Search found 888 matches

by selimgunay
Tue Jul 20, 2021 9:15 am
Forum: OpenSees.exe Users
Topic: Modelling of columns subjected to large axial force
Replies: 2
Views: 37

Re: Modelling of columns subjected to large axial force

How are you modeling the braces and beams? If you have them elastic, that may be the reason of large axial forces.
by selimgunay
Mon Jul 19, 2021 10:08 pm
Forum: OpenSees.exe Users
Topic: How to release moment at the ends of a rigid link?
Replies: 7
Views: 216

Re: How to release moment at the ends of a rigid link?

You can replace one of the equalDOF with a zerolength element that has quite large stiffness except the rotational DOF.
by selimgunay
Mon Jul 19, 2021 9:20 pm
Forum: OpenSees.exe Users
Topic: Time History Analysis on 3D RC Frame: Convergence problem at only one column
Replies: 2
Views: 57

Re: Time History Analysis on 3D RC Frame: Convergence problem at only one column

You can try reducing the number of fibers, especially in the cover.
by selimgunay
Mon Jul 19, 2021 9:15 pm
Forum: OpenSees.exe Users
Topic: Issues on the Stiffness Matrix Extraction & Output
Replies: 6
Views: 505

Re: Issues on the Stiffness Matrix Extraction & Output

You can also use the printA command for the structure stiffness matrix.

https://opensees.berkeley.edu/wiki/inde ... tA_Command
by selimgunay
Mon Jul 05, 2021 4:28 pm
Forum: OpenSees.exe Users
Topic: How to release moment at the ends of a rigid link?
Replies: 7
Views: 216

Re: How to release moment at the ends of a rigid link?

Are you sure that it is not an unstable system when you have hinges at the member ends?
by selimgunay
Wed Jun 23, 2021 9:01 am
Forum: OpenSees.exe Users
Topic: How to model gear-pinion-rack system in OpenSees?
Replies: 2
Views: 186

Re: How to model gear-pinion-rack system in OpenSees?

There is no built-in command. You can try modeling it with translation and rotation springs.
by selimgunay
Fri Jun 18, 2021 11:55 am
Forum: OpenSees.exe Users
Topic: nonlinear time history analysis
Replies: 12
Views: 3881

Re: nonlinear time history analysis

If you want an identical analysis time step for all motions, you can use the smallest, which is 0.004 sec. But if there is no specific reason for running all with the same analysis step, you can run each with the corresponding ground motion step. What is the period of your structure?
by selimgunay
Fri Jun 18, 2021 11:52 am
Forum: OpenSees.exe Users
Topic: analyze failed
Replies: 2
Views: 266

Re: analyze failed

Can you run an eigenvalue analysis successfully?
by selimgunay
Mon Apr 12, 2021 5:20 pm
Forum: OpenSees.exe Users
Topic: Bridge Model with Truss and Beam-Column Elements OR End Moments Release
Replies: 8
Views: 1206

Re: Bridge Model with Truss and Beam-Column Elements OR End Moments Release

If you have distributed forces on the truss elements, that could be the problem.
by selimgunay
Mon Apr 12, 2021 5:17 pm
Forum: OpenSees.exe Users
Topic: My pushover analysis (2D Frame) is not converging.
Replies: 1
Views: 523

Re: My pushover analysis (2D Frame) is not converging.

Instead of the analyze $Nsteps command, you can try other nonlinear solution algorithms, convergence tests and tolerances to overcome the convergence problems. Below is an example of this type of adaptive solution algorithm for nonlinear dynamic analysis. You can adapt it for the nonlinear static (p...
by selimgunay
Mon Apr 12, 2021 5:07 pm
Forum: OpenSees.exe Users
Topic: Math Does Not Work On OpenSees Wiki
Replies: 1
Views: 461

Re: Math Does Not Work On OpenSees Wiki

Because of that issue, documentation is being transferred to GitHub:

https://opensees.github.io/OpenSeesDocumentation/
by selimgunay
Mon Apr 05, 2021 10:31 am
Forum: OpenSees.exe Users
Topic: Tangent Stiffness Proportional Damping on Updated Frequencies
Replies: 1
Views: 475

Re: Tangent Stiffness Proportional Damping on Updated Frequencies

To be able to use tangent stiffness proportional damping, you need to use $betaK or $betaKcomm, where $betaKcomm is preferred for numerical purposes and better convergence. Instead of computing $betaKcomm for each time step and instantaneous frequency, you can approximately compute it for an elongat...
by selimgunay
Sun Apr 04, 2021 9:28 pm
Forum: OpenSees.exe Users
Topic: Joint2D
Replies: 2
Views: 570

Re: Joint2D

You can use it for RC as it was developed as a result of a study that focused on RC structures:

Arash Altoontash, 2004, "Simulation and damage models for performance assessment of reinforced concrete beam-column joints", PhD Dissertation, Stanford University, California, USA.