Zero pivot when processing D.O.F. 1

[psantunes]

Hello!

I'm doing a standard contact simulation divided in two steps, beetween a 3D discret rigid surface and a deformable hyperelastic 3D model. The first step corresponds to the approach and in the second step I Input a vertical force and no boundary conditions for the discrete surface. The analysis is running with no errors but abaqus gives the following warning "Solver problem. Zero pivot when processing D.O.F. 2 of 1 nodes". I read in the Abaqus manual that this kind of warnings may happen when the two surfaces meet for the start of the contact. Can anyone give me a help in this subject

Many thanks!

 

[corus]

If you've made contact in the first step with fixed displacements then you should get no zero pivots then. In the 2nd step remove those redundant restraints and apply your load. If you've only one load in one direction then the other freedoms must be restrained or else you'll get rigid body motion.

corus