I'm trying to design a mat foundation. When I run the calcs I'm getting this warning as in the pic above. Does anyone know if this is concerning? The deflections are around 0.78" for D+L load case.
I am also having receiving this warning message. I modeled and analyzed one mat foundation by importing through RAM SS, where I did not receive this warning message. As I am now analyzing a second mat foundation from this same model, I am receiving this warning. The mat foundations have area springs set up, and have very similar vertical and lateral deflections between the two concept models.
Did you check the lateral deflection, and if so how much is it? Surely your 2 models are different in several ways; the shape of the mat, the magnitude of the lateral load, etc.
Thanks for the quick response Seth. Lateral deflections for the model with the warning message are 0.00106" and 0.00152" for the x and y directions, respectively. The lateral deflections for the other mat foundation model without the warning are 0.00219" and -0.00305" for x and y directions, respectively.
I varied the area springs KFr and KFs values from 0.1 to 0.15 and the warning went away. Is it possible that this warning is indicating the mat foundation is sliding?
Yes, exactly. I don't know exactly what the threshold is for large displacement warnings, but it's pretty small (maybe as a percentage of the model size).