Search found 108 matches

by EricsonEncinaZ
Mon Apr 08, 2019 1:09 am
Forum: OpenSees.exe Users
Topic: ZeroLengthSection Element for cantilever
Replies: 3
Views: 3716

Re: ZeroLengthSection Element for cantilever

The code you posted looks well to me, everything is consistent: node definition, fix conditions, GT, section definitions and orientations. Probably not causing your problem but, within a fibre {...} block you have "set" commands, May this make OpenSees confused? Different topic: Given the base units...
by EricsonEncinaZ
Mon Apr 08, 2019 12:39 am
Forum: OpenSees.exe Users
Topic: Why are additional nodes resulting in failure + convergence
Replies: 8
Views: 6758

Re: Why are additional nodes resulting in failure + converge

You may be having localisation issues: Coleman&Spacone 2001 "Localization Issues in Force-Based Frames Elements". Despite you use FBE you have to ensure you have enough IPs to actually capture an objective response of the element non-linearity. Remember that this is a distributed plasticity element,...
by EricsonEncinaZ
Wed Apr 03, 2019 3:11 am
Forum: OpenSees.exe Users
Topic: ZeroLengthSection Element for cantilever
Replies: 3
Views: 3716

Re: ZeroLengthSection Element for cantilever

It would be good to have more details about the elastic element and the fibre sections you are using for your ZLS elements, like materials, section discretisation, orientation vector of the ZLS element, etc. With the information you provided I may dare to say that the displacement or the load impose...
by EricsonEncinaZ
Fri Mar 29, 2019 12:07 am
Forum: OpenSees.exe Users
Topic: Convergence issue on Linux version of OpenSEES
Replies: 1
Views: 2227

Re: Convergence issue on Linux version of OpenSEES

I have had similar issues with different version of OpenSEES running in both Windows and Linux machines and HPC facilities. So, I may doubt whether it is completely because of the OS or it is because of the different versions and revisions of OpenSEES. For example, the current version for Windows is...
by EricsonEncinaZ
Thu Mar 28, 2019 11:54 pm
Forum: OpenSees.exe Users
Topic: Timoshenko beam
Replies: 5
Views: 4923

Re: Timoshenko beam

If elastic, you can calculate the properties by hand and assigned them to the elastic element, as you are currently doing.
You can also try a fibre-based section, and then assign that section to a beam-column element.
by EricsonEncinaZ
Thu Mar 28, 2019 11:52 pm
Forum: OpenSees.exe Users
Topic: Eigen analysis problem
Replies: 4
Views: 4447

Re: Eigen analysis problem

Mass in OpenSees should be given in units of force·time²/distance, like kN·s²/m. For example, if the base units of your model is kN and m and you want to define 1000kg then in order to be consistent with your base units you should define that mass as 1 kN·s²/m. You can also create your own set of un...
by EricsonEncinaZ
Thu Mar 28, 2019 2:30 am
Forum: OpenSees.exe Users
Topic: Timoshenko beam
Replies: 5
Views: 4923

Re: Timoshenko beam

I would say elements have their own local reference system, so you can define things like Iy and Iz. As a separate case, the domain has its own reference system. Now both RS do not know each other, so you have to let them know how to interact, this is done by the vector vecXZ and the geometric trans...
by EricsonEncinaZ
Thu Mar 28, 2019 2:21 am
Forum: OpenSees.exe Users
Topic: Eigen analysis problem
Replies: 4
Views: 4447

Re: Eigen analysis problem

Are you sure that the same vecXZ vector passed in the geometrical transformation fits all the directions of the elements you defined?
You are saying tha all the elements are defined with the local z axis pointing in the global Y axis.
Also check units, mass and stiffnes definitions.
by EricsonEncinaZ
Thu Mar 28, 2019 2:12 am
Forum: OpenSees.exe Users
Topic: BARSLIP Material
Replies: 1
Views: 2359

Re: BARSLIP Material

In OpenSees you have to be consistent with the basic units you are working on. If your basic units are: force in N, length in m and time in seconds, for example, then all the stresses should be given in N/m² = Pa, moments in N·m, kg in N·s²/m, ... etc. It is important to note that some materials are...
by EricsonEncinaZ
Thu Mar 28, 2019 2:03 am
Forum: OpenSees.exe Users
Topic: Timoshenko beam
Replies: 5
Views: 4923

Re: Timoshenko beam

According to the commands you are using you have a 3D domain, so the vector passed in the geometrical transformation tells the domain how your element is oriented, i.e. the relationship between the element's local reference system and the global reference system. If you do not provide the vector in ...
by EricsonEncinaZ
Thu Mar 07, 2019 10:37 pm
Forum: OpenSees.exe Users
Topic: Conversion moment-rotation to moment-curvature.
Replies: 2
Views: 2638

Re: Conversion moment-rotation to moment-curvature.

Curvature = Rotation / Lp, where Lp is the length over which the rotation occurs. This assumes the rotation is constant over Lp.
You can read any of the many publications in the equivalent plastic hinge length for columns, walls and beams to have a better idea :-D
by EricsonEncinaZ
Wed Feb 27, 2019 11:59 pm
Forum: OpenSees.exe Users
Topic: [eleResponse $ele integrationPoints]
Replies: 2
Views: 2814

Re: [eleResponse $ele integrationPoints]

Hehehe better to get them from the source code and put them into a procedure. Below the proc in case it is useful proc infoIntegracion {inte NoIPs WorP} { # Check info is correct if {$inte!="Lobatto" && $inte!="Legendre" && $inte!="Radau" && $inte!="NewtonCotes"} { return "infoIntegracion: The integ...
by EricsonEncinaZ
Mon Feb 25, 2019 3:02 am
Forum: OpenSees.exe Users
Topic: moment curvature
Replies: 3
Views: 3620

Re: moment curvature

Hi, You can track the moment and curvature directly into the integration point that you are interested in. - recorder element -xml secDsp.out -time -ele $ele -section $sec displacements - recorder element -xml secFrc.out -time -ele $ele -section $sec forces If you are recording a zeroLengthSection e...
by EricsonEncinaZ
Sat Feb 23, 2019 1:45 am
Forum: OpenSees.exe Users
Topic: [eleResponse $ele integrationPoints]
Replies: 2
Views: 2814

Re: [eleResponse $ele integrationPoints]

A workaround is to define a 2D domain, 2 nodes, 1 elastic section, 1 FBE/DBE element with the require IPs, save the position and weights of the IPs in variables, wipe the 2D model and then start the 3D model as normal, all in the same script execution. The "wipe" command will delete the 2D model, bu...
by EricsonEncinaZ
Thu Feb 21, 2019 2:26 am
Forum: OpenSees.exe Users
Topic: connectivity of bond slip in a cantilever
Replies: 5
Views: 4862

Re: connectivity of bond slip in a cantilever

Working now, it gives 0.249 seconds :-D, I do not know if it is ok, I just made it run. What I did to your code was: 1. changed the builder to "model BasicBuilder -ndm 2 -ndf 3" 2. Based on the node coordinates I assumed [3] -- zero length -- [1] -- FBE -- [2], so I changed your code accordingly 3. ...