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Direct Femap Interface to ADINA — Structural Analysis Example

The ADINA User Interface (AUI) program offers comprehensive pre- and post-processing capabilities for the complete suite of ADINA Solution programs – Structures, Thermal, CFD, Electromagnetics and Multiphysics. However, other third-party pre- and post-processors can also work with the ADINA solvers and may offer certain advantages. For example, Femap contains interfaces to certain CAD packages not currently supported by the AUI, such as interfaces to ACIS, CATIA and Pro/ENGINEER (now called Creo Elements/Pro).

With the direct Femap interface to ADINA, users can benefit from their familiarity with Femap and leverage the advantages of Femap in pre- and post-processing with the powerful features of the ADINA solvers. In this Brief, we demonstrate the direct Femap interface to ADINA for a propeller model that involves glueing (which allows different meshes for the glued components), contact and a preload bolt in static analysis followed by a frequency analysis.

Figure 1 shows the geometry of the assembly of the propeller model with five components. The bottom of the shaft is fixed and centrifugal loading is applied to the whole model. In addition, pressure load is applied to the three blades.



Figure 1  Schematic of propeller model


As shown in Figure 2, the first glue region is between the blade and blade root and the second one is between the blade root and outer surface of the hub. Two contact regions are also defined between the bottom of the cap and the top of the hub as well as the top of the shaft and the bottom of the hub. In addition, a bolt element (not shown in Figure 2) is employed to connect the cap and the shaft with a preload.




Figure 2  Locations of contact and glue regions


We demonstrate the ease of using the direct Femap interface to ADINA with the following step-by-step analysis.

Step 1: Import the geometry model into Femap and clean it up

Step 2: Define the material properties and mesh with 3D solid elements




Step 3: Create bolt element and rigid elements that connect the cap and hub to the bolt element




Step 4: Apply bolt preload, body load of rotational velocity in global X direction and pressure load on the three blades




Step 5: Apply constraints at the bottom of the shaft and fix the rotation DOFs of the bolt element

Step 6: Define the glueing property with default values. Create the glue regions and the corresponding connectors of glueing




Step 7: Define the contact property with "Friction Param 1=0.2". Create contact regions and the corresponding connectors of contact




Step 8: Perform the nonlinear static analysis using the direct Femap interface to ADINA

Enter the Job Name and Heading (if desired) in the ADINA Analyze window, select options as shown, and run ADINA to solve the model.




Step 9: Define settings for frequency/modes analysis

Set "Number of Frequency/Mode Shapes" equal to 10.




Step 10: Define settings for restart analysis (to calculate frequencies)

Check "Restart Previous Analysis" and select "Propeller_a.res" as the file in the field "Restart Data from".




Step 11: Perform frequency analysis using the direct Femap interface to ADINA

Note that the analysis is performed in the deformed configuration corresponding to all loads and contact conditions.

Enter the Job Name and Heading (if desired) in the ADINA Analyze window, select options as shown, and run ADINA to solve the model.




Step 12: Load the results through the Femap neutral file

Enter the Femap Neutral File name to load the results for post-processing.




Figures 3 and 4 show results obtained from the above two analyses, visualized in Femap. The results of the frequency analysis are also shown in the movie above.




Figure 3  Band plot of von Mises stress




Figure 4  First mode shape with band plot of total translation


Finally, users who are familiar with the AUI can also load the results into the AUI for post-processing since it provides some additional features that are not available in Femap. For example, the AUI allows the user to plot error indicators as a guide for determining the accuracy of the solution and where the mesh should be refined.

The entire analysis, from pre-processing to post-processing, is performed within the Femap environment using the direct Femap interface to ADINA. Users already familiar with Femap can adapt easily to analyses using ADINA, and thereby have access to more analysis options within Femap.

We recognize that the ADINA CAD/CAE interfaces are important and also Femap with ADINA CFD and FSI provides a powerful analysis tool.


Keywords:
Femap, Nastran, pre-processor, post-processor, glueing, contact, frequencies, bolt element, CAD, CAE

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