MESHING OF HOOD OF CAR USING HYPERMESH

AIM: CREATE A MESH AND CLEAR ALL QUALITY ERROR'S FOR THE GIVEN MODEL

PROCEDURE:

• Import file to hyperwork
• Delete solid surfaces
• Geometry cleanup
• Midsurface extraction
• Delete symmetry surfaces
• Defeaturing
• Assign quality criteria
• Meshing
• Quality error's cleanup

IMPORT STEP FILE TO HYPERMESH

Import the STEP file to hyper work

For open

Goto >> File >> Import >> Selct geometry >> Change to STEP >> Open the model >> Click the model >> Import

IMPORTING A MODEL

CHANGING TO STEP FILE

MODEL IMPORTED

DELETING SOLID FACES

Delete all solid faces for the given component

For deleting the faces

Goto delete >> Select surface >> Select solid under the surf >> delete

SOLID FACE OF INNER PANEL

DELETING SOLID FACE

INNER PANEL SOLID FACE DELETED

Do same for all other components

Here are the some snapshots of other components

OUTER PANEL

HINGE REINFORCEMENTS

LATCH REINFORCEMENT

GEOMETRY CLEANUP

Once the model is imported move to geometry cleanup just to check weather there any extra surface or free edges or missing surface will present or not

To check a errors

Goto visualize panel >> Disable shared edges and all except free edges

VISUALIZATION PANEL

Here no geometric error will found

CREATE A MID SURFACE

Once the model is geometric error free then move to midsurface

Now create a midsurface for a given components

Goto geometry page >> Select geometry >> Select midsurface >> Select extraction option as SKIN OFFSET

Now go back to auto mid extraction command

Auto extraction >> Select surface >> Select displayed under surface >> extract

EXTRACTION OPTION COMMAND

SELECTING DISPLAYED SURFACE

AUTO EXTRCATION WITH SURF

MID SURFACE OF INNER PANEL IS CREATED

Now RENAME the midsurface which we have extracted from the given component

Rename according to its parts

For rename

In left side of graphical part we can see one tab bar

Goto >> model view >> Rename >> Midsurface 1 as INNER PANEL

RENAMING THE MID SURFACE AS INNER PANEL

Fallow same steps for all other components also

Create a mid surface and rename the parts

MID SURFACE OF OUTER PANEL

MID SURFACE OF HINGE REINFORCEMENT

MID SURFACE OF LATCH REINFORCEMENT

RENAMING BY ITS PARTS

DELETE SYMMETRY MID SURFACES

Both inner and outer panel have symmetry surfaces so here we can safe a time while deleting symmetry surfaces and after mesh and quality cleanup we can reflect those symmetry portion

To delete the surface

Goto delete >> Select surfaces >> Delete

DELETING SYMMETRIC SURFACE

SYMMETRY SURFACE DELETED

DEFEATURING

In hypermesh, after you mesh a product for any kind of analysis, the end product is a meshed product. Most of the times it so happens that, some small holes or some small fillets or some small radii are left out which are not functional and unnecessary. We need to remove these unwanted features in order to obtain a final correct analysis. The process of removing these unnecessary, non functional features is called de-featuring.

defeature all unwanted lines which is less than the given minimum length

For defeature

Goto quick edit >> Toggle all unwanted lines

DEFEATURING ALL UNWANTED LINES

ASSIGN QUALITY CRITERIA

Assign quality criteria for a given model

Goto preferences >> criteria file setting >> Enter the values >> ok

QUALITY CRITERIA TAB

In this model some of the fillet region is failing for minimum length so here we have create a mid line and toggle all unwanted lines which is failing for minimum length

Goto lines command >> Select mid line >> Select 1st line middle click >> Select 2nd line >> Create

MID LINE IS CREATED

Now toggle all unwanted lines which is failing for minimum length

MESHING

FEA stands for the finite element analysis which means that elements are analysed and integrated over a region to derive the final result. so in a continous member, which in reality are everything starting from a pin to automotive parts. there are infinte nodes and its not possible to slove an infinite eqaution. so meshing is carried out so that we can discreting that continous member into number of finite nodes. and hence go for solving the equations. after that interpolate the results for entire domain.

Mesh the given components with a given quality criteria

Goto geometry page >> Select 2D >> Select automesh >> Select surface >> Create

MESHING COMMAND

Improper mesh flow

For better mesh flow we need to fallow some rules :

• Opposite tria's are avoided.
• Flat surfarce trai's should be avoided by merging them using split.
• Avoid trai's near to hole region.
• Hole feature should be in even numbered.
• Avoid tria's at the perimeter line.
• Avoid zig-zag mesh flow.
• Avoid rotating quads.
• Divides the large surface into small parts using split for meshing.
• Defeature the area which are going to fail the quality criteria.

PROPER MESH FLOW

For better mesh flow split the surfaces and create a mesh

INNER PANEL

HINGE REINFORCEMENT

LATCH REINFORCEMENT

OUTER PANEL

QUALITY ERROR'S CLEANUP

Clear all the quality errors which are failing for the given quality criteria

MAXIMUM ERROR

To clear this error we have

Goto quality index tab

Perform Swap, Split, Smooth etcc..OR

Remesh the particular area

QUALITY INDEX TAB

ERROR IS CLEARED

WARPAGE ERROR

This is warpage error

To clear this error we have to use translate command by click SHIFT F4

TRANSLATE COMMAND

Select node to transfer and give orientation for that node and translate node by giving 0.05 magnitude

so that the error will clear

WARPAGE ERROR CLEARED

LEARNING OUTCOMES:

1. Learned how to fix the geometrical error's to clean up the geometry .
2. Learned how to create midsurface for the each component .
3. Learned how to fix quality errors .
4. Learned how to meshed as per the given quality criteria .
5. Learned how to reduce opposite tria's and rotating quad's .

RESULT: The mesh is created for the given model as per the given quality criteria using HYPERMESH

CONCLUSION:

In the above hood model successfully generate mid surface and mesh the model as per the given criteria here i achieved 0.69 of tria percentage which is under the given criteria and with zero quality error's .