Assignment 1-2D Meshing Challenge

Aim-

• To perform preprocessing on all three model given according to qaulity criteria required for this challenge.

Objective-

• To import the model and perform geometrical cleanup.
• To extract midsurface for all the three components.
• To perform geometry cleanup on midsurface as well like defeature and holes less than 5 mm.
• To mesh the midsurface according to given quality criteria.
• To clear all the failing elements from quality.
• To assign the thickness to mesh to meet the component requirnment.

Procedure-

Satge-1

Import the model-

Model 1-

• Since we are importing the CAD file model in this challenge.
• So there are many type of file like IGES,STEP and parasolid we can use if we are importing a file into any CAD and CAE software.

But here in hypermesh we can use only three kind of file format:

1. IGES(Initial Graphics Exchange Specification).
2. STEP ( Standard for the Exchange of Product Model Data).
3. SolidWorks.

Now these time most of the industries started working parasolid file formate also.

[Note: While importing the file into graphical user interface be sure that whether the file is .step or .iges file. Otherwise we will face difficulty during importing the model.]

Tool we use to import in the way: File >> Import >> Import Model >> File type >> Open File.(As shown in below picture)

Imported Model-

• Now we will check for the solid body after converting it into by topo model.
• After putting the model in by topo mode if model is having solid then it will show in green color.
• For deleting the solid Go to delete panel (F2) > select solid > select by displayed > Delete.

[Note- But here we can see that there is no solid inside the CAD body.]

Stage 2-

Geometry cleanup :

So after importing the model we will go for check the model for any geometrical glitch lik,

1. Unnecessary surfaces.
2. Free edges.
3. Damaged geometry.
4. Unwanted connection between surfaces.

• Now we will try to get rid off these geometrical issues.
• For that f\red colour free edges we will do toggle,

Go to geometry > quick edit > Toggle > select the red lines > middle click

Note- It will ask about the value for toggle, set it as minimun as required to cover this toggle.

• Use fillet surface to complete continuous surface,

• Simmilarly we will do for all free edges.
• After that we can see a unncessary surface here,

For that wew will trim the extra surface and delete as follows,

Go to Geo > surface edit > Trim with surface > select interselcting surface > middle click

• Now delete the intersecting surfaces,

Stage-3

Midsurface extraction:

• As we can see here auto midsurface extraction is not practical so we will try to extract the midsurface manually.
• For that we have to check for the thickness for the components.
• Click F4 > distance between points > select points > Distance displayed now do half of that (1.4 unit).
• Now we will use automidsurface extraction since thickness is uniform.
• Go to geometry>midsurface > extraction type as skin midsurface > auto extract

Geometry cleanup on midsurface-

• As we can see there are most of the lines are closer to each other in respect to meshing.
• If we will perform meshing mehsing then elements might fail minimum size.
• So toggle those line in order to maintain feature.

Model is ready for mesh,

Stage-4

Meshing-

• Now we will start meshing the components part by part.
• And during meshing key points we need to take care about it.

Given Quality criteria for this model:

Target Element Length = 5 Units

S.N. Quality criteria

1 Min.Length shortest length of any given element 3.5

2 Max.Length largest length of any given element 7

• Criteria file setting

Key points for start meshing:

1. Try to provide simplest kind of mesh elements in order to avoid failure.
2. Provide smoother mesh in complex areas also because ananlysis we be based on our mesh.
3. Start with coarse mesh and understand the modeling results.

• so like this we will get proper mesh flow.

Final meshed model,

Stage-5

Assigning thickness-

• To assign the thickness create propert first

• Property is created now as 0.91mm.
• Now we will assign this property to the component.

Right click on component and select assign,

• Now after assigning the thickness,
• Switch on to 2D detailed elements representation.

Final model after assigning thickness.

NOTE:

• Simmilary we will perform pre-processing for to other two components.

Model-2

Stage-1: Import

Stage-2:Midsurface extraction-

Stage-3:Geomtry cleanup

Stage-4:Mesing

Stage-5: Assigning Thickness

Model-3

Stage-1: Model import

Stage-2: Midsurface extraction

Stage-3:Geometry cleanup for midsurface

Stage-4:Mesing

Stage-5:Assigning Thickness

Result-

• Midsurfaces extracted for all the 3 models.
• Geometry celanup performed for parent body and midsurface also.
• Meshed the midsurfaces of all three models.
• Thickness has benn assigned for all three models.