Week 3 - 2D meshing for sheet metal

2D MESHING FOR SHEET METAL

AIM:

To Generate the mid surface for all the components after checking the geometrical errors and mesh the mid surface with the given element Quality criteria.

GIVEN:

QUALITY CRITERIA

S.No	Quality Criteria	Value
1	Target/Average length	5
2	Minimum Length	2
3	Maximum Length	7
4	Aspect	3
5	Warpage	15
6	Skewness	45
7	Jacobian	0.7
8	Minimum Quad Angle	45
9	Maximum Quad Angle	135
10	Minimum Tria Angle	30
11	Maximum Tria Angle	120
10	Tria Percentage	15

CAD MODEL:

PROCEDURE:

STEP 1:

Import the given model file_open_Hood model_1.stp

STEP 2:

Check the geometry by selecting Tools_checks_geometry and clear the error

After checked and cleared the error by topocleanup, the component as been splitted into 5 model

To generate midsurface we have to find the thickness of the model

Go to Utilities_Measure and select the two points.

The splitted model and its thickness are shown below:

MODEL 1:

THICKNESS:- 0.75

MODEL 2:

THICKNESS:- 0.75

MODEL 3:

THICKNESS:- 1.2

MODEL 4:

THICKNESS:- 1.2

MODEL 5:

THICKNESS:- 1.2

MIDSURFACE:

For midsurface I choosed the manual method by offsetting the surface

Go to Modules buttons_Faces_Offset, select the one side face of the surface and enter the value of the thickness.

The final midsurface of each model are:

MIDSURFACE 1:

MIDSURFACE 2:

MIDSURFACE 3:

MIDSURFACE 4:

MIDSURFACE 5:

• Before mesh clean the geometry by topocleanup and cut option to get a better meshing
• Input the quality creteria value by pressing F11 and enter the given numbers.
• Enter the mesh parameter as per given target element length
• Go to modules_Mesh generations_Best and start meshing each surface

Meshed surface of each model and failure elements are shown below:

MESH SURFACE 1:

MESH SURFACE 2:

MESH SURFACE 3:

MESH SURFACE 4:

MESH SURFACE 5:

To clear the failure and to get proper mesh flow we can use the following methods:

• RECONSTRUCT on FEM.To apply this select Modules buttons_Shell mesh_Reconstruct
• SMOOTH on element.To apply this select Modules buttons_Shell mesh_smooth
• SPLIT AND SWAP on element.To apply this select Modules buttons_Elements_Split/Swap
• EDGE2PARAMETERS on macros.To apply this select Modules buttons_Macros_Edge2parameters
• Increase or decrease the node numbers.To apply this select Modules buttons_perimeters_Number/num+/-

COMPLETE MESH ON EACH MODEL:

To check the elements are passed OFF elements should be zero with the quality creteria

MODEL 1:

MODEL 2:

MODEL 3:

MODEL 4:

MODEL 5:

DRAW SHELL AS SOLID: After activating draw shell as solid the meshed shell elements will convert to solid,by considering the thickness assigned on PID

Go to Quality Creteria_presentation parameters_activate Draw shell as solid

BEFORE SELECTING DRAW SHELL AS SOLID:

AFTER SELECTING DRAW SHELL AS SOLID:

NOTE:Thickness has been updated on the element after activating draw shell as solid

LEARNING OUTCOMES:

At the end of this challenge I can able to:

• Perform geometry cleanup for any sheet metal component.
• Generate Midsurface manually without using automidsurface.
• Generate shell Mesh for any sheet metal component and knowledge of quality creteria.
• Identify quality failure and clear the failure and improve the mesh quality.

CONCLUSION:

Hence the geometrical error and mesh has been performed successfully.The thickness has to be generate after meshing.Quality failure are cleared and also got a proper mesh flow with low trias.