Week 4

AIM: To extract manual mid surface of Bottle Cap and meshing the same by given quality criteria

PROCEDURE:

Step 1:-

• Firstly perform TOPO on the model as soon as it is imported and do a check geometry for errors

• fix errors by right click on the same and slect fix(Auto fix)
• if auto fix is not working then manually user has to find the error and rectify the same
• below image is the representation once the errors are fixed

Step 2:

• Measure the thickness of each and every faces and offset the same by giving the half value
• for example if thickness is 2mm give the offset value as 1

• in this case the offset is given as negative valie, keeping the direction in consideration

Step 3:-

• after taking the offset of simple faces next is to take mid surface for ribs
• in order to mid surface for ribs we will be using multi mid option

• In the above image red will represent the inner face and green will represent outer face and finally blue will represent the thickness

Step 4:

• The corresponding face which is in contact with ribs will have gaps in mid surface

• In order to close the gap use Faces>New>Existing surf

• Extend the mid surface of ribs to the cylindrical face

Step 5:-

• Next step is to extract mid surface of complicated surface like "threads" and "tooth"
• firstly create the middle curve by slecting the cons of the thread

• project the middle curve on mid surface by CONS>Project option as shown below

Step 6:-

• create the mid surface for the tooth by taking middle curve

• Project the other edge on the mid surface and connect the middle curve and projected con to form the tooth mid surface

• Rotate the entity by using transform operation
• create COG point by selecting two circles with different heights

• using the two COG points rotate the entities by givng the angle as 360/25

• Final output will be as shown below

Step 7:-

• After creating the mid surface for all the faces move to mesh module
• assign all the quality criteria which as asked to maintain

• assing the perimeter and macros value by giving targeted length

Step 8:-

• Mesh is created by Mesh generation> Best
• check for OFF elements and try to rectify the problem by reconstruction, fix quality , smooth etc
• once the OFF elements became zero
• Correct the mesh flow

• Finally assign the thickness by Quality Criteria>presentation parameters> Draw shell as solid

LEARNING OUTCOMES

• In this particular challenge understood how to improve the OFF elements
• Defeaturing the features which are not satisfying the minimum target lenght
• understood mid surface extraction of varying cross sections, threads and some of the other complicated surfaces
• understood what all problems we can expect in plastic and casting products
• The level of complexity the challenge had, it made me to invlove more in the tool and understood the working of different commands
• understood the optimised way of usind the commands

CONCLUSION

• The given model is meshed and assigned the thickness as mentioned