Challenge

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

HHitesh Kumar24 Sept 2022

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

Solution

first open the hypermesh and select optistruct profile

now import the file by going to file-import-Model(according to file type)-then hit import

now check for any geometrical error and repair it using quickedit,replace node,surface etc

Some geometrical error fixing

To repair geometry there are lots of tools but in the quick edit panel there is many options to repair the geometry

To go to quick edit

First go to Geom-Quick edit

1.Realease point

before after

2.Toggle

It is the tool by which we can supress the lines and stitch the free edges

with this you can supress unneccessary lines which will give errors in meshing

before supressing after supressing

Now to repair free edges

You can connect them using replace point in quick edit or just using toggle in quick edit

Now Go to Geom-quick edit-Toggle-and click on line

After clicking on line it shows

Now you can just increase the tolerance value but remember sometimes when the gap is large the geometry gets destroyed .

Fill the surface

if there is some empty surface like shown you can fill it using filler surf in quick edit panel.

Also try to be in Topo mode

and use wireframe mode to delete unneccessary points and lines which are not visible.

Also remove unneccessary points after their use because they can interfere in meshing later.

By using add remove point in quick edit panel

Now,After cleaning the geometry

Split the surface (it is optional but very benefcial for complex geometies)

First , decide where do you want to split and assign temp nodes there by going to Geom-Temp nodes-

and then click on line and then click multiple times and then click on create and make another one on another end.

and now creating nodes use split surface node from quick edit

And change the colour so you can distinguish between them

Now, Create mid surface by using OFFSET in ssurface edit option by going to

Geom-surface edit-Offset

now,to offset you have know the distance

To know the distance press F4 and select point first and second

for intance distance 2.79 we caan take it as 2.8 and half of 2.8 is 1.4.

so,put the value of offset to 1.4.

Now,After manual midsurface the outer surface like shown above

Now,move on to ribs before midsurfacing the ribs firstly defeature the ribs by

Going to Geom-defeature-assign min and max and then click on surfs and select the ribs

then click on remove and it will look like these

To create mid surface of ribs
First measure the distance of ribs and mark point between and then go to surface edit- offset and select one side surface of rib and offset upto point between.

After making all the ribs mid surface it's time to connect them to surface.
I have used two methods to connect the ribs to surface
1.go to Geom-surface edit-extend-select line and then select surface to extend then click on extend (in this method sometimes it damage the geometry).

2. method to extend

in this i will extend the other surface using this method,you can also use this method for ribs also.

go to Geom - surface edit- trim with lines -Then extend the surface to base surface by going to surface edit-trim with lines-select surf edges and then select surf then trim then go to Surface by going to Geom-surface-(ruled) - select lines and then create and same for other surface.

# NOTE In the below images i have trimmed it before and forgot to take screenshot so please don't mind it just to show how i did it

Now how to show this

First make the nodes and connect them through lines like shown below

Now use drag by going to 2D-drag-select lines-then give axis or N1, N2 and give the distance and then click on drag+ or drag-

Then extend the surface to base surface by going to surface edit-trim with lines-select surf edges and then select surf then trim then go to Surface by going to Geom-surface-(ruled) - select lines and then create and same for other surface.

done.

Now,to make this

now how to make a hole
first create mid points by pressing f4 and select point 1 and point 2 and select point between

create temp nodes
then make lines

then give radius and select n1,n2,n3

then split the hole lines and surf

then delete the surf of hole and hole is created
then delete temp nodes and lines

theen do similarly with others

Extraction of middle surafce is done.

NOW,MOVE ON TO MESHING.

NOW first check the criteria file settings and match them with question.

by going to peference--criteria file settings

Now go to 2D-Automesh-select surf-mesh

NOTE:do not mesh whole surface at one time and mesh separately using split surf node by going to quick edit option.

Now,go to 2D-Automesh-select the surface and select mixed and give the value 4 for target element size and then click on mesh.

Now,try to minimise the tri elements as much as possible
Things i have done to minimise the tria elements

Rebuild mesh multiple times by going to 2D-rebuild mesh

Go to quality index by going to 2D-quality index and check how many elements are failing and worse conditions and correct them using cleanup tools in quality index.