Modeling of Shear walls with Boundary Elements

[nader28143]

Dear All,

I am trying to model a shear wall with boundary elements. It is easy to do so using the reinforced concrete rectangular wall section. However, I find it is a bit restrictive for my particular application. In fact, my walls are reinforced masonry and the boundary elements sometimes have different material properties (e.g. higher compressive strength). I am trying to model the boundary elements as columns and connect them to the web. I tried all types of constraints, but unfortunately, none worked. I am testing the modeling with static time history analysis. The load is applied to the web. The results are showing that only the web is moving and the two columns are not. I would appreciate your reccomendations/ suggestions.

Best Regards,
Nader Aly

[seismosoft]

Have you tried to divide the elements along the height of the wall and connect the intermediate nodes with rigid links?

Seismosoft Support

[nader28143]

Thanks for the reply.
Yes, I did divide the wall over the height into several segments. Then, I tried using rigid links/ rigid diaphragm or Equal DOF joint constraints to join the columns to the walls over the height. When I run the analysis it seems that there is no any effect from those constraints (each element is responding separately).

Best regards,
Nader Aly

[z.gronti]

Dear nader28143,

We generally use the rigid links to connect the requested elements.
Could you please check the assigned restrained type in your model with the rigid links? I think that you should restrain all the degrees of freedom, i.e. you should assign Restraint Type x+y+z+rx+ry+rz .

[nader28143]

Dear Zoi,

Many thanks for the reply.

This is exactly what I did. However, I still clearly see that the three elements (two boundary elements and the web) are not acting together. Maybe there is something wrong with the way the software understands the definition of the rigid link in this particular case. Please find the model I am using to verify this case in the link below:

https://www.dropbox.com/s/xp5yddz3imh2k ... E.spf?dl=0

In this model, I have applied the force intentionally at the BE. Once I run the model with real-time drawing of deformed shape, I clearly see the BE responding as if it is not attached at all to the web. Please let me know if there is a way to fix this issue.

Thanks,
Nader Aly

[z.gronti]

Dear nader28143,

If you assign the program default values in the Penalty Functions Exponents, available in the Project Settings>Constraints tab, the model will work properly. The low values you have assigned for the penalty functions exponents prevent the rigid link from working properly.

[nader28143]

Many Thanks Zoi. It works perfectly now. I really appreciate it.

Kindest Regards,
Nader