How to get the pore pressure ratio?

michaelshu · Post by **michaelshu** » Fri May 01, 2009 7:26 pm

Hi,everybody!

I have a doubt about getting the pore pressure ratio.
The the pore pressure ratio is the ratio of the excess pore pressure and the initial vertical effective pressure.But as for the quadUP elements,the pore pressure is recorded in element nodes,and the stress is recorded in gauss points,which are different.How can I get the pore pressure ratio of a complex structure?

Many thanks!!!

kyonten · Post by **kyonten** » Mon Jun 15, 2009 9:15 pm

I don't think there is a command to get the nodal stresses in OpenSees. You could write a short script in Matlab or any programming language of your choice to compute nodal stresses from the gauss point stresses (stress smoothing approach). For a linear quad element with simple shape functions it is not difficult to do it.