Week 4

Objective:  To check the component for geometrical errors and mesh according to the given element Quality criteria and extracting the midsurface.

The given element quality criteria is:

Procedure:

1) After importing the geometry in ANSA, topo is performed in order to get a refined geometry. By selecting the length tool from perimeters under mesh. The value given was 1mm. 

Fig: Assigning length parameter to the whole geometry

2) In order to check for the geometrical errors, geometric check is performed on the component. Various errors are displayed such as needle faces, unchecked faces, triple cons etc. Auto fix option was opted for resolving these errors. 

Fig: Applying geometry check and auto fix option.

3) Extracting midsurface: Before generating the mid surface of the geometry, the thickness was measured. It is found that the thickness is not uniform across the component and hence shell meshing is to be done. For obtaining the mid surface, manual method was used which included multiple tools like offset, middle(multi and single). Features like Extend, cut and generate faces were used wherever deemed necessary. 

Fig: Extracted mid surface of the geometry

The regions created in the mid surface extraction are assigned with appropriate properties (thickness) using PID

Fig: Assigned properties

4) Meshing: Required values are specified in the element quality criteria. Average/target length is specified in the "mesh parameters" as well. 

Fig: Values for the quality criteria.

After feeding in the required values, mesh check was run from the checks manager in order to obtain and rectify the errors in mesh quality, and thus, improve the quality of the mesh. 

Fig: Obtaining the errors in the mesh quality. 

For meshing, batch and best mesh methods were used. Spot mesh was used for some regions as well. Errors related to max/min length were fixed by using the num+/- feature under perimeter. Reconstructing was done to obtain new mesh. 

Thickness to the shell is assigned by using the "draw shell as solid" feature in the quality criteria as shown in the figure below.

Conclusion: Geometry cleanup was performed on the given component (bottle cap). Midsurface was extracted using various features, keeping in mind the varying thickness of the geometry. Meshing was done pertaining to the given element quality criteria and mesh quality was further improved using features available in the mesh module.