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Model Overconstraints

Submitted by gprinz on

Hello all,

I have created a 3-d dynamic model in ABAQUS using shell elements.  When I run the analysis I get several warning messages indicating that I have zero pivot nodes.  When I locate where these nodes are, I find that they are in the middle of my beam (modeled with shell elements) away from any boundary conditions.  Does anyone know why ABAQUS is indicating these inconsistent overconstraints in the middle of my model???  The analysis fails to converge when NLGEOM=yes but has no problems converging when NLGEOM is removed.

Thanks in advance

-Gary S Prinz

Never Mind, the problem is solved, I had specified too small of a mass in my material definitions.  This caused numerical singularities and some nodes, which is another meaning of the "zero pivot" warning.

Mon, 10/27/2008 - 19:47 Permalink