Computing with Adaptivity

This task shows how to compute with adaptivity.

Adaptivity management consists of setting global adaptivity specifications and computing adaptive solutions.

• The Adaptivity functionalities are only available with a static analysis solution (without multi loads) or a combined solution that references a static analysis solution (without multi loads).
• To compute with adaptivity, you need to update the solutions.
• A global adaptivity and optionally a local adaptivity must have been defined.
• The former adaptivity specifications (created before V5R12) can be edited but they can not be computed with adaptivity.
  If you modify these specifications and launch a computation with adaptivity, a warning message informs you that these specifications will not be taken into account. You have to create new adaptivity specifications.

Open the sample07_2.CATAnalysis document from the samples directory.
In this particular example, a global adaptivity and a local adaptivity have been already defined.

• You can compute the static solution.
  To know more, refer to Computing Static Solutions.

1. Activate the Estimated local error image to visualize the quality elements.

   To do this, right-click the Estimated local error image in the specification tree and select the Activate/Deactivate contextual menu.

2. Double-click the Global Adaptivity.1 object in the specification tree to visualize the current error.

   The Global Adaptivity appears. Click Cancel to close the Global Adaptivity dialog box.

3. Double-click the Local Adaptivity.1 object in the specification tree.

   The Local Adaptivity appears. Click Cancel to close the Local Adaptivity dialog box.

4. Click Compute with Adaptivity in the Compute toolbar.

   The Adaptivity Process Parameters dialog box appears. Name: gives you the name of the adaptivity set you want to compute. Iterations Number: lets you specify the maximum number of iterations you want to perform to reach the objective error you have defined. Allow unrefinement: lets you choose to allow refinement or not. If you allow unrefinement, the global sizes of the mesh parts may be modified. Deactivate global sags: lets you choose to ignore the global sags. Existing global sags will be deactivated. Minimum size: lets you specify a minimum mesh size. The objective size must be superior to the mesh size. Sensor stop criteria: lets you specify a sensor. If you select this check box, the Parameter Convergence frame appears: Sensor parameter: lets you select the sensors. Multi-selection of sensor criteria is available. Tolerance (%): lets you specify the tolerance value.

   To sum up, the adaptivity process stops as soon as: the maximum number of iterations is reached or all objective errors are reached or all sensors selected as criteria converge.

5. Clear the Minimum size check box.

6. Select the Sensor stop criteria check box in the Adaptivity Process Parameters dialog box.

7. Activate the Sensor parameter field, select a sensor and enter a Tolerance value (in %).

   In this particular example, select the Energy sensor as shown below:
   	You can add other sensor criteria, delete a sensor criteria or delete all the sensor criteria. To do this, right-click a line and select the desired contextual menu: Add, Delete or Delete All. Only the sensors selected as stop criteria in the adaptive process are updated during the computation with adaptivity.

8. Click OK in the Adaptivity Process Parameters dialog box.

   The Computation Status dialog box appears. At the end of the computation, a Warnings message appears to inform you that the selected sensor has not converged and the objective error is not reached.

9. Click OK in the Warnings message.

   Note that a Local Mesh Size Map.1 object has been created under OCTREE Tetrahedron Mesh.1 in the specification tree and that the Adaptivities.1 set is now valid.

10. Activate the Estimated local error image to visualize the quality elements.

    To do this, right-click the Estimated local error image in the specification tree and select the Activate/Deactivate contextual menu.

11. Double-click the Global Adaptivity.1 object in the specification tree to visualize the current error value.

    The Global Adaptivity dialog box appears. Note that: after the first iteration of computation with adaptivity, the objective error you have specified (9%) is not reached.

12. Click OK in the Global Adaptivity dialog box.

13. Click Compute with Adaptivity .

    The Adaptivity Process Parameters dialog box appears.

14. Enter 2 as Iterations Number value and click OK in the Adaptivity Process.

15. Double-click the Global Adaptivity.1 object in the specification tree to visualize the current error value.

    The Global Adaptivity dialog box appears. The objective global error you have specified is reached.

16. Double-click the Local Adaptivity.1 object in the specification tree.

    The Local Adaptivity appears. The objective local error you have specified is reached.

17. Activate the Estimated local error image to visualize the quality elements.