You can use the restart capability to continue the analysis from the middle of a completed step or from the middle of a partially completed step. The restarted analysis uses a new step that continues the analysis from a specified increment of the previous step. This section describes an example of this usage.
Assume that you have done the following:
Created a model called Model-A that has two ABAQUS/Standard analysis steps, Step-1 and Step-2.
Used the Edit Restart Requests dialog box in the Step module to output the restart information every 10 increments.
Created a job called Job-A that uses Model-A.
Analyzed the model.
You suspected that the loading is too severe for the structure and might lead to instabilities or collapse of the structure and, hence, to numerical convergence difficulties. As a result, you used the Step module to save the restart information every 10 increments of each step. When you ran the analysis, you found that the analysis terminated before the end of Step-2, at increment 25. You used the Visualization module to look at the results of the analysis and realized that the negative eigenvalue messages confirmed your suspicion that the structure might have become unstable. Now that you have some idea of the collapse load level, you want to restart the analysis at increment 20 of Step-2 with lower levels of loading and more frequent output of results data. The following steps describe a recommended procedure to follow:
Copy Model-A to a new model, say Model-A-restart, and make Model-A-restart the current model.
Add the new Step-3 to Model-A-restart.
Modify the load levels and output requests in Step-3. For example, if the load at Step-2, increment 25 was 260 and the load at Step-2, increment 20 was 250, you might change the load level for the end of Step-3 to 262. In addition, you can increase the frequency at which data are written to the output database so that you can follow the progression of the collapse of the structure. You can also reduce the size of the maximum increment to control the resolution of the data that are generated by the analysis. For more information, see “Restarting an analysis,” Section 9.1.1 of the ABAQUS Analysis User's Manual.
From the main menu bar, select Model
Edit AttributesModel-A-restart. From the Edit Model Attributes dialog box that appears, do the following:
Toggle on Read data from job and enter Job-A to indicate the job from which the restart data will be read.
Set the restart location:
Enter Step-2 to indicate the step from which the restart data will be read.
Choose Restart from increment/interval, and enter 20 to indicate the increment from which the restart data will be read.
Choose and terminate the step at this point to indicate that Step-2 should terminate at increment 20. Step-3 will continue the analysis from this location.
Copy Job-A to a new job, say Job-A-restart, that uses Model-A-restart. ABAQUS/CAE sets the job type to Restart.
Submit Job-A-restart for analysis.