Load steps

[In-igo]

Could somebody tell me why in my model the load is applied in 1 single step? I write "analyze 10" to perform the analysis but in the 10 steps is written the same response in the recorders. Thank you.


SCRIPT


model basic -ndm 2 -ndf 3

# nodes
node 1 0.0 0.0
node 2 0.0 400.0
node 3 300.0 550.0
node 4 600.0 400.0
node 5 600.0 150.0

# Constraints
fix 1 1 1 1
fix 5 1 1 1


# Material
# Steel S-275
set E 210e2; # Young
set fy 27.5; # fy=275 N/mm2 = 27.5 kN/cm2

# id fy E0 b
uniaxialMaterial Steel01 1 $fy $E 0.01


# Fiber section

set d 16; # nominal depth
set bf 8.2; # flange width
set tf 0.74; # eflange thickness
set tw 0.5; # web thickness
set nfdw 6; # number of fibers along web depth
set nftw 1; # number of fibers along web thickness
set nfbf 1; # number of fibers along flange width
set nftf 2; # number of fibers along flange thickness

set idsec 1

source Wsection.tcl
Wsection $idsec 1 $d $bf $tf $tw $nfdw $nftw $nfbf $nftf



# Elements

geomTransf "Linear" 1

# integration points
set np 5

# Create structure. "House-shape" steel frame
# id ndI ndJ nsecs secID transfTag
element nonlinearBeamColumn 1 1 2 $np $idsec 1
element nonlinearBeamColumn 2 2 3 $np $idsec 1
element nonlinearBeamColumn 3 3 4 $np $idsec 1
element nonlinearBeamColumn 4 4 5 $np $idsec 1


# Load Pattern
# Some variables
set CargaDistr -20.0e-2; # 20 kN/m = 0.2 kN/cm
set alfa [expr atan(1.5/3)]
set DistrPerp [expr $CargaDistr*cos($alfa)]
set DistrAxial [expr $CargaDistr*sin($alfa)]

pattern Plain 1 "Linear" {

eleLoad -ele 1 -type -beamUniform $CargaDistr 0.0
eleLoad -ele 2 -type -beamUniform $DistrPerp $DistrAxial
}


# ANALYSIS


system BandGeneral

#constraints Plain
#constraints Penalty
constraints Transformation

#numberer Plain
numberer RCM

test NormDispIncr 1.0e-10 12 2

algorithm Newton

integrator LoadControl 0.1

analysis Static


# Recorders

recorder Element -xml ElementosEj82.out -time -ele all globalForce
recorder Node -xml DespNodosEj82.out -time -node 2 3 4 -dof 1 2 3 disp
recorder Node -xml ReacNodosEj82.out -time -node 1 5 -dof 1 2 3 reaction

recorder display Deformada 10 20 400 400 -wipe
vup 0 1 0
vpn 0 0 1
prp 0 0 1
viewWindow -1000 1000 -500 800
display 1 0 3


# Perform analysis

analyze 10

print ele

[silvia]

please check it against the examples in the examples manual

[In-igo]

I have been looking through plenty of examples and I have compared them with my script. I just can't find what is wrong. The nodes, constraints, material, fiber section, elements and load pattern are correctly defined. The analysis parameters too (I've checked them again and again comparing them to the examples).
I have read in another post that the eleload command could give some problems when using nonlinearBeamColumns. This is my case, but I don't know what this has to do with applying the load in a single step although I write 10 load steps.
Thank you for your time and your help.

[silvia]

do you have convergence problems at all?

[In-igo]

Not any more. I had convergence problems when the fiber section was smaller, but I changed it to a bigger one and now everything works correctly. It takes 5 iterations to reach the tolerance in the first step but all the others only take 1.

I know the data output is correct since I have tested the model with elastic sections and it's quite similar.

The problem still is the load steps. You can see it performs the 10 of them but it applies the complete load in the first.

For example, this is the node diplacement recorder:

<Data>
0.100000 15.259791 -0.097594 -0.016515 15.043177 0.279002 0.014647 14.803628 -0.071840 -0.041876
0.200000 15.259791 -0.097594 -0.016515 15.043177 0.279002 0.014647 14.803628 -0.071840 -0.041876
...
1.000000 15.259791 -0.097594 -0.016515 15.043177 0.279002 0.014647 14.803628 -0.071840 -0.041876

What could be wrong? Thanks again for any help you can give.

[silvia]

how about removing those quotes around Linear? i don't see them in my example manual.

let me know if it works.

[In-igo]

Still the same... Any other ideas?
I have been racking my brains for a few days but I can't find what's wrong. Does the problem with the eleload command and the nonlinearbeamcolumn elements persist? Could this be the problem? If so, how can I mend it? Again, thanks a lot.

[In-igo]

Just for "fun" I've tried a displacement controlled integrator and the load has been applied correctly in the number of steps I write, so the problem isn't the eleload command and nonlinearbeamcolumn elements. The only thing I found strange is that the time column in the recorder has negative (-) values. Does this give you any clue?

[silvia]

why is your test a displacement increment test????

[In-igo]

No, no, no. It isn't a displacement increment test. I was just playing around with the model . However, the load was correctly applied. By this I mean that I could see how the model was moving step by step.
In the real test (load control integrator) the load isn't applied the way I want to yet. I'm still asking for help, please don't give up.

[silvia]

please send me your files
opensees-support at berkeley dot edu

[Saseydon]

Im using the CCS Compiler V4.077 as a Plug-In in the MPLAB IDE V8.14. I can load the application about the MPLAB ICD2 into the PIC24.

But if I want to use the Load-N-Go to load the same application into the PIC24, I get no error the green LED is flickering until the green LED is ON but the application is not running.

Could somebody help me, please?


Regards
Jochen

[silvia]

please ask this question on the framework page.