Project 1

PREPROCESSING OF IP SUBSTARTE USING ANSA

Aim: To extract mid-surface and generate mesh on IP console.

Software Used: BETA CAE ANSA.

Steps Involved:

1. To Import geometry and check for geometrical errors.
2. To extract the mid-surface and assigning PID.
3. To mesh the geometry within the given quality criteria.

Quality Criteria:

S. No	Quality Criteria	Value
1.	Target/Average length	4
2.	Minimum Length	2
3.	Maximum Length	6
4.	Aspect ratio	3
5.	Skewness	45
6.	Warpage	15
7.	Jacobian	0.7
8.	Minimum Quad Angle	45
9.	Maximum Quad Angle	135
10.	Minimum Tria Angle	30
11.	Maximum Tria Angle	120
12.	Tria %	15

Tools used during Geometry cleanup:

1. Checks manager: It is used to check the errors in the geometry
2. Release Cons: It is used to convert the triple cons into single cons
3. Insert: It is used to insert a point on the cons.
4. Topo: It is used to join the cons.
5. Orient: It is used to change the orientation of the system.
6. Fine: It is used to change the resolution of the 3D surfaces.

Tools Used during extraction of Mid surface:

1. Offset: It is used to create cons or curves within the specific distance.
2. Middle: It is used to create the Mid surface by selecting the sides of the geometry.
3. Extend: It is used to extend a face.

Tools Used during Mesh Generation:

1. Num +/-: It is used to increase or decrease the nodal number along the perimeter.
2. Number: It is used to set edges number on perimeter segments.
3. cut: It is used to cut an existing macro area from one node or Hot Point perpendicular to another selected perimeter.
4. Best: It is used to generate mesh using all alternative pre-define algorithms and keep only the mesh of best quality.
5. Reconstruct: It is used to Re-generate the mesh on FEM and Macro Areas.
6. Smooth: It is used to Smoothing the mesh on selected Macro Area or FEM.
7. Split: It is used to split shell and solid elements into smaller by selecting element edges and nodes.
8. Swap: It is used to rotate the common edge of two shells.
9. Join: It is used to join the triangular elements together.

Procedure:

1. Importing geometry and checking for geometrical errors:

• To import geometry, select file >> open >> select the file. After importing geometry perform topology on the model.
• Now we should check for geometrical errors. To check for errors, select checks manager >> Geometry >> Execute.
• Fix all the errors either manually or by using auto fix option. After rectifying all the errors, the geometry is ready for extraction of mid-surface.

2. Extracting the mid-surface and assigning PID:

• Measure the thickness using measure option which is present in utilities deck.

• After measuring the thickness, mid-surface can be generated using any of the following options.
• To generate mid-surface for the component whose thickness is even the offset is used. To use the offset option, select offset present in faces and select the faces whose mid surface is to be generated and then enter the mid value of the thickness.

• For the feature and uneven thickness components middle option is used. Middle option present in faces is used to generate the mid-surface. After selecting the middle option, the sides of the component are selected in order to create a mid-surface.

• Extend option is used to extend the faces to make a connection between the parts.
• After generating the mid-surface, the PID is created and respective thickness is assigned to the parts.
• To create the PID, select property manager present in lists deck then right click in the property manager and select new >> PSHELL >> PSHELL.
• After creating the PID, to assign the thickness and parts to the PID, right click on the PID and select apply and then select the parts and assign the respective thickness.
• The image below is the mid-surface extracted from the IP console.

3. Generating mesh within the Quality Criteria:

• Before generating the mesh, the Quality criteria should be given by pressing function f4 or by choosing quality criteria in utilities section.
• After giving the quality criteria, the mesh parameters should be given.
• To generate the mesh one can, use either Batch mesh or Best mesh option present in mesh generation section.
• Best mesh gives the good mesh flow compared to Batch mesh. After selecting the mesh option, we can either select the entire surface to mesh or we can divide the surface into smaller areas using the project cut option present in the macros section.
• To achieve the good mesh, flow the surface can be divided into rectangles where ever it is possible. After dividing the surfaces into rectangles, each rectangle can be meshed individually.
• If there are any fillets present on the geometry, good mesh flow can be achieved by making a horizontal cut (using proj.cut) can be made.
• If the mesh flow is not good, Reconstruct or Smooth option can be used to either to regenerate the mesh in the selected area or smoothen the mesh flow without regenerating.
• If there are tria elements present at the perimeter of the surface Num+/- option can be used to remove the trias and generate quad element at the perimeter.
• If two tria elements are adjacent to each other join option present in Elements can be used to form a quad element.
• After generating the mesh on the entire surface, the cuts made using proj.cut option are to be removed.

>> IP console after meshing with given Quality criteria is shown in the image below:

>> IP console with assigned thickness is shown in the image below:

Learning Outcome:

• Perform topology and clear the geometrical errors.
• Assign separate PID for different parts.
• Meshing geometry with the quality parameters.

Conclusion:

For the given model topology cleanup is performed, mid-surface is generated and meshing is done within the given quality parameters.

Model file link:

https://drive.google.com/file/d/1vSjaEP7Q1NwBnJueOw_tMCwp1m3MZhs_/view?usp=sharing