Beyond Crash3: Delta V from Damage
Beyond Crash3: Delta V from Damage
by George M. Bonnett, JD
This IPTM article, Beyond Crash3: Delta V from Damage, written by George Bonnett, looks at the
future of damage analysis in traffic crash reconstruction.
According to the author, the problem with Crash3 is that it is incapable of handling curved
surfaces profiles and non-linear crush. One of the inherent basic assumptions in the Crash3
model is that all vehicles are “square,” meaning they are treated as rectangles. He also points
out that the other weakness in the Crash3 model is that it treats the resistance to deformation as
a linear function through the utilization of Hooke’s Law, which models the vehicle as a spring.
Without being able to treat the vehicle as linear, the entire model would fail. You will see why Mr.
Bonnett believes that because the resistance to damage is not linear in the real world of
deforming vehicles, the very feature that makes the Crash3 system work is one of the primary
weaknesses of the system.
The author offers a solution to the problem with Crash3 by dividing the individual elements
created by two adjacent “C” measurements into three distinct zones and weighting the individual
zones as their resistance to damage dictates. He will show you why creating these independent
zones of resistance to damage in the same direction as the depth of the damage penetration not
only enables a more accurate modeling of the resistance to damage, it removes the rectangular-
vehicle assumption in the Crash3 model.
George Bonnett is a combat proven Marine Corps aviator turned police officer turned attorney
turned crash reconstructionist turned software developer and author (REC-TEC). His whole life
has depended on minute attention to detail. In this book, he gives you the benefit of his years
of experience.
Specifications: 19 pages; 8½”x11; saddle stitched; Publisher: IPTM (August 2005)
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