Week 3 - 2D meshing for sheet metal

The Objective of this project is to perform Preprocessing i.e. Geometry cleanup, mid surface extraction

and 2D Shell meshing for the hood component of a car. After meshing, component thickness and material

need to be assigned to the mesh. And the mesh should follow the following 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

Procedure:-

First, the hood model is imported into the Ansa.Then

open this file using File>Open>Hood Model.

Then after opening this file we will got five individual

components.

This five components shown in below,

                                            1. Outer Panel

                                               2. Inner Panel

                                    3. Latch Reinforcement

                               4 & 5. Hinge Reinforcement

After the importing model is to properly analyze and understand the geometry.

When CAD model is imported into the Ansa, there might be several geometrical

errors like missing/distorted surfaces, intersecting surfaces, etc. due to the format conversion

process bad model.

Then Take one part at one time then do firstly cons resolution.This is used for we got proper image

shape.Using this steps

Mesh>Perimeter>Length

Then give value of perimeter length 1.

After cons Resolution we gave  Orient tool. This orientation using because colour formed at particular at one

direction.

Topo>Faces>Orient

After Orientation we go to Geometry checkup tool. Here we checked our geometry good or bad like something

error are present or not. This errors like tripple cons, Single cons, needle faces, Collapsed faces, unchecked faces

cracks.

Then we select the error if present the error then this error to do autofix.

Then we got Our geometry check 100 percent ok in green colour.

Checks>Geometry>Execute.

After that we measure the thickness of model.

Utility>Measure

This thicknes we can measure using nodes, cons.

After Measure the dimension  we used midsurface tool . We using this because models midsurface extracting.

Topo>Faces>Midsurface.

After Midsurface extracting we switch off the parent geometry.

After that we gave quality criteria for the models and meshing size also.

After that we go to meshing.

Before meshing using cut and join tool. Because this is used for good mesh flow.

Cut used for split two surfaces and join used to convert the two faces into one face.

Mesh>Macros>cut

Mesh>Macros>Join.

After that mesh generation tool of the model. we used Best mesh for the model.

This tool generates the mesh using the best algorithm applicable.

Mesh>Mesh Generation>Best

Then , the created mesh is refined using Shell

We dont want trias and avoid the trias condition the used Reconstruction tool and Smooth tool.

Mesh>Shell Mesh>Reconstrucion.

We meshed the all components this figures shown below,

                                                            1. Outer Panel

                                                                 2. Inner Panel

                                                          3. Hinge Reinforcement

                                                            4. Latch Reinforcement

The deals with trias, the following tools are used,

Mesh>Grid>Paste, to paste the nodes and move tria backward.

Mesh>Elements>Split, to split an element and move tria forward.

Mesh>Elements>Swap, to move the tria left or right.

Mesh>Elements>Join, to join two trias to make a quad.

Conclusion:-

Geometry cleanup, mid surface extraction and 2D meshing of hood model done successfully.

And all the features in the model are captured properly with good mesh flow. Tria concentration

is kept low.