Performed Batch meshing for a 'car hood assembly' using HYPERMESH

AIM

To Perform Batch-meshing on the given components (Fender & Hood assembly - BIW component) with the given criteria and assign the non-linear material property Steel for Radioss profile to them.

GIVEN DATA

1. CAD Model.
2. Quality Criteria.
3. Parametric file.

1. CAD MODEL:

Here the given cad model are BIW Components,

• Fender
• Hood Assembly

Figure 1. CAD MODEL - Given data

2. QUALITY CRITERIA:

Target Element Length = 5 Units

S.N	Quality Criteria	Value
1	Aspect Ratio	5
2	Skewness	45
3	Warping	15
4	Taper	0.5
5	Min. Length	2 Units
6	Max. Length	8 Units
7	Min angle Quad	45
8	Max angle Quad	135
9	Min angle Tria	20
10	Max angle Tria	120
10	Tria %	10

Table 1. Quality Criteria

3. Parametric File:

“Crash 5mm” parametric file

THEORY - BATCH MESH:

• Batch mesh ia a automated mesh where time generated to mesh is less while compared to traditional automesh.
• For large and assemblies batch mesh can be performed and its a role of CAE engineers to cross check the captured feature with cad model.
• If wrongly captured of feature has been found CAE engineer must make changes manually.
• Also it is an engineers role to clear the tria concentrations & to eliminate the quality failure if found.
• Also the mesh flow must be done manually in some areas.
• Batch mesh will generate both mid surface as well as mesh.

PROCEDURE:

BATCH MESH

Step 1: Import CAD model

Figure 1. CAD MODEL - import data

Step 2: Duplicate the Cad component - As the batch mesh deletes the original cad surfaces and gives only the mid surfaces & mesh duplicating the cad component will help us to cross check the original CAD withthe mid surfaces.

Step 3: Batch Mesh - Go to 2D --> Automesh ---> Batch mesh ---> Import the Parametric file & Criteria file ---> Mesh.

• “Crash 5mm” parametric file is used for this project.
• Criteria file should be set by Go to ---> preferences ---> Criteria file settings ---> Change the given criteria ---> Save. This saved file will be importing in criteria file setting while batch meshing.
• MID SURFACE & MESHING will be automatically generated once after performing batch mesh directly on the cad.

Figure 2. Batch Mesh

Step 3:

• To Cross check the mid surface, if there is any collapsed mid and meshes have to work on it manually.
• To eliminate the failed quality element.
• To eliminate more tria concentration.

ASSIGNING THE NON-LINEAR MATERIAL PROPERTY FOR RADIOSS PROFILE

Step 1: Create Material -

• Here the material created was steel and the card image for non-linear material is M2_PLAS_JOHNS_ZERIL
• The value of Initial density, Youngs modulus, poissons ratio, Yield stress, Hardening parameter, hardening exponent, Failure plastic strain, Maxium strees has been entered.
• The material tab has been shown in the below figure,

Step 2: Create Property -

• Here I have created two different property as Inner & outer panel thickness are 0.75mm & the thickness of Latch & Hinges are 1.2mm
• Shell thickness, No. of integration points through thickness, etc. has been given as shown in the below figure.

Figure 3. Material & Property Tab

Figure 4. Colour differentiation 'BY PROPERTY'

Step 3: Assigning the created property & material to the respective components -

• Here the created property & material has been assigned to the respective components.

Figure 5. Assign to component

COMPARISON BETWEEN TRADITIONAL Vs BATCH MESH

• Here the hood inner panel is compared between batch mesh and Traditional automesh.
• By refering the below figure, We can find the difference between the Qualiy of the mesh, Mesh flow, Capturing the feature element,etc.

Figure 6. COMPARISON - BATCH MESH Vs TRADITIONAL AUTO MESH (Tria Concentration)

Figure 7. COMPARISON - BATCH MESH Vs TRADITIONAL AUTO MESH (Hole Capture)

Figure 8. COMPARISON - BATCH MESH Vs TRADITIONAL AUTO MESH (Feature Capture)

CONCLUSION

Hence the Batch-meshing on the given components (Fender & Hood assembly - BIW component) with the given criteria has performed sucessfully and also the non-linear material property Steel for Radioss profile as assigned sucessfully to the components as per objective. Also the batch mesh & Traditional automesh has been compared by attatching some figures.

Figure 9. BATCH MESH

LEARNING OUTCOMES

At the end of this challenge, I can able to

Identify the suitable methods of mid surface extraction & mesh generation for a given component by considering the project time, Component complexity, etc