Q: I was reaching out to see if any information to explain energy that is lost/unreported on an ACM report? More specifically a motorcycle strike the right rear quarter panel of a vehicle. The impact rotated the vehicle more than 100 degrees. No pre-impact braking and it was not a direct 90 degree hit. The ACM report is under reporting the delta-v which is not accounting for all of the motorcycles speed.
A: Some further clarification:
- What type of collision?
- Did rider(s) remain on bike/interact with car or fly over it/partially interact with it?
Since the possibility of a changing mass during the collision will affect the DeltaV/acceleration ACM measurements/calculations, etc.
- Did rider(s) remain on bike/interact with car or fly over it/partially interact with it?
Please also see our paper:
- 1997 SAE "RICSAC-97 - A Reevaluation of the Reference Set of Full Scale Crash Tests"
And our forum topic related to that: DeltaV/Accel at location other than CG?
- A first pass crude evaluation of what speed is required for a motorcycle to rotate a vehicle 180 degrees. It demonstrates that using a time forward simulation (which calculates the forces and moments for every millisecond during a collision) provides a way to evaluate motorcycle collisions at an offset:
Motorcycle Crash Which Spun the Vehicle 180 Degrees
- modeling an engine separating from a vehicle during a crash
from way back in the day 1997
What a long strange trip it's been...
Let us know if any additional questions/clarifications, etc.