Building (SFEM)

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In the following, performing of SFEM analysis on the Building model will be described:

Performing SFEM Analysis using ANSYS

After defining the input, the connector is created by right-clicking on the connector icon in the tree view and selecting the "add connector" option. The connector to ANSYS is defined as follows for this example. Please note that the correct connector type should be chosen within the configuration of the connector.


BuildingTutorial1.jpg


Also, another important step within the definition of the connector is the creation of the injector. The definition of the identifiers (please note the format of the identifiers, shown in the small window on the right buttom corner) for the ANSYS model is shown in the screenshot below


BuildingTutorial2.jpg


Important Note: Although an extractor is not used within the SFEM analysis, it has to be defined within the connector for the completeness.


Once the connector is defined properly, a physical model has to be defined accordingly, which is depicted in the following screenshot. In order to create a physical model, go to the models section on the tree view in the GUI and right click on the "physical model" directory.Note that, upon the selection of the evaluator, the input parameter involved in the definition of the connector are added automatically to the model:


BuildingTutorial3.jpg

Performing SFEM Analysis using NASTRAN

The essential difference between using various FE solvers is only important at the connector stage, i.e. the input/output files would be different for each solver. However, the steps to be followed and the way that SFEM analysis is performed remains in principal same.


Buildingresults5.jpg


Definition of the injector within the NASTRAN connector. Again, one should pay attention to the format of the identifiers, since these are crucial for the successfull completion of the FE analysis. If this formatting is not set appropriately, the FE analysis might fail:


Buildingresults6.jpg


Similarly as before, once the connector is setup correctly, a physical model is created based on this connector. For this purpose, simply define a new model and by clicking on the plus icon in the evaluator section, add the NASTRAN connector defined above. Observe that all the input parameters defined within the connector appear automatically:


Buildingresults4.jpg


In order to start the SFEM analysis, right click on the physical model and select "Run Analysis" option. The following wizard will pop up:

BuildingTutorial8.jpg


Select the uncertainty quantification option and then SFEM option in the next screen. You should have reached now the SFEM wizard. In this window, all the SFEM related method/input options can eb set interactively using the GUI:


BuildingTutorial9.jpg


Once you select the necessary options and parameters in the SFEM wizard, you can proceed to setup the high performany computing options. First select the Oracle Grid Engine and wait until all the queues are retrieved from the system. Once this step is completed click on the Queue column in the Analysis selection menu and select the appropriate queue for the FE solver, i.e. Nastran queue for NASTRAN solver, etc. Click on finish to start the analysis.


BuildingTutorial10.jpg


Performing SFEM Analysis using ABAQUS

Additional inpur quantities are necessary to execute the SFEM analysis with Abqus. The nodes and DOFs of the boundary conditions must be indicated, as well as the line(s) identifying the loading step.

For this example, the constrained nodes and DOFs are:

Constrained Node DOF
1015 1
1015 2
1015 3
1032 1
1032 2
1032 3
1389 1
1389 2
1389 3
1406 1
1406 2
1406 3

The lines identifying the load step is

*BOUNDARY, OP=NEW
    1015, 1,3, 0.
    1032, 1,3, 0.
    1389, 1,3, 0.
    1406, 1,3, 0.
*CLOAD, OP=NEW
    3232, 1, 100.
    3245, 1, 100.
    3258, 1, 100.
    3271, 1, 100.
    3284, 1, 100.
    3297, 1, 100.

Each line has to be inserted manually, one by one, in the "Step Definition" box (by pressing the[+] button).

Results of the SFEM analysis

In order to visualize the results, simply go to the analysis section of the tree view in the GUI. By selecting the results directory, you can observe the generated results objects:


Buildingresults1.jpg


Double click on the Sfem Output object in order to visualize the contents in the editor window:


Buildingresults2.jpg


If you click on the on the table view, all the second order statistics calculated for the whole displacement vector will be listed in the table view window. Note that the Node - DOF correspondence is also provided here as well:


Buildingresults3.jpg


The estimated statistics of the response obtained using various methods are summarized in the following table:

Summary of Statistics obtained with Perturbation Method(Node 1016 - DOF 1)

Response

NASTRAN Model  Abaqus Model

Mean Value

0.0250 0.0275

CoV

0.10 0.10