Problem with stressStrain recorder for zeroLengthSection

[Deniz]

Silvia,

I cannot monitor stress-strain response of a zeroLengthSection element. I get a blank screen (no output) while performing a simple moment-curvature analysis. The script is based on opensees manual's script util. lib.

Is there a limitation for this element type or am I doing something wrong?

Thank you in advance.

Here are the related portions of script:

# Units in KN m
# Cover Concrete - C10
set Ec1 24277.0e3;
set fck1 -10.0e3;
set fcu1 -8.5e3;
set eco1 -0.0008;
set ecu1 -0.003;
uniaxialMaterial Concrete01 1 $fck1 $eco1 $fcu1 $ecu1;
# RC_Rsection $id $h $b $cover $coreID $coverID $steelID $numBars $barArea $nfCoreY $nfCoreZ $nfCoverY $nfCoverZ;
RC_Rsection 1 0.3 0.3 0.015 1 1 101 \
2 1.54e-4 \
30 30 3 3;
element zeroLengthSection 1 1 2 1;
recorder Element -file Out/StressStrain.txt -ele 1 section 1 fiber 0.135 0.0 1 stressStrain;

[silvia]

make sure your RC_section procedure is done properly.
also, what analysis do you submit it to?

[Deniz]

Silvia,

It was a simple moment curvature analysis of a rectangle section. But, I think I have figured out the problem. Changing script into following form solved the problem. In other words omitting section number is a "must".

previously:
recorder Element -file Out/StressStrain.txt -ele 1 section 1 fiber 0.135 0.0 1 stressStrain;

now:
recorder Element -file Out/StressStrain.txt -ele 1 section fiber -0.135 0.0 1 stressStrain;

However, one point is still unresolved. I have found that compression side of the rectangular section remained at the bottom instead of top according to right hand rule; based on local XS coordinates (i.e. positve moment about local z axis??? is it?). Hence I had to put -0.135 for y local ordinate.

The point is that it is rather confusing to utilize global force vector on local XS ordinate and/or abscissa.

Regards.

NOT: Rectangle XS fiber construction is again from opensees command language manual.

[silvia]

i think that may actually be a bug that has recently been fixed.
it is a holiday here, so frank may not confirm this until monday.
silvia

[Deniz]

Happy thanksgiving.