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How to define BUSHING element in Adams correctly?

Hello, colleagues.
 
I have a question about proper bushing definition in Adams (especially in Car). Probably this issue have already solved many times, but it is still essential for modelling.
 
The question is: what is the right way to define active and reactive bodies in bushing? Some say that one should use the mechanism (say, vehicle suspension) topology and follow through it from part that give an excitation (a wheel, for example) to parts which react on this excitation. Also, there is an idea to consider I/J parts for bushing as inner/outer rings.
 
There is an issue when it comes to bushings with different radial stiffness. When you model such a bushing with different I/J parts order, you receive different results of bushing reaction. This difference may lead to different behaviour of related elements. I suppose it's related with bushing formulation described in the KB8013987 tech article.
 
For instance, there is a toelink, which has a bushing with different radial stiffnesses and a spherical joint. In this case different I/J parts order lead to different rotation of toelink around its axis and to different values of spherical joint working angle.
 
Thanks a lot for the explanation in advance
Parents
  • I also follow JSlat's method "in to out". In case of suspension-body related bushes, I assume the bush inner ring as J-Part (Attached to the Body) and  the bush outer ring is as I-Part (Attached to Suspension component) 
    I also pay attention to the rig and fixture assembly on which the bush stiffness (Force - Deflection) curves are measured.
    For example, it is possible that in a Bush-A, the inner ring is fixed and the outer ring is deflected for measuring the force​. Where as in Bush-B, the opposite is done. In case of Bush-B, the measured stiffness curve needs to be inversed (multiplied by -1) before using it in bush formulation.
     
    On that note,  in the toe-link bushing example, have you inversed the stiffness curve when you change I/J parts? Does it still lead to different results after inversion? 
Reply
  • I also follow JSlat's method "in to out". In case of suspension-body related bushes, I assume the bush inner ring as J-Part (Attached to the Body) and  the bush outer ring is as I-Part (Attached to Suspension component) 
    I also pay attention to the rig and fixture assembly on which the bush stiffness (Force - Deflection) curves are measured.
    For example, it is possible that in a Bush-A, the inner ring is fixed and the outer ring is deflected for measuring the force​. Where as in Bush-B, the opposite is done. In case of Bush-B, the measured stiffness curve needs to be inversed (multiplied by -1) before using it in bush formulation.
     
    On that note,  in the toe-link bushing example, have you inversed the stiffness curve when you change I/J parts? Does it still lead to different results after inversion? 
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