Solver problem. Zero pivot when processing D.O.F. 1 of 1 nodes. The nodes have been identified in no 1

[Sakthiiitm]

Hi all
I am getting this error when I give MPC tie/beam/link between two parallel plates could anyone please tell me the reason and how to rectify it.
Solver problem. Zero pivot when processing D.O.F. 1 of 1 nodes. The nodes have been identified in node set WarnNodeSolvProbZeroPiv_1_1_1_3_3.

Solver problem. Zero pivot when processing D.O.F. 2 of 2 nodes. The nodes have been identified in node set WarnNodeSolvProbZeroPiv_2_1_1_3_3.

What should we do if we have connect to parallel plates without bolts? Only MPC tie/beam/link between two plates notes in the contact is enough or we have give some other constraint also?
I was stuck with this for long.
Thanks in advance

 

[FEA way]

It depends on what this connection represents but it’s very likely that mesh-independent fasteners will be the best way to go in your case. Unless it has to be pure point-to-point connection - then rigid body constraints can help you attach the reference points to the plates.

 

[Sakthiiitm]

Even if I use fasteners I'm getting errors.
Using thr fasteners interaction alone is fine or do we have to add anyother interaction also?

I have a doubt why can't i use MPC tie for a point in master plate and set of nodes in slave surface?

 

[FEA way]

To define mesh-independent fasteners you can create attachment points first, then add a fastener between them, specify a connector section or select the rigid MPC option and define the radius of influence. But MPC constraint should also work if you select the points properly. You could e.g. use a partition to force a node to be located where you need the connection.

 

[Sakthiiitm]

Thank you
I am using abaqus command window inp file by coding
Could you please help me on this
I'm want a joint to be lap joint so i have connected the nodes which lies within the joint that is i have used MPC beam to set of coressponding nodes in both the plate which are in contact in the joint
I have connected all the nodes in the joint region and the force that cause the joint to shear is applied.
when i do this it throws an error of zero pivot or negative eigen value. How to rectify this?

 

[FEA way]

Can you share the file ? It's hard to say what's wrong without seeing the model.