Search found 5881 matches

by fmk
Mon Feb 26, 2024 9:14 am
Forum: OpenSees.exe Users
Topic: Question about the weird variaiton of axial force at pier base during a nonlinear time history analysis
Replies: 7
Views: 3514

Re: Question about the weird variaiton of axial force at pier base during a nonlinear time history analysis

to original poster .. what convergence test are you using .. i suggest NormUnbalance if you are not using it .. NormDispIncr is pretty much useless in dynamic analysis if you want to ensure equilibrium
by fmk
Mon Feb 26, 2024 9:06 am
Forum: OpenSees.exe Users
Topic: Inclined supports.
Replies: 1
Views: 480

Re: Inclined supports.

simplest might be to orient the structure at 45 degrees and use normal constraints .. create a little function to return the transformed coordinates for the nodes and use those when creating the nodes or just use [expr ] in the nodes directly.
by fmk
Mon Feb 26, 2024 8:57 am
Forum: OpenSees.exe Users
Topic: Fiber sections
Replies: 1
Views: 475

Re: Fiber sections

i suggest you try it and spit out the fibers and their locations to see what you generated. if you have complicated sections i suggest building the section i fiber at a time .. if repeated complex shaped sections, create procedures to do this.
by fmk
Mon Feb 26, 2024 8:53 am
Forum: OpenSees.exe Users
Topic: Outputs for damping forces
Replies: 2
Views: 330

Re: Outputs for damping forces

the only way to determine damping forces when using modal damping is to determine from global equilibrium .. it is a pain to do but you need to record the ground motion, all nodal accelerations for which there is a mass, and the element end forces .. create a free body diagram and then utilize the f...
by fmk
Mon Feb 26, 2024 8:44 am
Forum: OpenSees.exe Users
Topic: Axial force of column section is very small. Why?
Replies: 1
Views: 409

Re: Axial force of column section is very small. Why?

the fact that section axial force and element axial force is not consistent is a result of how the element force is calculated for a DISPLACEMENT based element" .. basically loop over all the gauss points in the element and combine the forces using the forces at the gauss points and the gauss point ...
by fmk
Mon Feb 26, 2024 8:27 am
Forum: OpenSees.exe Users
Topic: UmfPack error in retaining wall Analysis
Replies: 1
Views: 533

Re: UmfPack error in retaining wall Analysis

try changing solver to ProfileSPD and respond with the error you get when you run it
by fmk
Mon Jan 30, 2023 9:11 am
Forum: Documentation
Topic: Copyright terms explanation required
Replies: 12
Views: 16574

Re: Copyright terms explanation required

By PEER cbrinck means myself, the original developer of OpenSees and the person who last updated the copyright. The above license requirement for companies offering the opensees application as an online service you pay for, just mentioned by ponczek, is required as the UC lawyers have determined tha...
by fmk
Mon Mar 14, 2022 9:41 am
Forum: OpenSees.exe Users
Topic: LoadConst
Replies: 6
Views: 9389

Re: LoadConst

yes. it just sets aflag in the LoadPattern that tells it to keep the load multiplier the same from here on out.
by fmk
Tue Nov 09, 2021 9:13 pm
Forum: OpenSees.exe Users
Topic: Pushover analysis
Replies: 1
Views: 5080

Re: Pushover analysis

i suggest you post a simple example outlining your problem .. you have provided not enough information to provide any guidance .. as you are a newbie, a simple problem will force you to understand how OpenSees works and will hopefully enlighten you as to the mistake you are making.
by fmk
Thu Nov 04, 2021 9:42 pm
Forum: Parallel Processing
Topic: Accuracy of OpenSeesMP results
Replies: 1
Views: 8331

Re: Accuracy of OpenSeesMP results

The programs will not give the same results. Typically the difference is small, a difference in some insignificant digits. Hoewever if matrix is poorly conditioned at stages in a nonlinear analysis the results can be larger at the end. Check on differences after first few steps, if very different yo...
by fmk
Tue Nov 02, 2021 10:41 pm
Forum: OpenSees.exe Users
Topic: WARNING RandGenLinLapackSolver::solue() -LAPACK routine returned 487
Replies: 1
Views: 5967

Re: WARNING RandGenLinLapackSolver::solue() -LAPACK routine returned 487

error codes returned from lapack at start of analysis indicate the model is incorrect .. try a ProfileSPD solver and a PlainNumberer to see what dof has a problem, example: model basic -ndm 2 node 1 0 0 node 2 0 10 geomTransf Linear 1 element elasticBeamColumn 1 1 2 10 100 1000 1 fix 1 1 0 1 timeSer...
by fmk
Tue Nov 02, 2021 10:27 pm
Forum: OpenSees.exe Users
Topic: 2 Phase pushover analysis
Replies: 3
Views: 7766

Re: 2 Phase pushover analysis

here is a simple script that does what you describe w/o error (hopefully). It is impossible to figure out your problem with code in other files. Hopefully you can sort out your issue from code below. If not repeat your problem in a SIMPLE example like below. model basic -ndm 2 node 1 0 0 node 2 0 10...
by fmk
Tue Nov 02, 2021 9:48 pm
Forum: OpenSees.exe Users
Topic: How can get a list of all element tags of a specific type?
Replies: 1
Views: 5644

Re: How can get a list of all element tags of a specific type?

it is not a feature that is available from the command line .. it is of course something you could do in your script that creates the model
by fmk
Mon Nov 01, 2021 10:23 pm
Forum: OpenSees.exe Users
Topic: Maximum Node Displacement
Replies: 1
Views: 5687

Re: Maximum Node Displacement

you either have to look after the variable in your script, i.e. monitor the nodal displacements and write to a file when done, or use the EnvelopeRecorder. What is wrong with using the EnvelopeRecorder? you could also use the Envelope recorder, isssue a remove recorders command when analysis is done...