$dir in zerolength element is global rather than local?

macropaine · Post by **macropaine** » Sun Jul 26, 2009 8:18 pm

I use the zerolength element with hysteretcial material to model shear-slip nonlinear spring. It is found that the $dir in zerolength element is not local as the manual instrut. It is global, isn't it ?
thanks

silvia · Post by **silvia** » Sun Jul 26, 2009 9:29 pm

they should be in global axis, but, for some reason, always in 6 dofs

macropaine · Post by **macropaine** » Mon Jul 27, 2009 3:18 pm

Thank you Silvia. The manual says it is local. It puzzle me for a few days.

Now it is clear.

silvia · Post by **silvia** » Mon Jul 27, 2009 3:33 pm

whatever the manual says -- i "wrote" it....

solmaz_moradpoor · Post by **solmaz_moradpoor** » Wed Apr 21, 2010 10:08 pm

hi
i try to model tuned mass damper in 3 building with 3,9 and 20 storey
after many time i could model stiffness and damper in a node with element zeroLength.now i am not sure about dir.because i want to model translational spring and i think i shuld to use dir 1, but give error .when i use dir 6 my model runs whitout any problem.
do correct in a model 2d to use dir 6?

my scripts:
set K 47338.2;
set C 10648.8;
set alpha 1;

uniaxialMaterial Elastic 3 $K
uniaxialMaterial Viscous 4 $C $alpha;

element zeroLength 28 12 122 -mat 3 -dir 6;
element zeroLength 29 12 122 -mat 4 -dir 6;

what is your suggest?
thanks for your attention.

Post by **fmk** » Thu Apr 22, 2010 10:02 am

6 is rotation about z axis.