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Hello, I am modelling an unbonded post-tensioned tendon in a concrete wall with a truss element using Steel02 material, with an initial stress of 69.2 ksi: set initStress 69.2 "uniaxialMaterial Steel02 $PT 245.0 [expr (245.0/0.0086)] [expr (((270.0-245.0)/(0.04-0.0086))/(245.0/0.0086))] 18 0.92...

Hello, I am modelling an unbonded post-tensioned tendon in a concrete wall with a truss element using Steel02 material, with an initial stress of 69.2 ksi: set initStress 69.2 "uniaxialMaterial Steel02 $PT 245.0 [expr (245.0/0.0086)] [expr (((270.0-245.0)/(0.04-0.0086))/(245.0/0.0086))] 18 0.92...

Hi Vesna, I am trying to compare the input energy vs damping energy using this recorder. Based on Dynamics if I calculate the cumulative input energy and also damping energy, at the end of earthquake they should be equal (based on conservation of energy, where kinetic and potential energy are almost...

Hi, I have a quick question about gap material: I have a prestressed rocking shear wall. If I want to model the rocking interface with only compression springs, is this command "uniaxialMaterial ElasticPPGap $matTag $E $Fy $gap <$eta> <damage>" exact enough to express all the compressive s...

How about if we define two nodes at base connecting with a zero length element, modeling a rotational spring. Using uniform excitation pattern, which of these nodes base acceleration is applied?

Sure; Thanks, Here is the command: node 1 0.0 0; # node#, X Y node 2 0.0 0; node 3 0.0 168; fix 1 1 1 1 ; # node DX DY RZ equalDOF 1 2 1 2 ; uniaxialMaterial ElasticMultiLinear 1 -strain -0.03 -0.02 -0.01 -0.0075 -0.0050 -0.0025 -0.0015 -0.0010 -0.000057 0 0.000057 0.0010 0.0015 0.0025 0.0050 0.0075...

Dear Vesna,
When I define a multilinear elastic spring at the base of the specimen, for a linear system I expect to get the same force-displacement behavior curve from OS result. But it is not happening. Is it possible that I mail you some results to find out the problem?
Many Thanks

I have a SDOF system, but a rotational spring is defined at base to model the multilinear elastic behavior of the system. Do you think I should just use one of these coefficients (Mass or Stiffness?) since it makes lots of change in the results.

Thanks Vesna,

Hi, I have modeled a rotational spring at the base of a rocking wall, using zero-length element, like: "element zeroLength 1 1 2 -mat 3 -dir 6 -doRayleigh 1" For the material (-mat 3) I am using two parallel springs: One of them represents a type of steel connector which is going to model ...

While I start running, it hangs and does not go on. When I delete half of points, it starts running but cannot still finish the analysis. That's why I was thinking there should be a limit on the number of points in "uniaxialMaterial ElasticMultiLinear".

Thanks, I will try that.

When I run it, it hangs and do not work, since I close the program

So, is there anyway I can change damping coefficient based on current stiffness?

No, Just stops working and I should quit. I was thinking it is due to the large number of points we have during earthquake.