HyperMesh 文档3

Refi i g T g Achie e a Q a i Me h - HM-2030
In this tutorial, you will learn how to:
Mesh the part to determine poor element quality
Suppress small edges
Split surfaces
Remove interior fixed points
Replace closely placed fixed points
Create final mesh
Topological details of the geometry may affect the quality of the mesh created from the surfaces. Some of these details may not reflect any major feature of the part s shape, and can be removed without concern. When modifying the topology affects the shape of the surfaces, a compromise must be made between the part shape and the element quality necessary for the analysis. Other times, adding topological features that do not change the shape of the part may actually help create a better quality mesh.
E e ci e: Refi i g T g Achie e a Q a i Me h
S e 1: O e he de fi e, c l i p_ e f i n e.h m.
The model for this exercise is c l i p_ e f i n e.h m. Take a few moments to observe the model using the different visual options available in HyperMesh (rotation, zooming, etc.).
S e 2: C ea e a e i i a e h.
1.Access the a e h panel by doing one of thefollowing:
From the Menu Bar, select Me h, then C ea e, then 2D A Me h
From the main menu, select the 2D page, then click a e h
2.Set the selector type to f .
3.Go to the i e a d bia sub-panel.
4.In the e e e i e = field, type 2.
5.
5.For e h e:, select i ed.
6.Switch the meshing mode from i e ac i e to a a ic.
7.Select f >>di a ed.
8.Click e h to mesh the surfaces.
Initial mesh on the defeatured clip model
S e 3: Re ie he e h a i .
1.Take a minute to rotate, zoom, and pan the model to review the mesh that was created. Note the locations
where the mesh was not created in rows and columns of quads.
2.Access the Chec E e e panel by doing one of the following:
From the Menu Bar, select Me h, then Chec , then E e e , then Chec E e e
From the main menu, access the T page, and then click chec e e
3.Go to the 2-d sub-panel.
4.In the e g h field, type 1.
5.Click the e g h button to evaluate the minimum length.
6.Note the elements that failed the check. The topology will be edited to correct of some of these, and the
others will be left as is.
7.Click e to return to the main menu.
e the M de b e to turn off the display of the elements in the 10 component.
S e 4: Re e h edge b c bi i g fi ed i .
1.Access the i edi panel by doing one of the following:.
From the Menu Bar, select Ge e , then Edi , then P i
From the main menu, select the Ge page, and then click i edi
2.Go to the e ace sub-panel.
3.Verify that the active selector is set to ed i .
4.Select the lower fixed point as indicated in the following image.
5.Once the point is selected, activate the e ai ed i button.
6.Select the upper fixed point as indicated in the following image.
7.Once the second point is selected, click e ace.
Selecting fixed points to be combined
S e 5: Re e he fi ed i i e i a face .
1.You should still be in the P i panel.
2.Go to the e sub-panel and choose at cursor option.
3.Select the four fixed points as shown in the following image.
Each fixed point will be deleted as you select it.
These fixed points are left over from a defeaturing operation where small holes were removed. They could remain without greatly sacrificing the element quality, given the element size used for the mesh.
Fixed points to be removed
4.Click e to go to the main menu.
S e 6: Add edge he face c he e h a e .
1.Access the face edi panel by doing one of the following:
From the Menu Bar, select Ge e , then Edi , then S face
From the main menu, select the Ge page, then select face edi
2.Go to the i i h de sub-panel.
3.Under de a edge, set the active selector to de.
4.Zoom into the area indicated below and select the indicated fixed point.
5.With the active selector now on i e , select the line shown in the following image.
Once both the point and line are selected, an edge will be created from the location of the fixed point perpendicular to the line.
Select fixed point and line to split the surface.
6.Repeat sub-steps 6.3, 6.4, and 6.5 for the following point and line.
Select fixed point and line to split the surface.
7.Repeat sub-steps 6.3, 6.4, and 6.5 for the following point and line.
Select fixed point and line to split the surface.
8.Repeat sub-steps 6.3, 6.4, and 6.5 for the following point and line.
Select fixed point and line to split the surface
S e 7: Add edge he face c he e h a e .
1.Go to the i i h f / a e sub-panel.
2.In the i h a e column, set the active selector to f .
3.Select the surfaces indicated in the following image.
Surfaces to be selected for splitting
4.If necessary, toggle the direction selector to N1, N2, a d N3. Click N1 to make the selector active.
5.Press and hold your left mouse button, and then move it over the edge indicated in the following figure.
Once over the line, the cursor will change to a square with a dot in the center, . Release your mouse button. Click two points anywhere along the edge. Do not click a third.
Nodes will be placed on the line for N1 and N2.
6.Press F4 on the keyboard to enter the di a ce panel.
7.Go to the h ee de sub-panel.
8.As in 7.6, press and hold your left mouse button, and then move it over the edge of the hole, as indicated in
the following image. Once over the line, the cursor will change to a square with a dot in the center. Release your mouse button.
Select fixed point and line to split the surface
9.Click three points anywhere along the edge.
Temporary nodes will be placed on the line representing N1, N2, and N3.
Note that the technique used to create nodes to select where none existed before can be used in any place where nodes need to be selected but don t exist in the model. You can create nodes in this manner on lines, surfaces and elements. For more details, see the HyperMesh online help. Pick the index and type, P i c k i n g N o d e on Ge e or E e e .
10.Click ci c e ce e to create a node at the center of the hole.
11.Click e to go to the face edi panel.
12.Click B to make it the active selector.
13.Select the node that was just created at the center of the hole.
14.Click i .
15.Click e to go to the main menu.
The surfaces are trimmed through the center of the hole.
S e 8: S e ha ed edge ca i g a a edge.
1.Go to the edge edi panel.
2.Go to the ( ) e sub-panel.
3.Select each of the lines in the image below using your left mouse button and click e .
Each line will become suppressed (blue) as you click suppress.
Surface edges to suppress by toggling
S e 9: Re e h he a .
Remesh the surfaces of the part, using the automatic mode, a size of 2.5, and the mixed mesh type.
e the M de b e to display the elements in the 10 component.
2.Access the a e h panel.
3.Verify that e e i e = is set to 2.5 and the e h e is set to i ed.
4.Select f >> di a ed to select all displayed surfaces.
5.Click e h.
S e 10: Re ie he e h a i .
1.Take a minute to rotate, zoom, and pan the model to review the mesh that was created. Note that the mesh
now consists completely of rows and columns of quads.
2.Enter the Chec E e e panel.
3.Go to the 2-d sub-panel
4.In the e g h field, type 1.
5.Click the e g h button to evaluate the minimum length.
Note the elements that failed the check. There are only two elements that fail the check, and these fail the check because of the shape of the part. However, they are not too small compared to the global element size, so you can leave them as they are.
6.Access the a e h panel.
7.Go to the QI i i e sub-panel.
8.Verify that e e i e = is set to 2.5 and the mesh type is set to i ed.
9.Click edi c i e ia.
10.In the Ta ge e e e i e field, type 2.500.
11.Click A and OK.
12.Select f >> di a ed to select all displayed surfaces.
13.Click e h.
Note that the old mesh is replaced by the new mesh.
14.If there is a message saying, "There is a conflict between the user requested element si e and qualit criteria
ideal element si e," click the button, Rec e a i c i e ia using size of 2.5.
15.Access the a i i de panel by doing one of the following:
From the Menu Bar, select Me h, then Chec , then E e e , then Q a i I de
From the main menu, select the 2D page, then select a i i de
16.Go to g1 and verify that the c . QI is 0.01.
This low value indicates that the mesh is good quality. The higher the number, the lower the mesh quality.
S e 11 (O i a ): Sa e .
The part is now meshed and ready to be set up for an analysis. Save the model, if desired.
Go to HyperMesh Tutorials。