Week 4 - 2D Meshing for Sheet Metal

Objective:

1. To mesh the components of Cross Car Beam to qualify the given quality criteria
2. Assemble the CCB by using appropriate connections

Quality criteria:

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

Procedure:

1. Open the cad model in ANSA V19.1.2 using the file>open option.
3. Refine the model using the length option under perimeters in the Mesh module. This will help to visualize the features in the model more properly. After refining the model perform a topo operation on the whole cad to stitch the closeby single cons together.
4. Perform a geometry check using the checks option to find any existing geometric errors. All the geometric errors need to be cleared before moving forward to the next stage, which is the mid-surface generation.
5. After clearing the geometric errors, perform the check again to confirm.
6. Now that all the errors have been cleared, we can start generating the mid-surface for each of the components of the assembly. Measure the thickness at all regions for placing the mid-surface at the correct distance. The components are found to be of uniform thickness, thus, we can use the skin option also to generate the mid-surfaces automatically.
7. After generating all the mid-surfaces, the next step is meshing. Prior to meshing, define the required quality criteria.
8. Mesh all the mid-surfaces to qualify the quality criteria and confirm the same by viewing the model in hidden mode. Make sure to create a zone cut around all bolt holes. Do not forget to apply thickness.
9. Release the mesh from the geometry and implement the necessary connections to assemble the CCB properly. Use seam weld to connect the components together.
10. To connect using seam weld, first, make a curve using the cons to curve option at the edge where seam weld has to be realized. Then convert this curve into a seam line and define the connection using the connection manager. While defining the connection, make sure to select the joining parts properly. Select the type of connection as an overlap shell or a y-joint shell depending on whether the joining edge is parallel to the surface or making some angle with the surface. After entering the required details for connection, implement the connection by clicking of apply and realize.
11. Similarly, at all the bolted joins, connect using bolt connection. After all the connections are made check the assembly carefully for any missed out component and do the needful.

Result:

1. The geometry was cleaned and mid-surface was generated.
2. The mid-surfaces were meshed and thickness was applied.
3. The CCB model was assembled using seam weld and bolt connections on the FE.

Learning outcomes:

1. Assembly of a model using connections.
2. The problems encountered.
3. Deciding the type of connection properly.