Anti Sway Params

Discussion in 'Car Modding' started by Yoann56, Oct 19, 2020.

  1. Yoann56

    Yoann56 Registered

    Joined:
    Jan 16, 2012
    Messages:
    5
    Likes Received:
    20
    Hello,

    Could explain me how Anti Sway Params works ?
    An example of my hdv :
    FrontAntiSwayParams=(1,1,0)
    FrontAntiSwayBase=0
    FrontAntiSwayRange=(0,0,5)
    FrontAntiSwaySetting=2
    FrontAntiSwaySpecial=(0,"0","N/mm",0.0)
    FrontAntiSwaySpecial=(1,"207","N/mm",207151.0)
    FrontAntiSwaySpecial=(2,"291","N/mm",290661.0)
    FrontAntiSwaySpecial=(3,"435","N/mm",435234.0)
    FrontAntiSwaySpecial=(4,"688","N/mm",688030.0)
    FrontAntiSwayRate=(6e10,4)

    I know the diameter of my Anti Roll Bar and I've calculated with a finite element model the stiffness at the end of my Anti Roll Bar. I applied a load F at each end of my ARB in the opposite direction. It's right ?? Or I need to divide by 2 ??
    upload_2020-10-19_14-3-55.png

    And last question, could you confirm that the value in N/mm is the stiffness at the and of the Anti Roll Bar ? It's not the stiffness due to the Anti Roll Bar at the center of wheel ?

    Thanks in advance for your help
     
  2. mantasisg

    mantasisg Registered

    Joined:
    Aug 17, 2016
    Messages:
    2,926
    Likes Received:
    3,876
    Hello. Some good questions I suppose, perhaps slightly confusing. I don't have certainly correct answers, but I hope to still perhaps help somehow.

    First of all, in this awesome site there is some information about rF parameters: http://meetme.bplaced.net/rF2_onlineTools/ISI/PhysicsGlossary.htm, I suppose you knew it already. As well as explanations in skippy devmode files. Although there is always more to find out.

    I also wonder if you are mixing up anti sway bar torsional stiffness with actual torsional moment force acting on it. But I am confused myself too. I just assume that what is in rF physics parameters is like additional stiffness for a suspension just applied for roll motion and not for when both wheels have same compression/extension movement.

    Here are lines from skippy.hdv in devmode folder:

    FrontAntiSwayParams=(1, 0, 0) // Whether antisway bar is (0=diameter-based or 1=spring-based, detachable, adjustable on the fly)
    FrontAntiSwayBase=0.0 // Extra anti-sway from tube twisting
    FrontAntiSwayRange=(35000, 4000, 1) // Anti-sway rate to car center (asymmetric). This value should be half of what is provided in most car manuals (which generally use wheel to wheel rates)
    FrontAntiSwaySetting=0
    FrontAntiSwayRate=(1.36e11, 4.0) // (base, power), so rate = base * (diameter in meters ^ power) (not applicable for spring-based antisway)
    RearAntiSwayParams=(1, 0, 0) // Whether antisway bar is (0=diameter-based or 1=spring-based, detachable, adjustable on the fly)
    RearAntiSwayBase=0.0 // Extra anti-sway from tube twisting
    RearAntiSwayRange=(10000, 4000, 8)
    RearAntiSwaySetting=4
    RearAntiSwayRate=(1.36e11, 4.0) // not applicable with spring-based antisway

    As you can see rF can work out diameter or spring based simulation of anti roll bar. I suppose spring based is equal to what is applied at the center of the wheel, as there are no geometry paramters to define connection of the antiroll bar. And diameter based must be giving away resistance based on twisting of a thing.

    By the way just found this nice article including a formula to calculate anti roll bar stiffness, just resulting in pounds per degree,: https://www.wikiwand.com/en/Anti-roll_bar

    I also just found this calculator, I wonder if it is good. Seems very simple, which is not bad thing. Some units converting is needed. http://www.gtsparkplugs.com/Sway-Bar-Calculator.html
     
    Last edited: Dec 27, 2020

Share This Page