Project - 2 - Meshing on the suspension Assembly

Project 2: Meshing on the suspension Assembly

Aim: Checking the given Suspension model for geometrical errors and mid surface extraction for component with uniform thickness components and tetra meshing of the other components with the given mesh quality criteria in addition to connections.

Given model: Suspension model

Parts include in the model:

1.

2.

3.

4.

5.

6.

7.

8.

9.

10.

11.

12.

13.

14.

15.

16.

17.

18.

19.

20. Tyre

21. Rim

Given mid surface mesh Quality criteria for components with uniform thickness less than 5mm (Mixed Elements):

S.No	Quality Criteria	Value
1	Target/Average length	4
2	Minimum Length	2
3	Maximum Length	6
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

Given surface mesh Quality criteria for Tyre and Rim components (Tria Elements):

S.No	Quality Criteria	Value
1	Target/Average length	6.5
2	Minimum Length	5
3	Maximum Length	10
4	Skewness	45

Given Surface mesh Quality criteria for components with Nom-uniform thickness other than Tyre and Rim (Tria Elements):

S.No	Quality Criteria	Value
1	Target/Average length	4
2	Minimum Length	2
3	Maximum Length	6
4	Skewness	45

Given Volume mesh Quality criteria for Non Uniform Components (Tetra Element):

S.No	Quality Criteria	Value
1	Tet Collapse	0.2

Procedure steps followed:

1. Checking for Geometrical errors and fixing them for all different components
2. Meshing Component 1 using beam element
3. Extraction of Mid Surface of sub assembly Component 2 and meshing using Batch mesh
4. Surface Meshing of other components using Batch mesh for given quality criteria
5. Deploying Seam weld and bolt connections between components
6. Define volumes for seperate non uniform parts
7. Solid meshing using unstructured (tetra) mesh for all the volumes
8. Assigning thickness to mid surface meshed sub Assembly component 2

Procedure:

1. Checking for Geometrical errors and fixing them for all different components

   After importing the given model into ANSA, checking for geometry cleanup is done from

   Tools -> Checks -> Geometry

   Before Executing Geometry check After Executing Geometry check

   

   After Geometry cleanup

   

   These errors are solved by Auto fixing them through clicking on actions icon -> Fix

2. Meshing Component 1 using beam element.

   The component 1 is a spring part and this is modeled and meshed using 1D beam element

   This is done by forming middle curve which follows profile of the spring by using

   TOPO -> Curves -> Middle

   

   Then using Nastran Deck -> Elements -> CBEAM and Selecting the curve and On COG point of curve by checking "Orientation with node" and using Curve (box)

   specifying the element length and assigning a different PBEAM PID and confirming it.

   

   Assigning A(A) by using '?' and giving the radius from the model

   By Confirming the PID and selecting the direction from

   Changing orient to 'With node Z- axis'.

   

   1D beam elements are created.

3. Extraction of Mid Surface of sub assembly Component 2 and meshing using Batch mesh

   The component 2 has uniform thickness and is less than 5 mm. So we extract mid surface using

   TOPO -> Faces -> Offset and selecting faces and confirming the offset distance which is half of the exact thickness of the component.

   The mid surface extracted is shown below

   Extending surfaces to intersect as to appear similar to model given.

   Meshing of theses components is done using Batch Mesh and Selecting contents using PIDs and editing Quality criteria as given and the meshing parameters as mixed elements.

   The meshed mid surface is shown below.

   

4. Surface Meshing of Component 3 to 19 using Batch mesh for given quality criteria

   The components other than above components are having non-uniform thickness and is greater than 5mm. For these kind of components we go for solid meshing and for solid meshing surface meshing is to be done. This done using Batch meshing.

   The qulality criteria and mesh parameters are different for tyre, rim and other components and so we use different meshing scenes for different quality criteria.

   So the given criteria are updated with the given values and meshing is run.

   The meshed models with assembly are shown below.

   

   Since the given component is only half of the suspension model we use symmetry option from Transform -> Copy and selecting the half of the suspension model along with mid surface component and 1D beam element to complete the other half which deleting the overlapping surfaces.

   
   The complete surface meshed model is shown below.
5. Deploying Seam weld and bolt connections between components

   After the surface meshing is done th connections are deployed.

   Here we use seam weld connection in components 2.

   This is done by TOPO -> CONS2Curve by creating a curve at the edge and converting to seam line.

   By projecting the perimeter onto curves surface the creation of wel is done by minimla disturbace to the base mesh by Mesh -> Shell mesh -> Project

   By Using connection manager the overlap shell is realized between the two different PIDs

   

   The bolt connection between other components are done using

   Nastran -> Elements -> RBE2 -> Many nodes and Two Nodes due to small mis alignment in CAD for the holes using

   The hole are selcted using Loop option and the BOLT connection is used for between Top and Bottom surface nodes.

   The model using connection is shown below.
6. Define volumes for seperate non uniform parts

   After surface meshing and connections are done we go for Volume meshing for NOn-uniform components using

   Volume Mesh -> Volume -> Define

   

   This defining volume can be done individually by changing detect on from 'whole db' to 'visible' or 'selected'.

   ANSA detects the volume and after that

   New PID for volumes are assigned.

   

7. Solid meshing using unstructured (tetra) mesh for all the volumes

   Meshing using Tetra Rapid is done.

   The volumetric tertra mesh is shown above.

8. Assigning thickness to mid surface meshed sub Assembly component 2

   After volume meshing assigning of thickness to mid surface is done in property dialog box. By double clicking on the PID

   Changing the value of T to the thickness value.

   The draw shell as solid is switched on to view thickness.

Learning Outcomes:

• Cleaning of Geometry.
• Meshing of component using Spot mesh Algorithm and Batch meshing and using different 2D elements (tria, Ortho/tria).
• Defining volumes and Unstructured Solid meshing.
• Deploying connections between different components

Conclusion:

Geometry cleanup, Mid surface extraction, Solid tetra meshing of given Suspension model is done using ANSA v22.0