When will msmac3D add Occupant/Rider/Pedestrian Simulation?

Subjects related to the reconstruction and simulation of Occupants in vehicles and Pedestrians struck by vehicles, ATB & ATB clones #ATB #MADYMO #MultiBody
MSI
Site Admin
Posts: 2302
Joined: Thu Jun 18, 2009 12:37 pm

When will msmac3D add Occupant/Rider/Pedestrian Simulation?

Post by MSI »

Q: I analyze collisions involving motorcycles. I've already done some reconstructions using pc-crash software.
In the Msoft3D the bike does not fall, since it seems to only work in 2D.
Another necessary modeling is for motorcyclists and companions on the bikes to be modeled separately (dummies) in order to reconstruct their flight by moving from the bike in the collision.
Can you make a prediction if in the near future msoft3D can meet this demand?


A: Msmac3D can simulate motorcycle crashes in 3D. We’ve begun testing. Main item is to set the vehicle suspension type to 1 and use nodes. An instructional video on that which should be posted soon.

As far as occupant/rider simulation, Be very careful with pc-crash.
One of the first problems is that they are using the ATB program for their ‘multi-body’ simulations however NEVER mention or reference it.
Why?
I suspect they want to distance themselves from the ATB because it IS a good research tool BUT should not be used in individual crash reconstruction
I and others have written why Main point is no two humans are the same, and small changes in a motorcycle rider height and position at impact, interaction with the striking or struck vehicle and variations in tumbling/sliding/rolling to rest can make major changes in the trajectory of the rider post impact.
Also pc-crash is limited by the assumption of instantaneous momentum exchange during collision interactions so it requires a judicious choice of point and angle for the instantaneous exchange that can make for different bike/rider/passenger responses.
Also the ATB/multi-body simulation can simulate collision interactions over time however limited to single point hyper-ellipsoid contact points.
It is an interesting approach just be sure to realize that your results may vary dramatically depending on your judicious choices.

We have and are very familiar with occupant simulation (we've had the pleasure of working with the late Dr. John Fleck for decades on many projects) we currently don’t have plans to market it since as we include in our references on occupant/rider/pedestrian simulations:
  • Occupant/Rider/Pedestrian simulations should be used in forensics and crash reconstruction only as a tool to assist in understanding gross occupant/Rider/Pedestrian kinematics. Any results or conclusions drawn from an application related to detailed occupant/rider/Pedestrian kinematics involve so many approximations, estimates, and assumptions that they must be recognized as not being compatible with sound engineering practices and principles and, therefore, not scientifically supportable.