Week 8 Challenge:3D tetra meshing CHALLENGE

Course: HyperMesh for FEA Plastics and Sheet Metal Applications

April 07, 2021

Submitted by: Amanpreet Singh Whan

Supervisor: David Nirmal Paul

List of Figures

Figure 1- Imported given CAD Models.

Figure 2-Patched up given CAD model.

Figure 3-Tetra Meshed given CAD Models.

Table of Contents

List of Figures.

1 Introduction.

2 Aims.

3 Methodology and Results.

3.1 Importing and Performing Geometry Clean-up of the CAD Models.

3.2 Tetra Meshing of the given CAD Models.

4 Conclusion.

1 Introduction

HyperMesh is the market-leading, multi-disciplinary finite element pre-processor which manages the generation of the largest, most complex models, starting with the import of CAD geometry to exporting a ready-to-run solver file. HyperMesh supports a wide variety of CAD and solver interfaces, making it a perfect solution for most industry verticals and domains. With its advanced geometry and meshing capabilities, HyperMesh provides an environment for rapid model generation. Generating high-quality mesh quickly is just one of Hyper Mesh’s core competencies. For complex sub-system generation and assembly, HyperMesh has advanced model assembly tools. Modeling of laminate composites is supported by advanced creation, editing, and visualization tools. Design changes can be made easily via mesh morphing and geometry dimensioning.

2 Aims

1. Check and fix all the geometry errors of the given Model for Geometry Clean-up purposes.
2. Set the element size and the type of mesh required.
3. Perform 3D or Solid Meshing of the components of the model as per the given Mesh Quality Criterion to generate an overall good mesh flow for the entire model.
4. Investigate and Improve the mesh quality wherever required.

3 Methodology and Results

The section describes the different stages that were performed using an engineering tool HyperWorks 2020 for the completion of the Week 8 Challenge task. These stages can be further broadly sub-categorized into three key steps, starting from importing of cad models to geometry clean-up and finally carry out Tetra meshing as per quality requirements for the given CAD models.

3.1 Importing and Performing Geometry Clean-up of the CAD Models

After opening the HyperWorks software, the first and foremost step is to import the given CAD models and then patch up any of the free edges present highlighted in red lines or cons for the geometric clean-up purposes.

3.2 Tetra Meshing of the given CAD Models

Meshing is a phase where the CAD geometry is discretized to represent the computational domain in which the solver will discover a solution. A refined mesh helps to achieve better results.

The meshing conducted for the given models is explained in the following steps:

• The target element size was set to 5 mm, 3mm, and 6mm respectively for the given CAD models. This will help to generate a mesh of constant element size.

• In the next step, the values of Quality Criteria and Mesh Parameters were entered as per challenge requirements to get a good flow of the mesh over the model. The values used for the quality criteria and mesh parameters are presented in the following tables.

Table 1-Quality criteria and their respective assigned values for Model 1.

Quality Criteria
Criteria	Value
Target size	5
Min length	2
Max length	7
Tet Collapse	0.15

Table 2- Quality criteria and their respective assigned values for Model 2.

Quality Criteria
Criteria	Value
Target size	3
Tet Collapse	0.15

Table 3- Quality criteria and their respective assigned values for Model 3.

Quality Criteria
Criteria	Value
Target size	4
Tet Collapse	0.15

• The ‘Auto Mesh’ command was used to produce 2D mesh for the models.

• Next, the tetra mesh was generated using ‘tetramesh’ command for the 2D meshed cad models.

• Tet collapse failing elements were fixed either using the ‘tetra remesh’ command or adjusting the height of the elements.

The results of the Tetra meshed CAD Models are presented in the following pictures.

4 Conclusion

In conclusion, the main aims of the Week 8 Challenge were to perform geometry clean-up and finally perform Tetra meshing as per given quality requirements. Tet Collapse errors were fixed either using the ‘tetra remesh’ command or by adjusting the heights of the tetra elements.