- Creating the base results output database file
The output database file that you choose to be the base results becomes the starting point for the combined results output database file.
- Choosing between the initial and the final design cycle
You can specify that the base results be taken from the output database file generated by the initial design cycle or from the output database file generated by the final design cycle. In most cases you will select the initial design cycle and view the progression of the optimization from the initial design cycle to the final design cycle; for example, to follow the change in stiffness. Select the final design cycle if you performed a frequency optimization and want to view the frequency and the mode shape of the first few modes. If you performed a shape optimization, you should take the base results from the output database file generated by the first design cycle.
- Choosing the original model
The Optimization module modifies the material definitions and the section assignments before running the initial design cycle of the optimization process. The original model is the model that existed before any modifications were made by the Optimization module.
You can specify that the base results be taken from the output database file generated by the original model. However, the optimization process does not run an Abaqus analysis of the original model. Therefore, you must run the analysis manually before you can choose the original model as the base results. (The Abaqus input file for the original model is stored, along with all the input files generated by the optimization process, in the optimization process name\SAVE.inp directory. The name of the input file for the original model is optimization process name_org.inp.)
The output database file that you use for the base results must be generated without parts and assemblies, as described in Writing input files without parts and assemblies. The input files generated by the Optimization module do not include parts and assemblies, regardless of any user settings in Abaqus/CAE. However, if you create the base results from an input file that was not generated by the Optimization module or by executing a job from Abaqus/CAE, you must ensure that the resulting output database file does not contain parts and assemblies.
- Appending to the base results
After you have specified the output database file that will be used as the source of the base results, Abaqus/CAE appends the optimization results and the Abaqus analysis results to the combined output database file.
- Appending the optimization results
Abaqus/CAE appends the optimization variables as field data to the combined output database file after every design cycle, and each design cycle appears as a frame in the combined output database file. Similarly, Abaqus/CAE appends the optimization values as history data to the combined output database file.
- Appending the analysis results
You can do the following to specify which analysis results data are written to the combined results output database file:
Specify from which design cycles the analysis results should be written.
Specify from which models the analysis results should be written. Abaqus/CAE creates a combined results output database file for each model in your optimization process.
Specify for a selected model from which steps within the model the analysis results should be written.
Specify which analysis field variables should be written.
History data are not written to the combined database file during the combine process. The combined output database file contains only the history data from the base results output database file.
It is recommended that you save the analysis results after the initial and final design cycle when you create the optimization process. After the optimization is complete, you can select the output database file generated during the initial design cycle as the base results. You can then combine the base results output database file with the optimization results from every design cycle along with the analysis results from the final design cycle, as illustrated in Table 1.
Table 1. Saving optimization and analysis results in the combined output database file.
| |
Design Cycle |
|---|
| Initial |
First |
Second |
Third |
Fourth (Final) |
|---|
| Data saved |
Analysis results (field and history data) |
Optimization results |
Optimization results |
Optimization results |
Optimization results and analysis results (field data only) |
| Action |
Create base results |
Append to base results |
Append to base results |
Append to base results |
Append to base results |
For example, if you executed a topology optimization, you can then do the following:
View the initial state of your model; for example, the initial geometry and the loads and boundary conditions.
View the change in the optimization variables—normalized material distribution variable (MAT_PROP_NORMALIZED)—during each design cycle to observe the progression of the optimization.
View the final state of your model; for example, the optimized geometry and the displacements and the stresses and strains.
Create a history plot that tracks the change in the objective and constraints.
You can apply similar conditions to view the beginning and ending state and the progression of the shape and sizing optimizations.
Combining optimization results is supported only for optimizations that you configured with the following analysis cases:
Simple analysis (a single model, a single step, and a single load case)
Frequency or modal analysis
Linear perturbation analysis with multiple load cases
Optimization with multiple models