applied displacement pattern with load limit (transient)

[gaziz]

Hi,

Is there any way, in transient analysis, to apply displacement pattern but have a load limit for it?

I'm using SSPbrickUP element to simulate undrained triaxial compression with own material. I'm applying displacement pattern:

set VdispInitial [nodeDisp 5 3]
set Vdisp -0.01
set Disp [expr $VdispInitial+$Vdisp]

set lValues [list $VdispInitial [expr $VdispInitial+$Vdisp] [expr $VdispInitial+$Vdisp]]
timeSeries Path 5 -time {0 100 1e10} -values $lValues -factor 1
pattern Plain 4 5 {
sp 5 3 1.0
sp 6 3 1.0
sp 7 3 1.0
sp 8 3 1.0
}
(nodes 5,6,7,8 are at the top of the element)
which works just fine, but I want it to reach certain load limit and stop there.

I know that I can use load pattern instead, but the problem with the load pattern is that it will introduce little perturbations in stresses (perhaps due to pore pressure dof) and my material is sentsitive to such perturbations.

Any idea?

[fmk]

you could of course monitor what is happening in the script and then when you reach the limit make the load pattern constant or remove it.

[gaziz]

fmk wrote:
> you could of course monitor what is happening in the script and then when you reach
> the limit make the load pattern constant or remove it.
>

Hi frank,

Thank you for your reply. So I guess there is a command that could read current load at a node, something similar to displacement reading?
"nodeDisp 5 3"
If there is any, can you help with it? I tried to google it and couldn't find anything.

Thank you again frank

[fmk]

there is nothing there at the moment .. there is the getTime command, that returns the pseudo time if a Linear pattern you can figure out nodal load, if a Path you would have to open the file and determin oload from points in the file