Challenge

Project-2-Meshing of Door Inner Panel Challenge

AAshwini R B9 Jul 2024

Meshing of Door Inner Panel

Aim : To cleanup the geometry , extract the mid surface and to mesh component for the given quality criteria and to assign the thickness

Procedure:

To import the CAD geometry into Hypermesh

The file format will be in .IGES format or .step format

File > Import > Import Model > File type > Open File > Import File

Next switch to topo mode and check for solid in the component or not, if exists delete the solids by using delete option or F2

Delete [F2] >> Solids >> Delete solids

Check for geometrical errors like free edges ,unwanted points, damaged surface on the geometry, if any fix the errors
After cleanup the geometry , now measure the thickness of the component as it is a plastic model it is having varying thickness by using distance option

Geom>>distance>>two points

Midsurface:

Midsurface can be extracted by two methods ,auto midsurface as well as manual method. Here I have used manual method to extract the mid by using the option offset

Geom>>Surface edit>>offset

Select the surface to be offset then duplicate the surface,specify the thickness and now click on the offset the surface will be created

Mid surface for Ribs

Here we can extract the mid by defeaturing filets of the ribs by using the option defeature

Geom>>defeature>>surf filets>>find>>remove

After defeaturing the the ribs we can extract the mid surface by using manual offset method, so that mid surface will be created as shown below

As the manual offset of the Ribs are time consuming we can go for Translate command and we can transfer the rib mid surface according to the parent geometry

Tool>>Translate>> surfs>> Select the N1 and N2>> assign the magnitude value >>Translate

Defeature of the ribs is tedious processes in that case we can go for midline option

Geom>>lines>>midline>>select the line list>>Create

Midline will be created as shown below

Now, trim the surface using the midline.

Geom >> surface edit >> trim with lines >> select the free line and the surface that you want to trim >> trim.

The lines will be created as shown below

Now create a surface by using ruled option

Geom>>surface>>ruled>>create

Next by using extend option extend all the mid surface of the ribs to base surface to form connectivity

geom>>surface edit>>extend>>create

Mid surface of Locators

Locators helps to achieve accurate positioning during assembly, it has to be midsurfaced as ‘+’ symbol

Geom>>line>>extract edge>>lines>>create

Now trim the surface using the lines

Geom >> surface edit >> trim with lines >> select the free line and the surface that you want to trim >> trim.

Create a surface using ruled option

geom>>surface>>ruled>>create

Meshing:

Now all the mid surface has been extracted for the Ribs as well as for base surface geometrical cleanup has been done on the mid surface and is ready for meshing. Before meshing ,set the quality parameters as given for the component

preference>>parameter file settings>>basic>> target length>>apply>>ok

preference>>criteria file settings>>apply>>ok

If any unwanted construction lines remove them and capture the feature properly

Now start meshing the given component using auto mesh option

2D>>automesh>>surface>>mesh

The obtained mesh fails for quality criteria which can be corrected by remeshing by using rebuild option

2D > rebuild mesh >> select element >>rebuild

Next to maintain a proper connectivity of node to node for the meshed element,it can be checked by using the option edges

Tool>>edges>>elements>>find edges>>preview equiv>>equivalence

Final mesh model is as shown below

Assigning the thickness:

As it is a plastic component it is having varying thickness surfaces and ribs, so it has to be moved to separate collector by using the option organize

Tool>>organize>>collector>> select element or surface>>move