I am new to ABAQUS Standard. I am doing Coupled pore fluid-displacement analysis in ABAQUS. The solution is diverging with the error "P.PRESS. CORRECTION TOO LARGE COMPARED TO P.PRESS. INCREMENT". I know that I can relax the solution correction via Controls command but I wish to know, why does ABAQUS need such a condition (correction < 1% of increment) for convergence. How will it affect my final solution if I play with the solution correction ? I would highly apreciate any help. Thanking you in advance.
Abaqus uses this because in a newton method, a small residuum alone does not guarantee that you are close to the solution. Therefore, an additional check on the last correction is done. Simple example, solve x^30=0 with a newton method; residuals will become small very quickly, even while you are still far away from the solution and each increments still changes the solution.
I strongly warn against changing this - use solver controls (number of iterations, number of allowed attempts etc.) to improve convergence; changing the precision may give you a completely wrong solution.
- Badges
- Science topic