sps210
Computer
- Oct 2, 2011
- 5
I have two orphan meshes in inp format: a) first is a beam-like geometry (n1 nodes, m1 elements), and b) second is a surface mesh of a nearly-cylindrical geometry (n2 nodes, m2 element). I want to find the final node position upon application of certain loads such that the beam-like geometry rests on the nearly-cylindrical rigid body. I have merged the two meshes by appending the two files making sure that node and element numbers do not coincide between the two meshes. The beam and cylinder have intersections in space, but they should not interact in the first step. They are unconnected meshes.
I wish to use CAE for further analysis.
I am trying to model problem in two steps. In the first step, I apply force on the beam so that the beam moves away from the cylinder. The boundary conditions are set to prevent three non-collinear nodes from moving due to the application of the force. In the second step, I let go of the force and set up interation between the surface mesh and volume mesh so that the beam does not go through the cylinder. Here, the surface mesh has similar boundary conditions (three non-collinear nodes do not move). The boundary conditions are active for all steps.
When I trying the running the model without the cylindrical surface mesh, everything is fine. But when I try to run just the first step (I have disabled second step) with both the cylindrical surface mesh and beam volume mesh, here are the errors I get for the first step:
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There are 2 unconnected regions in the model.
Solver problem. Zero pivot when processing D.O.F. 1 of 2 nodes. The nodes have been identified in node set WarnNodeSolvProbZeroPiv_1_1_1_1_1.
Solver problem. Zero pivot when processing D.O.F. 2 of 23 nodes. The nodes have been identified in node set WarnNodeSolvProbZeroPiv_2_1_1_1_1.
Solver problem. Zero pivot when processing D.O.F. 3 of 24 nodes. The nodes have been identified in node set WarnNodeSolvProbZeroPiv_3_1_1_1_1.
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The solver does not converge in 5 attempts. It works fine for just the beam geometry, but when I simply add the cylindrican geometry (and ignore it for the first step), it has a problem converging. Any tip are appreciated.
I wish to use CAE for further analysis.
I am trying to model problem in two steps. In the first step, I apply force on the beam so that the beam moves away from the cylinder. The boundary conditions are set to prevent three non-collinear nodes from moving due to the application of the force. In the second step, I let go of the force and set up interation between the surface mesh and volume mesh so that the beam does not go through the cylinder. Here, the surface mesh has similar boundary conditions (three non-collinear nodes do not move). The boundary conditions are active for all steps.
When I trying the running the model without the cylindrical surface mesh, everything is fine. But when I try to run just the first step (I have disabled second step) with both the cylindrical surface mesh and beam volume mesh, here are the errors I get for the first step:
---------------
There are 2 unconnected regions in the model.
Solver problem. Zero pivot when processing D.O.F. 1 of 2 nodes. The nodes have been identified in node set WarnNodeSolvProbZeroPiv_1_1_1_1_1.
Solver problem. Zero pivot when processing D.O.F. 2 of 23 nodes. The nodes have been identified in node set WarnNodeSolvProbZeroPiv_2_1_1_1_1.
Solver problem. Zero pivot when processing D.O.F. 3 of 24 nodes. The nodes have been identified in node set WarnNodeSolvProbZeroPiv_3_1_1_1_1.
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The solver does not converge in 5 attempts. It works fine for just the beam geometry, but when I simply add the cylindrican geometry (and ignore it for the first step), it has a problem converging. Any tip are appreciated.