Why does this model produce many small pivot warnings?


It would be more accurate to use the term "pivot ratio" than "pivot" because the values being reported are ratios of the smallest pivot to the largest pivot. The reason for small pivot ratios is typically that a very high stiffness exists in the model, such as a very short beam that has been given an arbitrarily-high material or section properties.

In your model, the output indicated that the maximum pivot was at node 2078 and I found several beams tied into this node with large section properties and an elastic modulus of 0.3e14 psi. If you reduce the stiffness of these beams several orders of magnitude they will still be relatively rigid and you won`t get the small pivot (ratio) messages.





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