Week 3 - 2D meshing for sheet metal

Aim: To create mid-surface for the Hood model & perform preprocessing for the component & Generate Proper Mesh Flow adhering to Quality criteria & minimum Trias

PROCEDURE

1. Import the CAD model in ANSA (i.e model.stp)
2. Check the Geometrical Errors

Checks>Geometry>Geometry-visible> (check box single cons & sharp edges)>Execute

Total 51 errors encountered in Geometry consisting Unchecked faces & Needle face

3. Right Click on any Error & select Show or Show only for the individual error to be shown on screen

Once All Errors are resolved Check Geometry Again & Ensure there are no Errors left in Geometry.

4. Inspect no. of component in the model using

Lists>Properties

5. Now Proceed to midsuface Generation

Define Material for the Geometry as Default MAT1 Material & close

6. Select the Individual component from the Properties list

7. Check thickness of the part at different cross-sections and store the value

8. Since the component is found symmetric, to reduce meshing time delete half part using faces>Rm.dbl

9. To Create a Mid-surface

Select Faces>Midsurface>Skin>select entire faces visble>select side to offset >enter the thickness to be assigned to midsurface & midplane is generated

Check geometry again

Checks>Geometry>uncheck Single cons >Execute> fix errors, if any

10. Enter Quality Criteria for the Geometry

Utilities>quality Criteria or for shortcut Press F11

Select Required Criteria & enter the values as shown & enter Apply

11. Utilities>Mesh Parameters & enter target Length, Minimum & Max Length as required

12.Now in Mesh Module set the shell element length as 5 for optimum results

Select Perimeters >Length>5 & middle click

13. Check whether all holes have even no. of hot points and defeature areas where quality criteria would fail

Check for every Hole

14.Check the perimeter for average length of 5 mm & clean Perimeter using

Hot points> delete & Perimeter>init

15.Now Proceeding with meshing

Mesh generation>Best mesh>select and continue with meshing smaller areas for better result

16.Remove possible trias pointing towards hole using

Shell mesh> Reconstruct /Smooth

17. Complete meshing for the Geometry

Use Shell mesh> reconstruct to alter the mesh to obtain minimum trias

Use Shell Mesh>smooth to smoothen the mesh flow

Check the mesh for any failed criteria and clear if any

18. Repeat the Procedure for the remaining Components as shown & save the model

Conclusion:

We conclude the Hood model is completely meshed with minimum Trias Possible, quality criteria are met & ready for Processing.