Week 4 - 2D Meshing for Sheet Metal

Project Report on CCB MODEL (CROSS CAR BEAM ASSEMBLY)

Aim :- For the given CCB model, Take the mid surface for all the components after checking the geometrical errors and mesh the mid surface with the given element Quality criteria and after meshing assign the thickness. (Refer the table Below for the Quality criteria)

For the given geometry we have to set quality criteria

Few points must be Obey during the meshing

• No Tria element on the edges (free edge , share edge ,non- manifold edges, )
• No opposite trias in the Mesh
• Not trias should touch each other (no back to back trias)
• No trias must touch features (Embosses,Fillets , Holes, Logos, Dog Houses, Weldings etc.)
• There should be an even number of nodes on the holes opening
• No rotational quads
• No pattern Trias

Now first we have go for check geometry to eliminate all geometrical errors

For that we have to follow the following step :-

1) First we go to mesh module under this perimeter we select length option after left clicking on that option we select the whole model by midle mouse click we set a value 3 and click ok. By doing this in the geomtry the distance between any two nodes will be 3 unit after that we go for topo operation topo>faces>topo very frequently

2) After that again we go to check>geometry>execute there are so many errors found one by one we resolve the errors and again go for check>geometry>execute and repeat this cycle until all the geometrical errors are eliminated

3) After geometrical cleanup, we have to do Mid-surface extraction for that we go to topo>faces>Mid-surface, for sheet metal we select skin option because here thickness is constant , So by clicking on the option we have to select each part at a time and after midle mouse click , it will auto assign the offset value and we have to click offset , but here we need to pay attention while doing offset because the parent will be deleted after doing this , so for that we again goto topo>Faces>Undelete after clicking on it select entire element and we got our parent geometry after this we need to do Topo and finally we got our mid surface

Note:- here images given in a sequential manner

4) After that new mid surface will be created in the midle of the thickness of the plate

5) We have to assign property id for that we goto Topo>Faces>Set PID, by left mouse click we select one element and assign PID for the mid surface similarly we are doing this for all the elements

Here PID's are given below

6) Now we are proceeding to Meshing part , for that we have to work on part by part rather than whole geometry with the help of PID's, for that we select a particular PID and switch off remaing , goto Mesh>perimeter>length under perimeter selecty the whole and give value 3 click midle mouse i.e the distance between any two nodes will be. After that we are proceeding for meshing goto

Mesh>Mesh Generation>Best select the entity or area as per convinient and click midle mouse and mesh will be generated

7) After that we go for Quality criteria by pressing F11 putting all the values given in the assignment and click ok

8) After meshing we observe that there some quality issue (after apply quality criteria) , so we have to resolve them by frequently using Reconstruction (mesh>shell mesh>Reconstruction),

smooth (mesh>shell mesh>smooth)

and split (mesh>element>split) , swap (mesh>element,swap) , join (mesh>element>join), paste (mesh>grids>paste), in paaste option we are going to paste two nodes according to our requirements

9) Now we rectifying all issue we got our mesh flow perfect and after this we assign the Thickness for that we goto seperate PID's and assigning the thickness we can see this under quality criteria > presentation parameter>click on draw shell as solid and we can see our assign thickness

example

Now we have completed our assignment

THANK YOU