Assignment 1-2D Meshing Challenge

OBJECTIVE:

• Carry out geometry cleanup operation on the given models.
• Extract midsurface.
• Clean midsurface geometry.
• Ignore holes less than dia 5mm.
• Create 2D mesh with target length 5mm, min 3.5mm max 7mm.
• Assign proper thickness, by creating a generic property.
• Save in .hm format.

PROCEDURE:

Part 1:

• IMPORT:
• Given model is imported to Hyperworks using import model option.

• Part-1 Topo View:
• The given model is viewed in topo mode to view the surface edges.

• Geometry Cleanup of Part 1:
• Since the topo mode view shows the surface irregularities in the imported model, it should be cleared before the midsurface of the model is obtained.
• The geometric cleanup of the imported model is done using the follwing tools:
• For missing surfaces, filler surf option under quick edit tab is used
• For Disconnected edges, toggle edge option under quick edit tab is used.

• MID-SURFACING:
• Mid-surface of the closed solid is extracted using midsurface tool under Geometry tab.
• automidsurface is used to obtain the mid-surface.
• Midsurface generated is stored under seperate collector named Middle Surface.
• The extracted mid-surface is shown below placed exactly in the middle of the given model.

• GEOMETRY CLEAN-UP:
• Geometry cleanup is done with the help of autocleanup tool under Geometry tab.
• Some of the edges are manually suppressed using toggle edge option under quick edit panel.
• Since the hole diameter is greater than 5mm, it is left unsuppressed.

• Larger surfaces are further divided using split surf-node/split surf-line option under quick edit panel to obtain a proper mesh.

• MESHING:
• After the cleanup is finished and each component is divided into smaller and simple surfaces to obtain proper mesh.
• The meshing is done by using automesh tool under 2-D tab with elements size as 5 and element type as mixed.
• The meshing of each component is done surface wise from one small surface 

• Similarly meshing is progressed into adjacent attached surfaces to mesh the whole model. 

• QUALITY Check:
• The meshed elements of all components are checked using qualityindex tool.
• The elements violating the specified quality criteria are marked yellow and red. 
• Cleanup tools like element optimize and place node within the qualityindex is used to optmise the violating elements.
• For elements which are not optimized to within the criteria range with qualityindex tool, elem cleanup tool is used. 
• In situations where qualityindex and elem cleanup tools failed to rectify the violating elements, automesh tool is used to remesh the non-optmized elements.
• The elements of the all components are checked if any more violating elements are present.
• If present, the above steps are repeated until all elements fall under the given quality criteria.

• Projecting Nodes to Surface and Lines:
• For nodes of the elements that may deviate from the surface edges during the meshing or quality cleanup procedures, Project option under tools tab is used inorder to make the nodes properly capture the model geometry.

• Assiging Property:
• After meshing and quality checks, the elements are assigned with thickness.
• Inorder to assign part thickness to the elements, a property component is created and thickness of 0.91mm ( Model thickness) is defined.

• Created elements are then moved to parent component from the mid surface component using organize option under tools tab.
• Parent component is also assigned with the created thickness property.

• CONCLUSION:
• Hence carried out geometry cleanup operation on the given model.
• Generated the Midsurface of the given geometry and performed geometry clean up of mid surface.
• Meshing performed on the generated midsurface with elements under the given quality criteria.
• Thickness assigned to the created elements.
• Model File saved as Part1.hm

Part 2:

• IMPORT:
• Given model is imported to Hyperworks using import model option.

• Part-2 Topo View:
• The given model is viewed in topo mode to view the surface edges.

• Geometry Cleanup of Part 2:
• The model part2 when viewed under topo mode do not have any sort of geometrical error hence no geometry correction was required.

• MID-SURFACING:
• Mid-surface of the closed solid is extracted using midsurface tool under Geometry tab.
• automidsurface is used to obtain the mid-surface with skin offset as the extraction option.
• Midsurface generated is stored under seperate collector named Middle Surface.
• The extracted mid-surface is shown below placed exactly in the middle of the given model.

• GEOMETRY CLEAN-UP:
• Since all the hole diameters are >= 5mm, it is left unsuppressed.

• Geometrical points and lines as shown above will make the elements fail or make them away from the surface edges, which is cleared using replace point option under quick edit tab

• Washer split is also added to the top surface holes on the model. Other holes are removed using filler surf option under quick edit tab.

• MESHING:
• After the cleanup is finished and each component is divided into smaller and simple surfaces to obtain proper mesh.
• The meshing is done by using automesh tool under 2-D tab with elements size as 5 and element type as mixed.
• The meshing of each component is done surface wise from one small surface 

• Similarly meshing is progressed into adjacent attached surfaces to mesh the whole model. 
• Reflect tool and Position tool is used to reflect and position elements to the surfaces which are symmetrical.

• The remaining portion can be meshed using ruled option under 2-D tab.

• Projecting Nodes to Surface and Lines:
• For nodes of the elements that may deviate from the surface edges during the meshing or quality cleanup procedures, Project option under tools tab is used inorder to make the nodes properly capture the model geometry.

• Connectivity Check:
• inorder to obtain mesh on the whole surface, Reflect, Position and Ruled options are used which creates disconnectivity between the elements.
• This is checked using the edges tool option under the tools tab.

• Here there is a disconnectivity between the elements, which is removed using equivalence option under edges tool.

• Assiging Property:
• After meshing and quality checks, the elements are assigned with thickness.
• Inorder to assign part thickness to the elements, a property component is created and thickness of 0.91mm ( Model thickness) is defined.

• Created elements are then moved to parent component from the mid surface component using organize option under tools tab.
• Parent component is also assigned with the created thickness property.

• CONCLUSION:
• Hence carried out geometry cleanup operation on the given model.
• Generated the Midsurface of the given geometry and performed geometry clean up of mid surface.
• Meshing performed on the generated midsurface with elements under the given quality criteria.
• Thickness assigned to the created elements.
• Model File saved as Part2.hm

 Part 3:

• IMPORT:
• Given model is imported to Hyperworks using import model option.

• Part-3 Topo View:
• The given model is viewed in topo mode to view the surface edges.

• Geometry Cleanup of Part 3:
• The model part-3 when viewed under topo mode do not have any sort of geometrical error hence no geometry correction was required.

• MID-SURFACING:
• Mid-surface of the closed solid is extracted using midsurface tool under Geometry tab.
• automidsurface is used to obtain the mid-surface with skin offset as the extraction option.
• Midsurface generated is stored under seperate collector named Middle Surface.
• The extracted mid-surface is shown below placed exactly in the middle of the given model.

• GEOMETRY CLEAN-UP:
• Geometry cleanup is done with the help of autocleanup tool under Geometry tab.
• Some of the edges are manually suppressed using toggle edge option under quick edit panel.
• Larger surfaces are further divided using split surf-node/split surf-line option under quick edit panel to obtain a proper mesh.
• Holes upto 5mm diameter is avoided by using filler surf tool under quick edit tab.

• MESHING:
• After the cleanup is finished and each component is divided into smaller and simple surfaces to obtain proper mesh.
• The meshing is done by using automesh tool under 2-D tab with elements size as 5 and element type as mixed.
• The meshing of each component is done surface wise from one small surface 

• Similarly meshing is progressed into adjacent attached surfaces to mesh the whole model. 
• Reflect tool is used to reflect elements to the surfaces which are symmetrical.

• Connectivity Check:
• inorder to obtain mesh on the whole surface, Reflect, Position and Ruled options are used which creates disconnectivity between the elements.
• This is checked using the edges tool option under the tools tab.

• Here there is a disconnectivity between the elements, which is removed using equivalence option under edges tool.

• Assiging Property:
• After meshing and quality checks, the elements are assigned with thickness.
• Inorder to assign part thickness to the elements, a property component is created and thickness of 0.91mm ( Model thickness) is defined.

• Created elements are then moved to parent component from the mid surface component using organize option under tools tab.
• Parent component is also assigned with the created thickness property.

• CONCLUSION:
• Hence carried out geometry cleanup operation on the given model.
• Generated the Midsurface of the given geometry and performed geometry clean up of mid surface.
• Meshing performed on the generated midsurface with elements under the given quality criteria.
• Thickness assigned to the created elements.
• Model File saved as Part3.hm

All the 3 Models have been saved under .hm file format: