- In some recent investigations and articles some issues have occurred due to a 50g (or other) limit in some EDRs.
As an example, from the 2021 NAPARS Crash test2 of a head-on collision between a 6973 lb 2003 GMV Savana Van at 34 MPH into a 2946 lb 1999 Pontiac Grand Am at 68 MPH.
The EDR traces for the Grand Am definitely showed the limit in the traces which affects the Impact Speed Change/DeltaV calulations.And the DeltaV for the Savana Van was lost (EDR issues)so how to resolve?
(and note they also had 1300 lbs of sand in the van to see the effects of a 'secondary impact' as the sand bags ruptured etc, more on that later)
Running the crash with msmac3D produced the following results:The option we added was for the post processing calculations of DeltaV at CG and/or any locations on the vehicle
we NOW have added the ability to limit the maximum acceleration used in the DeltaV caluclation.
When you run smacthp it now has an option limit:And running for with and without a 50 G limit you see the difference:And the following are the msmac3D acceleration time histories with and without the limit
- and note, the limit is ONLY for post processing purposes since although the EDR is limited, the vehicle is THE SAME!!
More to come, stay tuned!