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View Full Version : how to constraint thickness of wall equal ?


GraceY
07-29-2004, 05:53 PM
See below, I want get the equal thickness of whole wall , then one thickness dimension was modified, others can automatically update.

I try to use Relation module, but I don't know how to do it.

Pls any body could tell me?
Thanks.

John Scheffel
07-30-2004, 08:55 AM
One way would be to set a Distance Variable and then assign the distance between the parallel faces to be equal to that variable. Then if you change the variable value they would all change when you Solve the relation set. The attached GIF shows an example. I created a distance variable vdist1 and set it to 20. Then I created 4 distance relations and set them to use an Expression (formula) equal to vdist1.

May Kung
07-30-2004, 09:37 AM
John beat me to it. :) I was wondering, though, if it makes any difference which plane you select first when defining a distance relation. I would imagine it would be best to keep consistent based on which face should be held fixed and which is allowed to float.

John Scheffel
07-30-2004, 10:29 AM
I don't know if the order makes a difference, but it would be advisable to put additional contraints on the geometry to make sure it modifies the way you want. For example, if you want the outside dimensions to remain fixed while the wall thickness changes, they you should add constant distance relations on the outside faces. Likewise if you wanted the inside dimensions to remain the same. But you can't do both or the model will be overconstrained. When using relations it is safest to fully constrain, but not over constrain, otherwise you might get unexpected results when you solve.

GraceY
07-31-2004, 11:26 AM
Thank you John and May. I got it.