Problem on Boundary Conditions

aminrahmani · Post by **aminrahmani** » Sun Mar 01, 2009 2:37 pm

Hi everybody,

I apply boundary conditions on soil nodes for the first stage of analysis. Then for the second stage I apply other boundary conditions.

My problem is that the results show that in the second stage the first boundary conditions are used. How can I solve the problem?

Thanks for your help

Post by **fmk** » Mon Mar 02, 2009 11:12 am

remove the boundary conditions after the first analysis .. either put them inside a load pattern and remove the load pattern or remove the individual sp constraints.

remove loadPattern tag?
remove sp nodeTag? dof?

aminrahmani · Post by **aminrahmani** » Mon Mar 02, 2009 11:34 pm

Hi ,
I put the boundary conditions in a load pattern, but I got the previous results again. Boundary conditions in first stage are :

pattern Plain 1 "Constant" {

for { set i 1 } { $i <= $nodeNum } {incr i 1} {
fix $i 1 1 0
}
fixZ 0.0 1 1 1 -tol 1e-10
}

As you said, after the first analysis I removed the first boundary conditions as follows:

remove loadPattern 1

And then the second boundary conditions are applied.
Is it right?

Thanks.

Post by **fmk** » Tue Mar 03, 2009 7:44 am

at the moment you can only use the sp command to add single point constraints to a load pattern .. the commands fix and fixZ add them to the overall Domain and not to the LoadPattern .. i never imagined anybody wanting to do this but i will make the change in the next version.