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Hi all... can anyone please let me know how to record output from fibers? Let's say, I want to read stresses and strains from selected fibers in the problem described in the MomentCurvature.tcl script (http://opensees.berkeley.edu/wiki/index.php/Moment_Curvature_Example). When I add the following li...

Did somebody worked how to interpolate shell stresses from gauss points to nodal points? I've tried a simple 2D interpolation using matlab, but when comparing the stresses of two elements with common nodes, it can be seen that the error is very high using this interpolation. I guess I'll have to use...

Hi..

Is there a way to export the stiffness matrix of a model from opensees to a .txt file?

Thanks!

Thanks for the reply Vesna. If you mean use "Node recorder -reaction", that doesn't work, because I get the results shown above: 0 0 0.0011 -1.2991 0.0083 0 0 0 0.0011 1.2991 0.0083 0 0 0 0.0011 -1.2991 -0.0083 0 0 0 0.0011 1.2991 -0.0083 0 for the supported nodes. So, how can I get "...

Hello.. I'm trying to run a model with a large number of degrees of freedom (I have 4190 nodes). Is there a way to condense desired degrees of freedom in such a way that I can run a dynamic analysis in a short time? Currently I'm trying to run a dynamic loading situation, where a load takes 3 second...

When I change the type of constrain to equalDOF 2 8 1 2 3 4 5 6 equalDOF 22 13 1 2 3 4 5 6 equalDOF 21 11 1 2 3 4 5 6 equalDOF 1 5 1 2 3 4 5 6 equalDOF 4 7 1 2 3 4 5 6 equalDOF 24 20 1 2 3 4 5 6 equalDOF 23 19 1 2 3 4 5 6 equalDOF 3 6 1 2 3 4 5 6 The output of the nodes 1-8 is 0 0 0.0011 -1.2991 0.0...

Hello. The code provided below intends to simulate a loaded deck over a bridge. The deck is modeled using shell elements, and the girders are modeled using beam elements. The deck is connected to the girders through rigid links. The load over the deck is 40 kip, and the vertical reactions at the sup...

vesna wrote: > To me it looks like the analysis is hanging somewhere (it got stuck). > > For large models use Sparse solvers (e.g. UmfPack). Your tolerance may be > too low. I would not go lower than 1e-8. > > make use of "puts" command to check the progress of your > analysis. Do your anl...

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Hi everyone, I have a model with +4100 nodes, containing elastic beam elements and shell MITC4 elements. I'm trying to make a time history analysis but it's taking very long, which seems weird to me. I'm using the following analysis options: integrator Newmark 0.5 0.25; test EnergyIncr 1.0e-12 10 0 ...

Here's is a test: Cantilever beam, section 0.2x0.3 m2, L=10m, E=24GPa, G=10GPa, Ro=2400kg/m3; Izz=4.5e-4, Iyy=2e-4, J=4.695e-4. The stiffness and mass matrices are: K = [ E*A/L, 0, 0, 0, 0, 0] [ 0, 12*E*Iy/L^3, 0, 0, 0, -6*E*Iy/L^2] [ 0, 0, 12*E*Iz/L^3, 0, 6*E*Iz/L^2, 0] [ 0, 0, 0, G*J/L, 0, 0] [ 0,...

Hi there
I'm trying to perform model updating, for which I need eigenvalues and eigenvectors. The first ones are output in ascending order, but the eigenvectors have not the same output order as the eigenvalues. Is there a way to associate the output eigenvectors to the output eigenvalues? Thanks!

The problem seems to be in the definition of the geometric transformation. Thanks again!

vesna wrote: > Rigid links are only MP_constraint objects. They are not elements. In your > model you do not have enough elements. Instead of having element that goes > from 3 to 4 you need two elements: one that goes from 3 to 5 and another > from 5 to 4. You also need an element to connect two col...

Hi there. I'm trying to create a model which includes rigid links, but I'm constantly having the error: ProfileSPDLinDirectSolver::solve() - aii < 0 (i, aii): (2, 0) WARNING NewtonRaphson::solveCurrentStep() -the LinearSysOfEqn failed in solve() StaticAnalysis::analyze() - the Algorithm failed at it...