problems with a simple model, and element zerolength

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Sergiomed
Posts: 2
Joined: Wed Sep 28, 2016 3:54 am
Location: Universidad Nacional de Colombia

problems with a simple model, and element zerolength

Post by Sergiomed » Wed Mar 08, 2017 12:30 pm

Hello everyone, and apologizes for my english, it is not my mother tongue :roll:

So, i am doing a 2 stories RC building 3D model (only with frames) to try to get the capacity curve of a building which is impacted by a tsunami wave (this to get the vulnerability curve). But i have some problems/issues because i am modeling within the structure the non structural elements (masonry) due to some researchers have included them as resistent systems within the main system (moment resisting frame). In general i am using element nonlinearBeamColumn with fibers sections for modeling beams and columns and element zeroLength to model walls (masonry) as a diagonal truss element in the structure (i tryied with element truss and element corotTruss, but the axial results, stress - strain, are not what i expected, I did a model with SAP2000 to clarified the results). So i keep using element zeroLength to model them inspite of OPENSEES always puts some warnings about the lenght of zerolenght objects, because they are longer than 4m (i want to know if those warnings affect the results and what is the solution to model these masonry walls?) :oops:

in addition, i have to model a element to identify the shear failure on columns (i know the solution is to using a zerolengh object to conect the colums)... but i dont know if i can define only 1 dof (2 in 3d models because of both shear stress) with this element and the others just define as fixed dof (i mean like a link MultiLinear Plastic element in SAP2000). In other hand how could i define a element (like a element zerolengh with 1 section) just working on 1 dof with a section and the others just let them free? :P

Thanks for the awsome help you could give! :3 And hoping you could understand me :|

Sergiomed
Posts: 2
Joined: Wed Sep 28, 2016 3:54 am
Location: Universidad Nacional de Colombia

Re: problems with a simple model, and element zerolength

Post by Sergiomed » Wed Mar 08, 2017 12:37 pm

If someone wants to check the model, just let me know and i will try to upload it (because of it has more than 600 lines of code), i mean if it is necessary because it is working with some files (from examples that i got from openseeswiki) :p

Michaelpeter
Posts: 6
Joined: Sat Mar 11, 2017 9:18 pm
Location: cairo university

Re: problems with a simple model, and element zerolength

Post by Michaelpeter » Mon Jun 26, 2017 7:46 am

please give me your email i want to contact with you
hope you best wishes

selimgunay
Posts: 913
Joined: Mon Sep 09, 2013 8:50 pm
Location: University of California, Berkeley

Re: problems with a simple model, and element zerolength

Post by selimgunay » Mon Jun 26, 2017 10:35 am

You can define a zerolength element only between two nodes that have excatly the same coordinates.

Your approach of defining the shear failure is correct.

Michaelpeter
Posts: 6
Joined: Sat Mar 11, 2017 9:18 pm
Location: cairo university

Re: problems with a simple model, and element zerolength

Post by Michaelpeter » Thu Jul 06, 2017 11:59 pm

please give me your email i want to contact with you
hope you best wishes

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