How to constrain nodes in positive axis only? (I-deas Master series) 3

[kar99429]

Hi guys,

I am trying to constrain(arrest) the movement of a bracket surface in positive direction only(say Y-axis) and let it to be free in -Y axis.and it has to be free in all another axes.

I need to do so , beause the surface i need to arrest , as said above is in contact with other part.Just like anti rotation flange.

Is there any option in I-deas software for this..

Please help me..

 

[GregLocock]

Sounds to me like you need to investigate a non linear model, ie contacts. You cannot perform a linear FEA on constraints like that.

Cheers

Greg Locock


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[kar99429]

thanks greg for ur reply..

But i am doing linear analyis only..

Ok.. how anti rotation flange can be simulated in FEA.. i mean what kind of restrains i have to give..

 

[GregLocock]

Thanks for the star... but you can't do contact problems in a linear model.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?

 

[kar99429]

Am confused in this linear , non linear model concept.. i thought that linear is regarding to material like steel and non linear to steel. but now i feel that my understanding is wrong..

Please anyone clarify this linear, non linear concept

 

[Drej]

You can have "linear contacts" in a model (ie tied contact) but in reality these are not a true contact condition and are usually achieved by linear constraint equations or derivations thereof.

Non-linearities in a model can be introduced by materials (eg plasticity), geometry (ie non-linear geometry such as displacement-dependent stiffness or large strain/displacement) or through other changes in model stiffness (ie contact, such as stick-slip). As mentioned, you will likely need to consider some form of non-linearity to achieve what you need - the good old-fashioned gap element might suit your needs here.


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[crisb]

Gap elements?

http://www.kxcad.net/ugs/SDRC_I-DEAS_NX_series_Help_Library/ele_ug/ch31.htm

 

[kar99429]

thanks drej, crisb..
I found one element type called "constrain elements" in I-deas SDRC.
Will it be possible to solve that contact issue.
If not please consider any method to simulate this..

I am attaching the illustration i need to constrain.

 

[kar99429]

hi.. please anyone reply for my above post...
i need ur help..