The dynamic analysis did not converge for all steps in the analysis. In this section, you should debug to find out where in your model the issues arise.

First, you can see which steps that has not converged by opening the <analysis_name>conv.txt-file. This file is found in the same folder you exported the analysis to. If you named the analysis dynamic_ you should look for a file named dynamic_02conv.txt. An excerpt is shown below.

For the steps that has not converged it will state CONVERGENCE NOT ACHIEVED AT 500 ITERATIONS AT LOADSTEP X. From this file we see that 2 of the total 5 initial steps has not converged. In addition, the analysis has some difficulties in the dynamic steps.

We need to find out where in the model the problems arise in order to, in the next step, point out where possible adjustments in the model or analysis set-up can be done. Go back to your analysis in AquaView. The convergence norm can be plotted and displayed for the entire analysis. Select Results > Convergence norm. Start the playback of the analysis and see how the colour changes with the degree of convergence issues. We see that the beam has some difficulties in achieving convergence. The same applies for the lower most element of Rope 1. If you select this element, you can get the convergence plot for the analysis. This is illustrated in the figure below.

Now that we have identified the problem, we can look into possibilities to resolve the convergence issues.