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Cable nets roof

11 REPLIES 11
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Message 1 of 12
ioniovita
745 Views, 11 Replies

Cable nets roof

Hi to everyone,

I have some problems with my model. Can I send it to someone who can help me with this problems? Is about a cable nets roofs nets, who has some instability problems, who may be because of not declaring the right degree of freedom (because of having a cable nets and a steel tube section in the model).
I really appreciate any help.

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11 REPLIES 11
Message 2 of 12

Hi, from the screenshot I can't understand which are the cables and which are the steel tube and no release highlighted. How can we help you? Which instability you have? Which type of analysis you need to run???

More info please

Greetings

PasProStudio

www.pasquiniprogetti.eu

Structural + Detailing engineers
Message 3 of 12

Thanks for reply,
Firstly, I have isolated nodes that I can not delete them.... The secondly I have instability of type 2 for several nodes, which gives very large displacements, when I run static - nonlinear analysis (only from dead load).
In the image attached, is represented the cable nets and the rest are the steel tube sections.

cable.png

Message 4 of 12
ioniovita
in reply to: ioniovita

Can I use compatible nodes option, when I have a cable intersection? I have a large deformation of the structure (above 2.5 m in some nodes from dead load); no errors appears when I run the statin-nonlin PD analysis.

 

Message 5 of 12

If I don't see the model I can't give you a good suggestion. My opinion is that you made a wrong definition of cables, try to define it by dl=0 or assign them a pretension (for example 10 kN). Don't use the compatible nodes or any release...cable is an only tension element. I don't know if the geometry of your model is right or wrong, but try to use my suggestion.

Hope I help you, greetings

PasProStudio

www.pasquiniprogetti.eu

Structural + Detailing engineers
Message 6 of 12

I have tried different option... I have put additional towers to sustaint the structure and to have small deflaction, to abtain convergence results... but I have some problems with the model when I run the following analysis type:

- Seismic - P100-1/2006

- Spectral 

- Time history analysis

- Push over

I have attached the model, if can someone help me with this problems.

Thanks in advance

 

Message 7 of 12
ioniovita
in reply to: ioniovita

Sorry... the file was to big, I have attached a small one

Message 8 of 12

You may consider some changes in the scheme of the model e.g.

 

additional cables.PNG

 

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Artur Kosakowski
Message 9 of 12

Still have some problems with the model. Can it be because of the analysis type? The nodes are not declared correctly for the seismic analysis, maybe (error 905 in my case)? Have you succeeded with the analysis? Maybe I have missed something

Message 10 of 12

For a cable model you should have the assembly case with no. 1.

 

If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.



Artur Kosakowski
Message 11 of 12

Thank you for your work and advice. Is there any explanation of this? And can be performed a push over analysis for a given accelerogram (Vrancea for example) in case of cable structures like my model?

Message 12 of 12

Thank you for your work and advice. Is there any explanation of this?

 

The limitation of internal architecture of the program.

 

And can be performed a push over analysis for a given accelerogram (Vrancea for example) in case of cable structures like my model?

 

Push over analysis for cable models is not supported.

 

If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.

 

 

 



Artur Kosakowski

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