How to Introduce dummy nodes when investigating SSI?

bayram_aygun · Post by **bayram_aygun** » Sun Sep 23, 2007 12:00 pm

My soil-pile model is basically made of one pile and two layers of soil strata.
I created a 2DOF Mesh for soil and 3DOF Mesh for nonlinear pile. Then I used
"equalDOF" to connect pile to soil mesh. Since I use nonlinear p-y springs to
model SSI, my zerolength elements have two nodes: one in the 2DOF soil and the
other one 3DOF pile. The problem is OpenSees puts an error sign stating:
"element zerolength has two nodes which are differing in DOF". I probably have
to introduce some dummy nodes but I don't know how. Is there any way that you
can help me?

Gang Wang · Post by **Gang Wang** » Mon Oct 15, 2007 7:16 pm

I saw you already had a good answer in mind: use two 2D nodes for then zeroLength, then equalDOF the 1st and 2nd DOF of one of the 2D node to the 3D node of your pile.