recorder

[Eli]

Hi
In time history analysis, I record columns forces as following:
recorder Element -file 1/Col_11_Force.out -time -ele 11 globalForce
and the result is:

0.02 -6084.52 4.13333e+006 19283.3 6084.52 -4.13333e+006 10560.5
0.04 -6084.52 4.13333e+006 19283.3 6084.52 -4.13333e+006 10560.5
0.06 -6084.52 4.13333e+006 19283.3 6084.52 -4.13333e+006 10560.5
0.08 -6084.52 4.13333e+006 19283.3 6084.52 -4.13333e+006 10560.5
0.1 -6084.52 4.13333e+006 19283.3 6084.52 -4.13333e+006 10560.5
0.12 -6084.52 4.13333e+006 19283.3 6084.52 -4.13333e+006 10560.5
…
The first column is time. Are the others columns forces in fx fy fz mx my mz directions?
Why they are constant in different time in each columns?

[fmk]

1) yes.
2) it's your model? the forces in the element are not changing. are the loads constant (constant timeSeries or loadConst issues)?

[Eli]

yes. the code is:

#time history analysis
wipeAnalysis
loadConst -time 0.0
source recorder.tcl
set outFile tb.tcl
set Nsteps 1400
set dt 0.02;
set GMfatt [expr 9.81];
set gamma 0.5
set beta 0.25;
system UmfPack
constraints Plain
test EnergyIncr 1.0e-4 1000;
algorithm NewtonLineSearch;
numberer RCM
integrator Newmark $gamma $beta
analysis Transient
set Gaccel "Series -dt $dt -filePath $outFile -factor $GMfatt";
pattern UniformExcitation 2 1 -accel $Gaccel;
analyze $Nsteps $dt;

1- so is the result force the maximum of element force during the time?
2-what is the difference between constant timeSeries and loadConst issues? are they both using in time history analysis?

[fmk]

if you have constant forces and the accelerations at the start of the file are not all zero then it is having problems opening the file you have .. or you have no nodal masses assigned.

[Eli]

This problem was solved. Thanks. But I have another question:
My model is 2D and I use recorder Element -file 1/Col_11_Force.out -time -ele 11 globalForce
Is the following true? (I mean directions)
Time fx fy fz mx my mz
0.02 -6084.52 4.13333e+006 19283.3 6084.52 -4.13333e+006 10560.5
If it is true, why fx=mx and fy=my ?

[jovillarroelb]

You have a 2D model. you only have 3 dof wich will result in fx, fy and mz the first three columns are at the begining of the element and the last 3 are at the end. The forces are the same because I asume your element is elastic.

Greetings!

[Eli]

thanks jovillarroelb.
dear fmk, is jovillarroelb's writing true?

[fmk]

yes ... you are asking for the global forces .. you obviously have a 2d frame with 3 dof at every node. this implies the beam element must have 6 forces at the end, 3 for each end node. this is your basic stiffness method.

[Eli]

in following recorder, there are 4 columns in result.
recorder Node -file 1/node1reac.out -time -node 1 -dof 1 2 3 reaction

91168.5 -17184.7 4.11348e+006 47643.6
182337 -28301.5 4.09362e+006 76003.1
273507 -39435 4.07377e+006 104362
364677 -50585.2 4.05391e+006 132720
...

the last 3 columns are node1 reactions in x,y and z direction. what is the first column?

[fmk]

pseudo-time, what a [getTime] command would return at time each record is made .. you have the -time option specified which is why you are getting it.

[Eli]

what is pseudo-time in detail?

[fmk]

in a transient analysis it can be thougt of as the time. in static analysis, calling it the time confuses people. in both, at each step in an analysis it is the time sent to the load patterns to apply their load at. in case of a plain load pattern, the load patterns in turn will get the load actor from the time series given this time, and will then use this load factor on the loads in the pattern. in uniform exciatation the pattern gets the acceleration from the time series for this time and then applies -mAg as forces at the nodes in dirn of motion.

[Eli]

How can I set maximum displacement of node 2 to MaxDisp?
set MaxDisp [? 2 1]
if i replase EnvelopeNodeDisp with ?, it gets following error:
invalid commamnd name "EnvelopeNodeDisp"

[fmk]

you need to rephrase the question as i can't understand what you are asking.

[Eli]

I need EnvelopeNode disp of node2 in this format:
set MaxDisp [nodeDisp 2 1]