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Thank you dear fmk,
I found the problem in input units.

Hi dears, I am trying to to model 3d steel structure with soil interaction. i've modeled soil with "stdBrick" element and "PressureDependMultiYield" nDMaterial. number of dofs for structure is 6 and for soil is 3. I fixed rotational dofs of base nodal of structure and I used equalDOF for translation...

if you are using nonlinearBeamColumn element, use "-iter" option at the end of the element command. the iterative form can improve the rate of global convergence at the expense of more local element computation.

salam, You can use "for loop" to overcome this issue. First define displacement increment using sp command. In for loop specify "integrator LoadControl $dLambda1". set dLambda1 to desire quantity. This is a simple example: ... sp 1001 1 1 ... for {set i 1} {$i<10} {incr i} { set dLambda1 [expr 0.1*$...

I have installed CUDA Toolkit 5.5 package, also I've downloaded "CuSP library" in zip format but I don't know how to Install the CuSP library and where I should put the .dll file!

if you calc the drift between the 2 nodes they are non-zero and i'm sure that prepDirn is correct.
recorder Drift -jNode 501 -iNode 502 -dof 2 -prepDirn 3
my plan is in 1-2 plane and 3 is the prepDirn , i use to various nodes but always i got error

yes, i got the same eigenvalues for 2 first modes, and so on for 4th and 5th modes

thank you for your attention.
yes, i have non-zero value for that nodes displacements

hi fmk, i've got the same error but i'm sure that nodes exist and prepDirn is ok.
my model is 3D and when I use your code i didn't get any error but i got zero for nodeDisp

hello, when I use [eigen 5] in 5-story 3D concrete frame included fiber section, it's modes are same as SAP result, but when i use [eigen 1] i get this error: "ArpackSolver::Maximum number of iteration reached." and about [eigen 9] or greater number i get this error: "ArpackSolver::Error with _saupd...

I found the problem where I applied gravity load bud i didn't do gravity analysis before dynamic analysis, and my structure don't fail in large time duration now. my new question is: To take into account first order treatment of geometric nonlinearity we use 'Linear Transformation' and to take into ...

dear fmk, thanks for your attention. I'm trying to employ IDA for SAC 9-story moment frame building that was applied previously by Vamvatsikos and Cornell, 2003a. the criteria that was expressed is max. interstory drift ratio.I use exactly the same procedure namely 'hunt & fill'. I was successful to...

Hi, I used to perform dynamic analysis with various time duration, but every time I got various response. Let me explain more... I want to perform IDA, moreover my model include P-Delta effect using geometric transformation 'PDelta'. Earthquake time duration is 40s, In high scale ground motion say S...

Hi, dear mrtdpg, I have the same problem as you. my IDA curve in not linear but it has not flatline at the end! I used fiber section, I guess there is a problem here!
can any body help me?
dear ToBeLignos, how did you solve it?
dear martinmasanes, have you found out where the problem is?