Choose Material for TRM modelling

[admin]

Dear Larisa,

I asked Massimo for some insight. Modeling a sudden drop like that it's quite complicated, and also not so realistic. This type of curve is obtained experimentally due to the localization of damage. But in reality, some fracture energy is always needed to create a fracture.

You can try using DamageTC1D and calibrate the parameter according to your behaviour to obtain something like this:

1.png (81.23 KiB) Viewed 4061 times

Let us know how it goes.

Francesca

[Larisa GR]

Thank you very much Francesca!

I will try it now and let you know how it goes!

[marafini.f]

Great, sorry I erased your post by accident, please report your model if you need further assistance

[Larisa GR]

Hello Francesca,

I followed your advice and create a DamageTC1D (it runs in the material tester) but I keep getting the error that "NDMaterial not found.."
Could it be related with the type of element I'm using to model the BTRM (a 4 point face with quad elements)?

[marafini.f]

Hi Larisa,

Yes, you are right. You are trying to apply a uniaxial material to a 2D element that will not work.

You can create a PlateRebar property, one for each direction in which your fibers work, and insert it/them into a LayeredShell (you need at least three layers, with a thickness that sums up to the thickness of your reinforcement).

Like this you will construct a "2D material" from the uniaxial one, without accounting for shear, as I guess you can assume your reinforcement has not shear strength.

Then substitute the quad element you used with out ASDShellQ4 and it should work.

Be careful with the mesh element dimension and the fracture energy you put in the DamageTC1D, with the autoregularization and the mesh size you assigned it could be too low. Just check and in case you can change either Gt or create smaller elements. You can always use parallel computing.

Best,
Francesca

[Larisa GR]

Hello Francesca,

You can create a PlateRebar property, one for each direction in which your fibers work, and insert it/them into a LayeredShell (you need at least three layers, with a thickness that sums up to the thickness of your reinforcement).

Like this you will construct a "2D material" from the uniaxial one, without accounting for shear, as I guess you can assume your reinforcement has not shear strength.

Then substitute the quad element you used with out ASDShellQ4 and it should work.

I did what you suggested and I was able to generate the material and run the analysis with out getting any error related to the material. However, I haven't managed to converge the vertical analysis (as I mentioned before it is a shear compression test with two steps first vertical analysis and then horizontal analysis).

So I think that I have a problem on the base model. I tried to run the model of the URM wall with the vertical loading and it doesn't converge and I cannot find the error (file MACRO_URM).

Find attached both scd file (URM and With the TRM reinfrocement)

Any suggestion on what I'm doing wrong?

Thanks you

[marafini.f]

Dear Larisa,

I did not catch it before, but you had used a 2d physical property for a 3d element. You don't need to put the damageTC3D inside the PlaneStress property.
You can assign it as it is.

Plus you have fixed the top face, and nothing was moving.

We set up your model in a way that you can run it in parallel.

Try setting up this one first and then add the reinforcement.

Best,
Francesca

[Larisa GR]

I did not realised I left my 2D material!
Thanks you!

I will work this one and then move again to the reinforcement.

[marafini.f]

You are welcome!

[Larisa GR]

Hello Francesca,

I managed to run my URM model without any inconvenience! Thank you very much!
So now I added my layers of TRM. I did what you told me some post before Plate rebar + LayerShell and I have an error that I cannot figure out.

I don't know if the problem is the embedded element (I followed the instruction of the webinar of massimo) or that I'm missing sth. I tried to run one of the models of the webinar, the reinforced column and I get a similar error. Do you think I missing something installed in my computer that is needed in order to run the analysis (the simple pull out example with which massimo explains the element runs perfectly)?? It is weird because it looks like a convergence error. But I'm using the same configurations that the analysis before applying the TRM layers.

Any suggestions?

Thank you in advance!