diagonal test masonry

[francesco.alagna02]

Hello STKO team,

I am writing to you because for the past couple of weeks I have been trying to model a diagonal compression test on a masonry panel. Specifically, I am dealing with masonry reinforced with FRCM material.

My problem is that I am unable to relate the reinforcement layer to the substrate. From the model I have attached, it seems that the reinforcement does not cooperate with the model, as if it does not contribute.

[kesavapraba]

Hi, you idealized the connection between the FRCM and masonry as intact, which is not physically correct at all over the specimen. Why do assign equalDOF interaction if the interaction is intact? Instead, you can simply merge FRCM and masonry geometries and assign them with their repsective material properties.

[STKO Team]

Why are you saying it does not contribute? I see stresses on the strengthening layer.
If you mean it does not increase the overall strength, you have to make sure that all the parameters are set up correctly.

[francesco.alagna02]

Thank you for your response stko teams. Through testing, I noticed that the reinforcement indeed contributes to the panel. Additionally, I would like to understand if there is a way to define an interface other than perfect adhesion, such as by inserting sliding stiffness or maximum shear stress, in order to calibrate a potential detachment of the reinforcement from the support.

[STKO Team]

You can do that by replacing the equalDOF (on the interaction between the wall and the strengthening layer) with a zeroLength element.
This zeroLength will have nonlinear materials (stress vs displacement) according to the bond properties. Then in the zeroLength element you can specify the "distributed" options so that STKO converts those stress-disp curves into force-disp curves by using the tributary area