I have a relatively simple model with 3 solid bodies and have been running simulations to try and get consistent results. I started off with a very coarse mesh and to ensure the solver managed to converge.

I have gradually reduced the mesh size in there areas of interest (pull connections and locations of applied restraint) and have ran into a number of problems. The maximum stress values continually rise the more I refine the mesh due to singularities and the stress error plots return extremely high values. I have used a number of techniques provided throughout the forum (not shown in this model), such as fillets, simplification of geometry with little success.

So my questions are:

- What mesh size should I be using at the areas of interest and the areas deemed not critical
- What stress error is acceptable
- What techniques are best to eliminate singularities

Thanks in advance.

Mike

HI Mike,

I did not download your model so these are just general remarks. The best way to deal with singularities in my humble opinion is to do a non-linear analysis and let the equilibrium iterations deal with them but you may not have the NL option. Try and turn on large displacement in the study properties - it will do the same thing but you won't have a plasticity model so they might still be high. Sim NL with plasticity and contact is not the most robust of combinations for getting a result to converge.

Assuming your areas of interest are not where the singularities are then just make sure the stress in those areas has leveled off as you reduce the mesh. You can plot the error there but they should be ok once the stress converges.

Also you don't really want your areas of interest near a restraint as they are idealized and typically overly stiff in some respect but this is not always the case for a well chosen restraint system.