add a node during a transient analysis

[hoseinrezaei]

Hello my friends.
I have added a node in middle of a brace in an active braced frame and got this warning, why?
Thanks.

for {set i 1} {$i<6564} {incr i} {
analyze 1 0.005
if {[expr abs([nodeDisp 4 1])]>0.06} {

puts "[getTime] [nodeDisp 4 1]"
remove node 5
node 5 1.5 1.5
element truss 4 1 5 $ABrace $MatBrace
element truss 5 5 4 $ABrace $MatBrace

analyze 1 0.005
set i [expr $i+1]
remove element 4
remove element 5
# remove node 5
}


}




WARNING BandGenLinLapackSolver::solve() -LAPACK routine returned 7
WARNING NewtonRaphson::solveCurrentStep() -the LinearSysOfEqn failed in solve()
DirectIntegrationAnalysis::analyze() - the Algorithm failed at time 2.255
OpenSees > analyze failed, returned: -3 error flag

[fmk]

if the question is why does the analysis fail after the node was added .. i am guessing here based on your comments that this is a braced frame, 3 dof's at the nodes, as a consequence the new node needs to be constrained against rotation due to fact that only truss elements connect to it and you are not doing this.

[hoseinrezaei]

Thanks for your reply.
it was done.
How can I record force in truss element?
I have used element recorder before analysis but the output file has a column and that is time .

recorder Element -file Data/4.out -time -ele 4 force

[hoseinrezaei]

Thanks for your reply dear fmk.
it was done.
How can I record force in element which will be defined in each step of analysis, in this example when the element recorder was used the output file is contain 1 column and it is time and there isn't force columns, why?

recorder Element -file Data/4.out -time -ele 4 force

for {set i 1} {$i<6564} {incr i} {
analyze 1 0.005
if {[expr abs([nodeDisp 4 1])]>0.06} {

puts "[getTime] [nodeDisp 4 1]"
remove node 5
node 5 1.5 1.5
element truss 4 1 5 $ABrace $MatBrace
element truss 5 5 4 $ABrace $MatBrace

analyze 1 0.005
set i [expr $i+1]
remove element 4
remove element 5
# remove node 5
}


}

[fmk]

the recorder command only looks at when it is created to see if elemenets exist, so if you add elements later they are ignored. If you want to record forces of elements you aeadding and removing i suggest you do so in the tcl script using the eleResponse and puts commands.