Pc-Crash MultiBody issues

Subjects related to the reconstruction and simulation of Occupants in vehicles and Pedestrians struck by vehicles, ATB & ATB clones #ATB #MADYMO #MultiBody
Post Reply
MSI
Site Admin
Posts: 2007
Joined: Thu Jun 18, 2009 12:37 pm

Pc-Crash MultiBody issues

Post by MSI »

Had a case a few years back where an "expert" improperly used the Pc-Crash MultiBody option to try to justify/validate their incorrect opinion that the speed of a car was slow when striking a pedestrian.
  • They simulated a MultiBody pedestrian being struck by a vehicle and their criteria for vehicle speed was that if the simulated pedestrian hit the windshield, the speed was too high?!!
    • Obviously issues missing in this simplisitic erroneous foolishness:
      • the lack of active muscles in the simulation,
      • the lack of any pre-impact reaction in the pedestrian
        • This pedestrian saw the vehicle coming and reacted...was it a jump?
        • There was leg interaction/injury with the front bumper/articulation (points of evidence) NOT included in the simulation or tested
          • How might the leg interaction on front bumper affect how far up the hood a pedestrian might travel at various speeds/reactions/etc in reality vs in the simulation??!!
      • the assumptions of values of stiffness and friction used for the pedestrian interaction with the hood,
        • clothing vs hand/skin friction/forces/etc
      • and many other factors,
    • affect how 'far up the hood' a pedestrian will travel.
    • Also of important note: In the subject case the pedestrian grabbed onto the vehicle (so hand grabbing? vs clothing sliding?) and stabilized to ride on the hood until brakes were applied by the driver.
      (more on this case perhaps at a later time)
We created a video of WHAT HAPPENS when you simply allow the multibody model to fall...
(a friend later added the music...)

be sure to also see
Quick LINKS: ->HOT TOPICS<- ->msmac3D LEASE pricing!<- ->McHenryForum Index<-
Question? Comment? Please email forum@mchenrysoftware.com
(c)McHenry Software ALL Rights Reserved.
Post Reply