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Tension Only 3D

Posted: 11 Jun 2016, 10:38
by tiagofricardo111
Hi, I’m a student from Portugal and I’m doing a research for my thesis.
I’m trying to model a super simple structure that have:
- 4 Columns;
- 4 Beams;
- 2 SMA's (with 2 links);
- Dynamic analysis.
The problem is that I can´t put SMA’s cables working only in tension. I already did a structure more complex in 2D and it works perfectly.
Can you guys take a look and help me? I already search for the entire forum and I tried everything.

https://www.dropbox.com/s/xv41cbac50ap0 ... e.spf?dl=0

Thanks for your help.

Re: Tension Only 3D

Posted: 12 Jun 2016, 00:07
by tiagofricardo111
I already found out the mistake I was making. But I still have the same doubts. As I had mentioned, I'm trying to model a SMA cable 3D. There is some care in particular that has to get this modeling? Because in case of 2D is very simple. Is any difference in gap propertys when it changes to 3D?

I'm using your structure: Ch4-steel-01 and I'm trying to implement my bracing device. This device consists of two SMA's and four steel bars.
When I apply a horizontal displacement, the device behaves as expected. SMA work only with tension. But when I apply an earthquake, only in the X direction behavior has nothing to do with expectations.

It would be possible to look at my file? It's a little hard to explain the device. I'm working on this for weeks and I can not come up with anything ... You guys are my only hope, already searched everywhere and can not find absolutely nothing.

https://www.dropbox.com/s/33f2b5kd0awvo ... e.spf?dl=0

Re: Tension Only 3D

Posted: 22 Jun 2016, 14:50
by z.gronti
Dear tiagofricardo,

Please check your element connectivity. For example, i think that the truss elements Aco* and Aco*** should be connected to node n221* instead of n221.