Hi,
I modeled a PLATE MAT foundation using plates, Option Y, and the subgrade module.
I am using various load cases including earthquake (Spectrum Load Case).
However I found a contradiction when looking at Base Pressure results, specifically
some nodes show Negative base pressure values, but when I look at the corresponding node displacements (Y) they show negative values,
in the same way the Node Reactions (Y) show negative values, so I do not understand why this is happening.
Notice that I am no using Y COMPRESSION option but just Y for the Mat Plate
I would like to know if there are some restrictions or specific issues when using Spectrum Load case along with
Mat Plate option Y and reaction modulus.
Also, any explantion of the difference between Node Reaction (direction Y) and Base Pressure will be much appreciated.
Many thanks for any help. I am stuck on this naive issue.
Best regards,