FEMAP TUTORIAL Composites Laminate · 2018. 11. 20. · In NX Nastran, the laminate is defined by the PCOMP card which calls the material and defines the ply pattern. In FEMAP you

FEMAP TUTORIAL

Composites Laminate

Femap 11.1

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ATA Engineering FEMAP 11.1

Composites Laminate Tutorial in Femap

Content subject to change without notice. © 2018 ATA Engineering, Inc. Femap is a trademark of Siemens PLM Software, Inc.

Overview

This document provides a written description of a demonstration of Femap composite laminate capabilities. The model will be made from a simple generic wing geometry file. This tutorial also covers a useful API implementation for composites and the PostProcessing toolbox Freebody tool.

Software:Femap 11.1

Input Files Required:wing_section.stp wing_laminate_data.xls

Output Files Created:Wing_compositeDemo.modfem

This tutorial is part of a series of free Siemens PLM Software training resources provided by ATA. For more tutorials, whitepapers, videos, and macros, visit ATA’s PLM Software website: http://www.ata-plmsoftware.com/resources.

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Content subject to change without notice. © 2018 ATA Engineering, Inc. Femap is a trademark of Siemens PLM Software, Inc.

Concepts• Importing and cleaning up geometry

• Preparing geometry for meshing

• Meshing with quad elements and using mesh controls to adjust the mesh

• Creating orthotropic materials and laminates properties

• Applying constraints and pressure loads

• Analyzing and post-processing the model

• Use the Freebody tool in the PostProcessing toolbox



1 Content subject to change without notice. © 2018 ATA Engineering, Inc. Femap is a trademark of Siemens PLM Software, Inc.

ContentsTutorial 21. Introduction 2

1.1. Input Files Required 21.2. Output Files Created 21.3. Testing Update 2

2. Import and Simplify Geometry 32.1. Import the geometry into Femap and Simplify 3




Tutorial

1. IntroductionThis document provides written description of a demonstration in Femap. The model is a simple generic wing model.

1.1. Input Files RequiredThe following files will be provided:wing_section.stp Laminate_Data_20141106.xls

1.2. Output Files CreatedThe following files will be created during this demonstration:Wing_compositeDemo.modfem

Figure 1-1: ▶ Example Femap Demonstration Model.




2. Import and Simplify Geometry

The step file geometry will be imported into Femap and then it will be prepared for meshing.

2.1. Import the geometry into Femap

1. File → New.

2. File → Import → Geometry.

3. Navigate to wing_section.stp and select.

4. Set the Title to wing_section.

5. Set the Geometry Scale Factor to 1. Uncheck Increment Layer and check Increment Color. Increment Layer imports each part in the assembly into separate layers. Increment Color sets the outlines of each different part to be different colors. Click OK.

6. If you cannot see the wing, turn the geometry ON with the View Geometry Toggle in the Entity Display toolbar.

2.2. Use the Model Info tree to display the base bracket

In the Model Info pane, expand Geometry. The geometry containing the wing is all untitled after import. Select the transparent highlighter tool from the Model Info commands. Select any of the untitled bodies to see them highlighted.

Figure 2-1: ▶Import the geometry.




3. Mesh Geometry3.1. Apply an initial meshMeshing this geometry can be done with a few simple clicks but to get a good mapped mesh it is a bit more complex. First select Mesh → Geometry → Surface and select all four surfaces. Leave all the defaults as-is, including a blank Property field. Select OK when asked to mesh with Plot-Only Elements.

The initial mesh on the four surfaces is shown in Figure 3-2 and it is clearly not a nice mapped mesh. It can be seen that the four surfaces are not actually connected. FEMAP currently does not know that these surfaces should be meshed together.

Figure 2-2: ▶One of the four bodies.

Figure 3-1: ▶ Automesh surface dialog box.




Use Ctrl-Z to undo the mesh. Next select Geometry → Surface → NonManifold Add and select all of the surfaces. Select a Non-Manifold Add Tolerance of 0.01 with Incremental Checking selected and hit OK. When the operation is complete Femap will highlight the free edges, and you can see that the internal spar to wing surface intersections are not highlighted in Figure 3-3.

Figure 3-2: ▶Initial Mesh attempt for the four surfaces of the wing model.

Figure 3-3: ▶Free edges after NonManifold Add command.




Redo the mesh surfaces operation. Note that when you select all surfaces there are now eight surfaces which were created by the intersection of the spars to the wing surfaces. The new mesh with the surfaces all connected correctly is shown in Figure 3-4.

3.2. Improve the mesh with the Meshing ToolboxThis mesh is still not ideal. The Meshing Toolbox provides a lot of flexibility to fix the mesh. Select the pane. If it is not there, select the

Meshing Toolbox toggle from the Panes toolbar to turn it on.

1. Select the Mesh Surface section of the toolbox.

2. Select Mapped Mesh.

3. A mapped mesh a geometrically regular finite element mesh which can be created with triangular or quadrilateral element. In this case leave the element shape as four node quad elements and leave the Auto Mapped Approach ON.

4. Make sure the Auto Remesh is ON .

5. Turn ON the Select tool .

6. Pick one of the surfaces and click and watch the mesh Auto Update.

Figure 3-4: ▶The new mesh after the NonManifold Add command so that the surfaces are all connected properly.




7. The surface in the center is now nicely mapped, but it is obvious the mesh sizing was not correct. Make sure the Mesh Size is set to 0.05.

8. Select the rest of the surfaces. TIP: if you are having trouble selecting the surfaces, right-click on the view window and select Pick Front as your selection method.

This mesh looks much better, but notice that some of the mesh spacing is not consistent.

9. Switch to the Combine/Composite Curves Pane in the Meshing Toolbox.

10. Select the Add Curves Action. Leave the Merge to Existing check ON. Select the edges highlighted in Figure 3-7.

Figure 3-5: ▶The mesh after one surface has been selected with the Mapped Meshing Surface Mesh via the Meshing Toolbox.

Figure 3-6: ▶The mesh after all surfaces have been selected with a mesh size of 0.05.




11. Select the additional curves highlighted on the left in Figure 3-8.

12. Select F6 to pull up the View Options. On the Labels, Entities, and Color pane select the Curve – Mesh Size option. Change Show As to Symbols and Count and select OK.

Figure 3-7: ▶The edge fixed with Combine/Composite Curves is highlighted in red on the left. The updated mesh is shown on the right.

Figure 3-8: ▶The other edges to be fixed with Combine/Composite Curves are highlighted in red on the left. The updated mesh is shown on the right.




13. Switch to the Mesh Sizing Pane in the Meshing Toolbox. Change the Operation to Set To and change the Number of Elements to 50 and select one of the long edges on the wing.

3.3. Create groups from surfacesNow that the mesh is regular, the next step is to create groups for applying the different laminate information.

1. Return to the Model Info Pane .

2. Create a group of ALL the elements by right clicking on Groups and selecting New. Set the title to ALL and click OK.

3. Select Group → Element → ID and pick Select All, then click OK.

4. Create a new group called Top Surf 1

5. Select Group → Element → On Surface and select one of the three surfaces on the top (+Y) side of the wing.

6. Right click on the check box to the left of the group Top Surf 1 and pick Show Selected Group Only. You should only see the elements on the surface you selected in step 5. Play with the toggles showing the group with ALL of the elements and hiding the new Top Surf 1 group.

Figure 3-9: ▶Mesh updated with 50 elements on the long edges.




7. Recreate the procedure from steps 4 and 5 seven more times from the other model surfaces. Create two more Top Surf groups, three Bottom Surf groups, and two Spar groups.

4. Assign materials and properties to the meshed FEM 4.1. Create an orthotropic material

Before making a layup or assigning properties, the materials need to be defined. You can manually assign the materials or you can import materials via bulk data file or a macro in excel. First we will assign one of the materials manually.

1. Open the excel file “Laminate_Data_20141106.xls” and open the “ply_materials” tab.

2. In FEMAP right click on Materials in the Model Info tree and select New.

3. Select the Type button and change the material type to Orthotropic (2D).

4. Using the data from the “T300/934 Carbon Epoxy” row of the Excel sheet fill in the information in FEMAP. The form is shown in Figure 4 1.

Figure 3-10: ▶Mesh updated with 50 elements on the long edges.




4.2. Create a laminate property

We will make a layup using the material we just created. In NX Nastran, the laminate is defined by the PCOMP card which calls the material and defines the ply pattern. In FEMAP you must define a Laminate property which points to a layup which then defines the materials and ply pattern. (When importing a deck from Nastran FEMAP automatically creates both the laminate properties and the layups.)

1. Right click on Properties in the Model Info Tree and create a new property.

2. Change its type to Laminate under Plane Elements.

3. Name this new property Test Laminate and select the Layup icon to create a layup.

4. Title the Layup Test Layup.

5. Select the material defined in the previous section, set the thickness to 0.00127 and the angle to 0 and select New Ply.

6. Repeat three times changing the angle to 45, -45, 90.

7. Highlight all of the four plies and hit Duplicate to copy them all.

Figure 4-1: ▶Example Material Entry for T300/934 Carbon Epoxy.




8. Select all eight plies and hit Symmetric to copy them symmetrically.

9. Select the first and last ply, change the thickness to 0.003 and hit Update Thickness.

Now that we have learned to create a laminate property we will instead import a set of predefined laminates stored in an Excel spreadsheet via an Excel macro.

Figure 4-2: ▶Element/Property Type dialogue.

Figure 4-3: ▶Layup editor dialogue.




4.3. Use Excel with an API to load all of the materials and layups

1. Undo all the way back to the creation of the new property.

2. Open the file “Laminate_Data_20141106.xls” in Excel and select Enable Content to allow the macros embedded in the file to run.

3. In Excel, select the Developer tab. Then select the Macros button (If you can’t find the Developer tab, right-click on the ribbon and select Customize the Ribbon… The Developer tab can be toggled on from this dialog box.).

4. Choose the macro titled “LoadPlyMaterialsFemap” and hit Run. Go into FEMAP and look at the Model Info tree specifically under the Materials section of the Model. There should be three new materials.

5. Go back to the Excel spreadsheet and run the macro “LoadAllPcompFemap.” There should be now be four Properties and four Layups in the Model Info tree.

4.4. Assign the laminates to the different zones

The next step is to apply the laminate properties to the different zones. There are many methods for doing this but in this case we will create groups and then apply the properties to the different zones.






1. First create the group names by right clicking on Groups in the Model Info tree and selecting New. Create four groups with this method and name them:

a. FP Upper Wing

b. FP Lower Wing

c. Rib 303

d. Rib 304

2. Go to Group → Operations → Automatic Add and select “Active” to allow group additions to the active group.

3. Double click on FP Upper Wing to activate this group. Make sure the surfaces are turned ON and everything is shown. Then go to Group → Element → on Surface and select the three top surfaces in the +Y direction and hit OK.

4. Right click on the toggle for FP Upper Wing to “Show Selected Groups Only” and see the elements for these surfaces are now in the group.

5. Return to showing the whole model and step through the same process for the other three groups.

a. For FP Lower Wing select the three surfaces on the bottom in the –Y direction.

b. For Rib 303 select the rib in the +X direction.

c. For Rib 304 select the rib in the –X direction.

6. Assign the elements the correct laminate properties by selecting Modify → Update Elements → Property ID. Then select the elements by group (one at a time) and hit OK. Select the corresponding Entity ID and hit OK. Repeat for all four groups.

Figure 4-6: ▶Top three surfaces selected for load application.




7. Using the View Style Drop Down menu change the “Color With” option to “Property Colors.”

8. Color by property to check the groupings. Go to Modify → Color → Property and choose Select All and then OK. On the Color Palette pane select Random. Then on the Color Assignment Pane select “Multiple Colors by ID” and hit OK.

9. The final step in preparing the element properties is to apply a material orientation. Go to Modify → Update Elements → Material Orientation. Select all and hit OK. In the Material Orientation Direction pane choose “Coordinate Axis” under “Material Angle” and select the X direction of the 0..Basic Rectangular coordinate system.

10. You can see the material orientation by hitting F6 to pull up the View Options control. Under the “Labels, Entities, and Color” Category select “Element – Material Direction”. Then check the box “Show Material Direction” and choose OK. Zoom in to see the vectors drawn on each element aligned with the X direction.

Figure 4-7: ▶Elements colored by property color.

Figure 4-8: ▶Element material direction shown on each element.




5. Apply Loads and ConstraintsNow that the model is complete the next step is to apply boundary conditions and loads.

5.1. Apply Constraints

1. Right click Constraints in the Model Info tree and select New. Name it “Fixed BC” and select OK.

2. Make sure nodes are showing. Right click on Constraint Definitions under the new boundary condition and select Nodal.

3. Rotate the model and select all of the nodes on both of the + and – Z ends.

4. In the Create Nodal Constraints/DOF pane select the Fixed button and select OK.

5. Turn on the View Constraints Toggle to view them.

5.2. Apply Loads

1. Right click Loads in the Model Info tree and select New. Name it “Pressure Load” and select OK.

2. Make sure surfaces are showing. Right click on Load Definitions under the new load and select On Surface.

3. Select the three top surfaces in the +Y direction.

4. In the Create Loads on Surfaces pane select Pressure. Leave the Direction as Normal to Element Face. Change the Pressure value to -10,000 and change the method to Constant.

5. Turn on the View Loads Toggle to view them.

6. Analysis6.1. Run Analysis

1. Right-click on the Analyses item in the Model Info Toolbox and select Manage. Click New. Name the Analysis Set Pressure Load and click OK.

2. Click Analyze. The analysis is finished when the date appears in the messages box.

3. Use the PostProcessing Toolbox to observe deformation and stress distribution. Use Tools → PostProcessing Toolbox to open the toolbox if it is not already open.

4. Expand the Deform option. Change the Style to Deformed. Change the Output vector to 1. Total Translation.

5. Turn off nodes and surfaces if needed.




6. Expand Scale under Options. Set Scale to Actual Deformations. Set Scale Actual By to 100.

7. Expand the Contour menu. Set the Style to Contour. Set the Output Vector to 1..Total Translation.

8. Turn off material directions via F6 if desired.

Figure 6-1: ▶Setting the Output Vector options for Deformation in the PostProcessing toolbox.

Figure 6-2: ▶Setting the Deformation scale.




9. Change the color of the Filled Edges under the category Tools and View Style in the View Option Dialogue (F6). Set the Color Mode to 1..Use View Color. Enter a View color of 0 (Black).

Figure 6-3: ▶Setting the Output Vector for contour.

Figure 6-4: ▶Change the border color of the elements to black.




7. Post ProcessingBeyond plotting deformation and individual ply stress results some more processing often needs to be done for composite analysis. These include enveloping across all of the plies and performing free-body cuts at important interfaces to look at load transfer.

7.1. Enveloping Results

1. Go to Model → Output → Process to bring up the Process Output Data dialogue.

2. Change “What to Process” to “One or More Selected Output Vectors”

3. Change the processing operations to “Envelope” and within this section change:

a. For max failure index leave it at “Max Value” for type (though this may change depending on what you are looking for be it a max or min.

b. Change “Envelope Approach” to “Envelope All Locations for Each Vector” which will give one result per element

c. Leave the Create Envelopes, Across Output Sets and Store Set/Location Info check boxes checked.

4. Set Store Output in Set to 0..New Output Set.

Figure 6-5: ▶The mesh after the applied deformation and contour.




5. Click Select the Output to Process

a. In the Select Output Sets to Process dialog box, select the output set (or sets) of interest

b. Uncheck the Output Vectors, All Output Vectors check box.

c. Make sure you set the “From Output Set” to your specific set so it points to the correct output vectors

d. Click the filter icon

e. In the Filter Output Vector dialog box, set Title Contains to “X Normal Stress*” and hit OK to get the failure index vectors for all plies

f. You can click the box with three check boxes to check all of these

vectors without having to click one by one.

g. Click OK to confirm your selection of the Output Vectors and to return to the Process Output Vectors dialog box

6. In the Process Output Data dialog box, note how the list of Operations That Will Be Processed field is filled with the list of selected Output Vectors

7. Click OK to create and populate the new Output Set called “Envelope All Locations” with enveloped data. This new set with have three vectors:

a. The max failure index

b. The max failure set location (in case you enveloped over multiple results sets)

c. The max failure ply location

Figure 7-1: ▶The Process Output Data dialogue box.




7.2. Free Body Tool

1. Create a new group called “Free Body Elements”.

2. Add elements via Group → Element → ID and select a single line of elements near the center of the wing.

3. Right click on the group and select “Add Related Entities”

4. Go to the PostProcessing Toolbox and expand the Freebody section.

5. Select the Freebody creation button next to the Freebody line of the Freebody Properties section . Name it Freebody and change the display to Interface Load and then select OK.

Figure 7-2: ▶Max envelope of X normal stress.

Figure 7-3: ▶New freebody dialogue.




6. Change the Output Set to “NX Nastran Case 1” from the Pressure Load. (Note: if you did not request nodal forces as an output in the original analysis, edit the analysis set (1. Pressure Load) and check Force Balance on the Nastran Output Requests dialog, then re-run the analysis.)

7. Select the Freebody Elements from the group and select the Freebody Nodes from one side of the elements.

8. When asked to sum the free body to the center of the nodes select Yes.

9. Note: To turn off the individual nodal vectors toggle the FX, FY, and FZ under Freebody → Nodal Vectors → Force Vector Display (Displayed Components) → Displayed Forces.

Figure 7-4: ▶Wing free body display.

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Tutorial1.Introduction1.1.Input Files Required1.2.Output Files Created1.3.Testing Update

2.Import and Simplify Geometry2.1.Import the geometry into Femap and Simplify

Button 1:

Documents

FEMAP TUTORIAL Composites Laminate · 2018. 11. 20. · In NX Nastran, the laminate is defined by the PCOMP card which calls the material and defines the ply pattern. In FEMAP you