Sometimes the results I get from Abaqus are not what I expect. Perhaps the analysis does not complete while I didn't think it would be very troublesome, or I do get results, but they don't make sense to me. Though this can be very frustrating, it can also be seen as an interesting puzzle (especially if it is somebody else's problem ;) ). For that reason, I'd like to share some results with you that did not make sense to me. Let's see whether you can figure out what went wrong!
Over 5 weeks in a 2 hour session each week, from the 20st of October till 17th of November, Simuleon will hold an Online Training with live broadcasting. The training is called "Obtaining a converged solution with Abaqus"".
This course provides a useful insight in the theoretic backgrond of how non-linear problems are solved. You will learn how to develop models that will converge. You will learn to identify modeling errors that cause models to experience convergence difficulties. After this training you will be able to recognize when a problem is too difficult or too ill-posed to be solved effectively.
Sometimes you may wish to simulate a process where various parts interact with one another. In such cases it is often impossible to rely on predefined loads and boundary conditions, since the exact points of contact are dependent on the solution. Including contact in your simulation can be a more realistic way to represent loadings.
Abaqus provides a wide range of mechanical models and numerical methods for contact. We will begin this month’s webinar with an overview of these capabilities, considering how to select the best options for a given problem. We will then move on to some challenging example problems and investigate how advanced features of Abaqus contact can help convergence and ensure you obtain realistic solutions.
Every engineer trying to solve non-linear finite element analyses has experienced it: convergence difficulties. In this blog I will give ideas for finding the cause of the convergence issues, as well as some common solutions in Abaqus FEA.
1) Check the job diagnostics.
Open the odb and select tools>job diagnostics. Job diagnostics gives all warnings and errors, as well as residual and contact information. One of the most useful features is the highlight selection in viewport check box.
In the warnings tab, the user can see the location of numerical singularities and zero pivots (if applicable), which may give an idea of what causes these warnings.