optimumk help 1

[AniketModi]

I am working on analysis of front part(rear part excluded) of car in optimumk
in case of pure heave what is the axis of rotation?
is it whether axis passing through centre of car or centre of front wheel axis?

 

[AniketModi]

let me make it correct heave is a vertical linear motion but due to this motion wheels move towards each other i want to ask about the axis of rotation of the wheels
also in the analysis wheels are not leaving the ground why is it so?

 

[IRstuff]

Doesn't the rotation behavior of the wheel axle depend on the suspension design?

TTFN

FAQ731-376

 

[AniketModi]

yes, i am using double A Arm suspension system

 

[zekeman]

I think maybe you should explain clearly what you are trying to do and explain "heave" and the fact that the thing is not leaving the ground surprises you, since aren't you are analyzing the situation. Also, how do wheels "move toward each other"? Do you mean accelerate?
You can't get meaningful answers to such a vague question. As you can see, only some of us are mind readers.

 

[FeX32]

I read my bosses mind everyday


Fe

 

[AniketModi]

ok, heave is a vertical displacement of the centre of car, i am trying to minimise the camber in this software while changing the parameters like different rod lengths (chassis fore arm, chassis aft arm etc.). As centre goes up wheels come closer to the centre axis no matter how much you increase heave. doesn't this software show analysis when the whole body bumps off the road?

 

[GregLocock]

I think you will find that a picture is worth a thousand posts.


Cheers

Greg Locock

SIGlease see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[IRstuff]

Still really unclear. Why not just delete the ground altogether? Then the wheels should sag to the lowest possible point.

TTFN

FAQ731-376

 

[BrianPetersen]

Any independent suspension system with instant-centers above ground level will ALWAYS let the contact patches come closer together (in the side-to-side direction) as they drop down (i.e. body lifts). It is impossible for it to be otherwise.

If you want an independent suspension design that doesn't cause this and doesn't cause camber change with suspension travel, have a look at the double-trailing-arm suspension of the original air-cooled VW Beetle. If you copy that suspension design, perhaps you can achieve ride and handling characteristics not too different from a 1960's (designed 1930's) air-cooled Beetle. Is that what you are looking for?

Or perhaps you could switch to a solid axle leaf spring front suspension, since with those, even if the instant-center is quite high off the ground, the front wheels will remain the same distance apart and always perpendicular to the ground and always parallel to each other, no matter the bodyshell movement. Do you want to achieve the ride and handling characteristics of a '56 Ford F100?

Sometimes it's too easy to get hung up on something that "seems bad" even though in the grand scheme of things, it doesn't matter.

You need to explain what it is that you are trying to do and perhaps a little of WHY you are trying to do that. Double-wishbone suspension designs are extremely common and widely used. Depending on how you set them up, the ride and handling can be anywhere between '53 Buick and 2009 Formula 1 car.

 

[AniketModi]

thanks
i got a direction to think of
i will work on this more