mech-intro 14.0 ws04.1 meshing

7/31/2019 Mech-Intro 14.0 WS04.1 Meshing

1/16

2011 ANSYS, Inc. March 1, 20121 Release 14.0

14. 0 Release

Introduction to ANSYS

Mechanical

Workshop 4.1

Meshing Control


2/16


GoalsUse the various ANSYS Mechanical mesh controls to enhance the mesh for the

model below.

Problem statement:

The model consists of a CAD file representing a solenoid.

Our goal is to mesh the model using all defaults and inspect the result. Next we will add

mesh controls to modify the mesh in various regions of the model.


3/16


Assumptions

Since this is a meshing exercise we will not be applying loads or solving the model.

Instead we will assume a linear static structural analysis is to follow the meshingoperation.

Note, due to a certain randomness in the nature of meshing, the actual number ofelements generated during the workshop may vary from machine to machine. This

is normal.


4/16


UnitsOpen the Project page.

From the Units menu verify: Project units are set to US Customary (lbm, in, s, F, A, lbf, V).

Display Values in Project Units is checked (on).


5/16


Project Schematic1. In the Toolbox, double click Static

Structural to create a new analysis

system.

2. RMB on the Geometry cell and

Import Geometry. Browse to

Solenoid_Body.stp.

3. Double click the Model cell to start

the Mechanical application.

1.

2.

3.


6/16


Start by meshing the model using all defaults. This

will establish a base line from which we can

compare changes.

4. Highlight the mesh branch, RMB > Generate

Mesh.

Basic Meshing

4.

When mesh generationcompletes we can view themesh and inspect thestatistics in the details for the

mesh branch.

Note: node/element countmay vary slightly acrossmachines/platforms.


7/16 2011 ANSYS, Inc. March 1, 20127 Release 14.0

Basic Meshing

5. View the mesh metrics:

a. Highlight the mesh branch.

b. In the details under Statistics >

Mesh Metric specify Element

Quality.



Based on our inspection we may decide a more refined

mesh is necessary for our analysis.

6. In the mesh branch details expand the sizing

section and set the Relevance Center to

Medium.

7. RMB the mesh branch and Generate Mesh.

Mesh Size Control

The finer mesh is visuallyobvious. The details show anincrease in the number ofelements as expected.

5.

6.



Mesh Shape ControlA closer look at the mesh shows some anomalies where certain faces meet.

By zooming to the area in question we can see several small sliver surfaces areforcing a fine mesh locally.

Well attempt to clean this up using virtual topology.



8. Insert the virtual topology branch (highlight

the Model branch):

a. RMB > Insert > Virtual Topology.

Since it appears that the sliver area is closer to

being tangent to the sides, we will combine

these into virtual cells.

Virtual Topology

Side

Sliver

In order to preserve the basictopology we will join pairs of

surfaces into virtual cells ratherthan trying to combine all surfacestogether. The result will be 3 cellsper side, 6 in total.

a.


11/16


. . . Virtual Topology9. Create Virtual Cells:

a. Select one of the sliver surfaces.

b. Hold the CTRL key and select theadjacent surface (as shown at right).

c. RMB > Insert > Virtual Cell.

The resulting virtual cell is displayed in red.

Although underlying surfaces still exist,

this is the surface the mesher will use.

a.b.

c.


12/16


. . . Virtual TopologyContinue by creating the remaining 5 virtual

cells (select in pairs as before). When complete

you will have a total of 6 virtual faces and 4virtual edges.

10. Remesh the model (highlight the meshbranch):

a. RMB > Generate Mesh.

The resulting mesh shows

a much more uniformmesh with a significantreduction in elementcount.

a.


13/16


Mapped Face Meshing11. Map mesh several faces (highlight Mesh

branch):

a. Select the 3 planar faces shown here.

b. RMB > Insert > Mapped Face Meshing.

c. RMB > Generate Mesh.

As shown mapmeshing results iselements on theselected faces whichshare very regularshapes.

c.

b.

a.


14/16


Face Size Control12. Specify face sizing on selected face:

a. Select the face of the gusset section shownhere.

b. RMB > Insert > Sizing.

c. Set Element Size = 0.03.

d. Set Behavior = Hard.13. Remesh the model (highlight the mesh branch):

RMB > Generate Mesh.

a.

d.

c.

b.

13.


15/16


Edge Size Control14. Specify edge sizing on selected edges:

a. Select the 4 edges of the gusset shown here.

b. RMB > Insert > Sizing.

c. Change Type to Number of Divisions.

d. Set Number of Divisions = 25.

e. Set Behavior = Hard.15. Remesh the model (highlight the mesh branch):

RMB > Generate Mesh.

a.

b.

11.

d.

c.

e.


16/16


Edge Size ControlReview the mesh metric as compared to the original mesh. With just a few

refinements overall mesh quality has improved.

Original Mesh Metric

Final Mesh Metric

mech-intro 14.0 ws04.1 meshing

Documents