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Hi Larisa,

The FRCM strips need to be embedded to the entire surface to simulate the bond, otherwise, you cannot transfer the tensile forces to the masonry wall.
I attach the modified file here:
This is the damage: Lately we have implemented the crack width, it is very useful: You just have to add to the recorder material.cw

Bare in mind that it works with the new stko version and you need to update also opensees

Maybe you can reduce the number of steps to 300/400, try it and see when the number of steps does not affect anymore the results.

Regards

Thank you very much for the fast response.

The model is doing exactly what I wanted. Just to be clear, the truss embedded in the solid has to be meshed with the solid so they can work together, is that correct?

In addition, I'm also trying to model a bidirectional mesh in the TRM and I was thinking of doing a mesh with vertical truss and horizontal trusses (both embedded in the solid otherwise I get an error of singularity). Both configurations (vertical/horizontal) work nicely separately, but the overlayer (this is the vertical trusses + horizontal trusses) provides the same results as the first layer I applied. So, Does it make sense to do it this way? Should I do the embedding some other way to consider the two layers in the behaviour?

Thank you again!!

attached you will find the results with both strips that is equal to the results you presented in the previous comment followed by the results with the horizontal strips only.

Dear Larisa,

The truss elements represent the frcm strips which are bonded to the surface, thus they need to be entirely bonded to the solid to ensure to transfer the tensile forces of the reinforcement to the masonry wall.

As you know, the horizontal strips increase the flexural capacity and the horizontal the shear capacity. Therefore, if the unreinforced wall fails in shear, adding vertical strips shouldn't increase the shear capacity.

If you are modeling a bidirectional net you should always model both directions as you did. With your assumption the only simplification you make is to assume that the mortar used has zero in-plane shear strength.

Looking at the damage pattern you posted I see that the vertical strips increased the flexural capacity since I don't see horizontal cracks at the base of the panel. The panel fails in shear. In addition, the strut in compression appears to be larger.

The panel with only the horizontal strips starts failing in flexure and then in shear, it is a mixed mode failure.

Did you compare the load displacement curve? Could you show it? Did you do any analytical calculations?

Enjoy your weekend.

Lucy