Need some help in setting boundary conditions in Abaqus

[Jeremy1989]

Hi everyone,

Hope someone can help me on this.

I am trying to model a slice model of an electronic chip that is undergoing thermal fatigue.

As this has been done frequently by researchers, I came across a lot of paper which state how they set the boundary condition of the chip. You can refer to the picture that I have attached for reference.

What I am unclear of is, how do they specify the boundary conditions of 'UY coupled on all plane surfaces' and 'UX coupled on PCB vertical surface'

To quote the author for the rationale of these 2 boundary conditions:
'The opposite side of the diagonal symmetric plane is neither a free surface nor a true symmetry plane. A reasonable compromise is to couple the y-displacements of the nodes on the slice plane. The effect of this constraint is that the slice plane is free to move in the y-direction, but that the surface is required to remain planar. '

But how do I set these 2 boundary conditions in Abaqus?

I would greatly appreciate any advice. Thank you

Regards
Jeremy

 

[Jeremy1989]

Apology for the broken link, this one should work

http://i46.tinypic.com/25uk3li.png

 

[burningDiesel]

I don't 100% get the problem, but what you are looking for is more than likely:
31.2.1 Linear constraint equations i.e. the *EQUATION keyword.

 

[Jeremy1989]

Thanks sdebock for your reply

Sorry maybe I am not clear in my problem.

Let's say I want a particular plane surface called A, to be able to move in the y direction, but I want that surface to remain planar when moving in the y direction.

I think I should be using kinematic coupling constraint under interaction module? But I was told to specify the control point so I created a reference point in the middle of that plane surface A and set it as my control point. As for surface, I selected the entire plane surface A. Then, I select U2.

So I believe by setting in such a way, all the nodes on the plane surface A will move together in the same displacement in the y direction (ie, plane surface A will remain planar when moving in the y direction).

I am not sure whether I am doing it right. I am not very sure how does the linear constraint equation works even after reading the manual. Could you provide me with some advice?

Much thanks

 

[rstupplebeen]

Create a kinematic coupling constraint for the face constraining the DOF you want to remain planar to a reference point.

Rob Stupplebeen

https://sites.google.com/site/robertkstupplebeen/

 

[Jeremy1989]

Thanks rstupplebeen for your reply,

but what does a reference point mean? Can I set it in the center of the plane?

Thank you

 

[IceBreakerSours]

See the CAE manual for figuring out how to assign a reference point. Yes, you may set it anywhere.

http://www.eng-tips.com/faqs.cfm?fid=376

http://www.eng-tips.com/faqs.cfm?fid=1083