Catia-Finite Elements: Tensile of a Centrally Drilled Specimen

Simulation
1

Hi everyone,

I really need your help with a problem in finite element structure calculation under Catai V5.

I am trying to model the deformations of a steel specimen, drilled in the center and blocked by 2 jaws at the ends which must pull it from 6000N in 2 opposite directions. 

For each of the four surface areas in contact with the bits, I block all degrees of freedom except in the direction of the pull. 

And I impose a force distribution of 6000 N on each of them, paying attention to the direction of traction. 

But when I start the calculation, catia returns the error below: 

Was I wrong on one point? Fasteners for example? 

Thank you for your enlightenment

2

Hello

An image could shed light on the shape and location of the contact surfaces with the jaws...

A possible explanation: reading your message, I understand that the 4 surfaces leave your specimen free to move in translation in the direction of traction (displacement of solid, unsure balance).
Even when exerting two opposing forces of 6000 N, the mesh and the calculation introduce small variations of these forces, which does not ensure equilibrium.

At least one end of the specimen must be completely immobilized, and the tensile force (or imposed displacement) must be applied to the other end.

M. blt