
 
 
 
 
 
 
 
 
 
 
 

• Damage/Injury Contours - Provides 3-D oblique projection and 2-D horizontal and vertical cross sections of contour plots of damage levels to any structure/persons in color.

 

 
 
 
 
 
 
 
 
 
 
 
 
 

• Parametric Analysis - Provides plots of variation of overpressure, impulse, and damage to a single structure as a function of the explosion characteristics and the location of the vapor cloud.

• Petrochemical Storage Siting
• Petrochemical Refining/Manufacturing Design
• Terrorist and Sabotage Threat Analysis

• Structural elements (7 different types)
1. aluminum
2. asbestos
3. brick
4. concrete
5. glass
6. steel
7. wood
• Composite structures (97 different types)
• bridges
• buildings
• commercial/administrative
• industrial
• residential
• hangars
• magazines
• shelters
• underground structures
• transportation equipment
• aircraft
• railroad
• earth-moving
• naval vessels
• vehicles
• communications/electrical equipment
• industrial equipment
• gas and oil storage tanks
• User-defined structures
• compatible with VASDIP
• unlimited number of choices

• Soft Tissue (4 types)
• Eardrums
• Larynx
• Lungs
• G.I. System
• Bones (15 types)
• Skull
• Cervical Vertebrae
• Clavicle
• Ribs
• Thoracic Vertebrae
• Pelvis
• Lumbar Vertebrae
• Humerus
• Radius
• Ulna
• Metacarpals
• Femur
• Fibula
• Tibia
• Metatarsals