Week 4

Aim :

To create mid surface and to mesh the given CAD Bottle cap geomentry with good quality criteria using the ANSA software.

• Import the geomentry to the Ansa software.
• Check the geomentry using the checks manager.
• Measure the geomentry and store them.
• Extract the mid surface manually.
• Give the thickness to extracted midsurface.
• Mesh the mid surface geomentry with good quality criteria.

Procedure :

Step 1 : Import the cad Bottle cap geomentry to the ansa software, after importing the geomentry it has so many suface errors we need to fix those before checking the geomentry using the topo option and tben go to mesh and select the length and give 1mm of perimeter and macro, thus geomentry is fixed.

Step 2 : Now we have to check the geomentry using the checks manager and select the geomentry and execute it and look for errors. If the errors can be fix by auto we can fix the errors, if it is not we have to do it manually.

Step 3 : Now we have to give quality criteria for the given geomentry by using ' F11' option and apply it to the geomentry.

Step 4 : After looking into the geomentry we can see that model consists lot of features and variying thickness so auto midsurfaces is not possible we have to do it manually. To mid surfacing first we have to measure each and every ribs and threads and store them using Utillities > Measure.

Step 5 : Now we know the thickness of each feature so first we have to go with easy one that is which doesn't have more features so we have to mid surface for inner and outer surfs manually using the offset option.

Step 6 : After completly extracting the easy mid surfs now we have to go with the inner ribs, outter ribs and threads. To extract these type of features we have to use Curves > Middle option to extract middle curves of those features.

Step 7 : Middle curves are extracted with those we have to create the surfaces of features using the Faces > NEW > Coons option. Now we have to follow same steps for the outter ribs and threads.

Step 8 : Now we have extracted each and every part and we have to save the mid surfs in different domain, to do that on wire frame mode and on the hybrid boolean operation and select each and every surf and click middle button and lock it and create new lock manager. After that we have to give property to the each individual mid surfaces.

Step 9 : Now we have seperated the mid surfaces, looking at the mid surface geomentry all features and surfaces are free edges we need to fix this bring the geomentry as original one. To do this we have to use two options 1. Faces > new > coons 2. Faces > extend options, with this options we easily achieve the original geomentry mid surface.

Step 10 : Now we will move on to the meshing part here we will use best method alogorithm to mesh the mid surfaces individually. After meshing the each and every surface we will notice that there is off elements or failed elements.

Step 11 : Now we have to fix those off elements first we have use Shell elemnts > Reconstruction option for good mesh flow and for to remove off elements if it is not fixing it we have to use hybrid split option it will removes the off elements. For good mesh flow we will use smooth option also. To remove some trias use Grids > paste or Grids > Mv surf options.

Step 12 : Now complete mesh has done to the mid surfaces and check the thickness is assign to the mesh using F11 > Draw shell as solids option.

Result :

Thus we created mid surface and mesh the geomentry and assign the thickness to the Bottle cap geomentry.

This is the link for above model file : https://drive.google.com/file/d/1PiEXA0-JGCNSPou6BaHkPmp0zCB0KSdb/view?usp=sharing

Conclusion : Thus learned how to extract mid surface manually and especially for different thickness feature and for threads using curves middle and joining all featues to single geomentry.