McHenry Forum - Crash Reconstruction & Simulation

New: Use this link to go to the latest post on this thread Some Simplified Momentum Misconceptions: And please note this is not to dismiss simplified momentum analysis, it is to help all who use it to understand the assumptions, to encourage that they test a range of assumed input numbers to reveal...

Some comments on Momentum analysis: (1) The collision between two vehicles is not the same as a collision between two pool balls. More like two crushable rectangular boxes on wheels. And vehicles are not 'balls' or 'points', they are finite dimensioned crushable objects which may behave quite differ...

CASR Speed Study In 1994 & 1998 McHenry Software participated in a study of crashes with the Road Accident Research Unit (RARU) of the University of Adelaide, Australia. They now go by the name Centre for Automotive Safety research (CASR) Summary The Road Accident Research Unit at Adelaide Univ...

For historical information, check out " Roadside Design for Safety " by Stonex (1960). It may be in other Stonex papers (some published through SAE since they include a lot of history on crash safety research). In the 1960 paper he towed vehicles sideways through wet and dry sod. In the St...

Q: Assuming that a t-boned vehicle created a rim gouge from the impact, how far (laterally) would you expect the vehicle to have traveled prior to commencing the gouge? A: Some things to consider in relation to the location of a gouge mark to the initial point or area of impact: 1) Impact/separation...

Q: Does CRASH/EDCRASH include restitution? A: NO! Restitution is not included in the fundamental equations of CRASH. Restitution is NOT included in any commercial version of CRASH. Restitution consists of two separate aspects: A partial dimensional recovery and A partial restoration of kinetic ener...

The fundamental principle used by photogrammetry is that through "known" distances into and across a photograph, you can traingulate to determine "unknown" distances in a photograph. Check out Northwestern and look for 'Perspective Grid for Photographic Mapping of Evidence' it to...

Q: I am used to discussing Delta -V for the forces on a person in a crash. Another expert is using G's. What is the conversion from one to the other? A: DeltaV, or Impact speed change, is normally associated with a collision. (to avoid those among you who will say `but you encounter a DeltaV when br...

The term " Ball Bank Indicator " refers to an inclinometer that is used for the specific purpose of determining safe (uniform advisory) curve speeds for horizontal curves. It measures the overturning force (side friction), measured in degrees, on a vehicle negotiating a horizontal curve - ...

Welcome to the new McHenry Software forum! June 22, 2009 : This forum is being added to provide an active interaction between McHenry Software , our users and the Collision Reconstruction community. We will post up software questions and answers, information, tips, specific instructions, and a wide...