Spring and Damper

silvia · Post by **silvia** » Fri Nov 30, 2007 8:39 am

okey. then something else is causing the singular matrix.

zhenxinli1999 · Post by **zhenxinli1999** » Fri Dec 07, 2007 5:22 am

silvia wrote:okey. then something else is causing the singular matrix.

If I only simulate the longitudinal that's ok.
If I use the Zero-length Element that's ok.
So I think the other scripts are ok. I am confused....

silvia · Post by **silvia** » Fri Dec 07, 2007 6:14 am

when you use the zero-length, do you constrain the other dofs??

zhenxinli1999 · Post by **zhenxinli1999** » Fri Dec 07, 2007 10:16 pm

NO. The same as above.
When I use ther zeroleng element the following commands are used.

equalDOF 147 1 3 4
uniaxialMaterial Steel01 1 331.2 165600 0.01
uniaxialMaterial Steel01 2 331.2 165600 0.01
element zeroLength 1001 1 147 -mat 1 2 -dir 1 2

silvia · Post by **silvia** » Sat Dec 08, 2007 8:28 pm

that's the problem, then, you need to specify some sort of constrain between the dofs 5 and 6, right?

zhenxinli1999 · Post by **zhenxinli1999** » Sun Dec 09, 2007 1:13 am

But I only need to simulate the longitudinal and transversal hysteretic relation(shear direction) of bridge bearing.
When I use ther zeroleng element without specifying the constraints of 5 and 6 direction the result is reasonable.