Week 12:Project-1-Meshing of Door Inner Panel Challenge

AIM:- Meshing of Door Inner Panel

OBJECTIVE:-

Follow the Quality Criteria and mesh the following component and assign thickness:

Target Element Length = 4 Units

S.N	Quality Criteria	Value
1	Aspect Ratio	5
2	Skewness	45
3	Warping	15
4	Taper	0.5
5	Min. Length	2 Units
6	Max. Length	6 Units
7	Min angle Quad	45
8	Max angle Quad	135
9	Min angle Tria	20
10	Max angle Tria	120
10	Tria %	10

INTRODUCTION:-

1.Car Side Door Panel

The side door panel is the plastic part. materials used for the door panel are acrylonitrile-butadiene-styrene (ABS), ABS/polycarbonate alloys, Polypropylene (PP).

Properties

1. High weathering resistance

2. High strength and toughness up to 140°C

3. Very good heat resistance

4. good processing characteristics

5. Remail flexible down to -150°C

6. High rigidity

7. Good impact resistance

In the fig0.2 Shows the example for the side door panel.

Procedure:

The meshing is done by following steps

1. Import side_door_panel.hm in to Hypermesh

2. CAD Geometry clean up and topology

3. Mid-surface extraction

4. Defeaturing

5. Shell meshing

6. Creating properties and Thickness assigning.

1. Import Side_door.hm in to Hypermesh :

file>open>model, browse the file and open. in the figure 1.1 shows the model.

CAD Geometry clean up and topology: In this step the given model undergoes geometry check.

Where all the defects such as collapsed faces, cracks, free edges,

Surface.

Tools used in topology

Tools>Edge Edit Panel

A. Equivalence (multiple edges at a time) Search surfaces for pairs of free edges and combine into shared edges

B. Toggle (edge pair at a time) Select an edge; equivalences with other free edges found within a user specified tolerance

C. Replace (1 edge pair at a time) Select 2 edges to equivalence together. Control which edge to retain and which to move.

D. Geom>Surfaces>Ruled or Geom> Quick edit > filler surface or 2d> spline> surfaces only (to create missing surfaces).

In the given model there are so many defects. fillets which are very small and should be defeated. In the fig. 2.1 shows some defects.

Defeature all small fillets by using

steps

a. Geom>Defeature>surface fillets.

b. Use the Surf Fillets subpanel to identify and remove surface fillets (curved surfaces that create a smooth transition between relatively perpendicular geometric entities).

You can identify fillets based on radius, because fillets are always uniform arcs.

You can also select a fillet by picking one of the edges that it connects.

Once found, fillets can be removed using tools that display automatically after the find process.

c. By clicking on remove all selected fillets will be removed.

Fill missing surfaces using line drag: Use the Drag Along Line subpanel to create surfaces by dragging lines or a node list along another line, called the "drag line".

Steps

a. Select the lines or node list to drag.

b. Select the lines that the drag will follow.

This can also be a series of connected lines.

c. Merge the input lines into smooth lines when possible, and create a surface for each group that forms a tangentially continuous line.

Clear this checkbox to create a surface for each input line, with shared edges connecting surfaces where relevant.

d. Choose where to organize the resulting surface component.

3 Mid-surface extraction:

The given model is a side door panel and before going to the Mid surface extraction check for thickness of entities and measure (Geom>distance).

We found different thickness on each feature. For the parent we have T 2.8 units.

To simply extraction of mid surface. models divided in to two components shown in the fig 3.1

Mid surface is done by manually using offset (Geom> surface edit> offset). offset panel shown in the fig bellow

Steps

a. select offset

b. Offset moves the selected surfaces without retaining their connections to surrounding geometry.

c . select the surface and make a duplicate of same surface

d. input the value which is half of the thickness

e. to check the direction click on vector normal so that we can see the offset direction, also one can change the direction by reverse normal

Direction of offset
for all ribs extraction of mid one file final edit tool from Midsurface. (Geom>midsurface>final edit tool) show panel below

Select a surface that represents one side of the solid.

Select a surface that represents the second side of the solid.

Select extraction options accordingly to define which surfaces to take into account when constructing midsurface.

By default, only two surfaces that are selected with the side1 and side2 surf selectors are considered.

To take into account offset directions of the adjacent pre-existing midsurfaces, select the use adjacent midsurfaces checkbox.

To allow modifying pre-existing adjacent midsurfaces, select the combine with

RESULTS:

For the given Side door model we have extracted the mid surface and meshed it without any errors for the given quality criteria. Here are some images of the given model.