Challenge

Project 2

AIM: To model the given component by Mid surface and Tetra mesh depending on the need and provide appropriate connection to the same

PROCEDURE:

Step 1:-

Once the model is imported into the software , firstly perform TOPO and check for the Geometry error

The above image shows the number of geometry error present in the model, try to fix manually or using Auto option

Step 2:-

Once all the errors are fixed next step is to segregate parts which are having thickness less than 5mm
Mid surface will be extracted and meshed to parts having thickness less than 5mm
Parts with more than 5mm thickness will be considered as solid and tetra mesh is performed.
For the given model there are different quality criteria for different sets of parts
Tyre and rim has one quality criteria, Other solid parts has a seperate quality criteria and parts less than 5mm thickness has different quality criteria
Save all the differnt quality criteria and mesh parameters seperately

Step 3:-

Above image shows the mid surface extraction by offset option by giving the value as half the thickness
Set Property ID for the mid surface extracted and assign the respective thickness
Mesh the mid surface according to the given quality criteria and make sure there is no OFF elements

Above image shows there is zero OFF elements and the mesh satisfying the criteria

Step 4:-

Next step is to perform mesh on the solid in mesh deck and assign the volumes for each part in volume mesh deck
Isolate each parts and start meshing the circular region using ortho tria elements and flat region using tria elements

De-feature the Features which does not satisfies quality criteria
Make sure there is no maximum and minimum length error are present in the solid mesh
Repeat same step for all the other parts except tyre, rim and Spring.
Below image shows the solid mesh of all the other parts, No OFF elements present

Step 5:-

Step 4 should be carried out for tyre and rim portion, only difference is change in quality criteria

Step 6:-

Next is to model spring component as 1D bar element(in Reference to WEEK 6 Session 3 article)
Create middle curve for the spring, select the curve and assign CBAR element
Measure the dia of the spring , so it will be helpful in assigning the area for the 1D element

Step 7:-

The volumes has to be assigned to the solids in volume mesh deck
isolate the meshed body and define the volume by Volumes>Define>Auto
Defined volume will be in list without mesh, right click and remesh(as shown in below image)

Now the mesh can be performed in either Tetra rapid or tetra FEM algorithm(As shown below)

Try fixing the tet collapse issue by fix quality option if the error occurs somewhere inside the volume
If error occurs on the surface , then use MV free option and try to adjust the kinks and rise edges
Make sure there is no Kinks and Rises in volume

Step 8:-

Next step is to move to nastran deck and establish all the connections which is present
Provide Rigid body connection wherever required using RBE2 many nodes option
RBE2 two nodes option will be used to represent the body of the bolt
Next is to establish connections of seam weld
Convert the cons to Curve and convert the curve into seam line(as shown below)

Using connection mangaer define the weld PID, type of weld like Y-joint shell or Overlap shell
If the two bodies to be welded are parallel to each other use over lap shell
if the bodies are perpendicular to each other use joint shell
Weld definitions are shown in below image

Step 9:-

Once all the rigid body connection and seam weld connection are done
Enable draw Shell as solid for the mid surface created and enable Line elements cross section>draw mode > solids for 1D bar element as show in below image