Offset Motorcycle collision ACM issues?

[MSI]

From another forum:
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.

Others responding to your question provided a reference on offset DeltaV,
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?

We also have a related topic on 'MC speed to rotate a vehicle'

• 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

This topic reminds me need to activate the 'change mass during a collision' option we created

• modeling an engine separating from a vehicle during a crash
  from way back in the day 1997

Coincidentally 1997, a busy year as we published 4 SAE papers all of which made SAE transactions

What a long strange trip it's been...

Let us know if any additional questions/clarifications, etc.