Online Training Session Day One

Overview

• Topic: Theory of FM and CA (Finite Element Method and Computer-Aided Engineering)
• Reference Book: Practical Aspects of Finite Element Simulation Student Guide
• Training Schedule: 10 days covering different aspects of FM and CA

Training Schedule

1. Day 1: Theory of FM
2. Day 2: 1D Meshing
3. Day 3: 2D Meshing
4. Day 4: 3D Meshing
5. Day 5: Different Analysis and Postprocessing
6. Day 6: Topology Optimization
7. Day 7: Topography Optimization
8. Day 8: Size Optimization
9. Day 9: Shape Optimization
10. Day 10: Composite Optimization

Software Covered

• HyperMesh
• Radioss and OptiStruct
• HyperView

Today's Topic: Introduction to Meshing

Introduction to Meshing

• Why do we carry out meshing?

  • To make calculations at a limited number of points and interpolate results for the entire domain
  • Reduces infinite degrees of freedom to finite degrees via discretization (meshing)

• Types of Elements:

  • 1D Elements: Rod, bar, beam, pipe, axisymmetric shell (Applications: long shafts, beams, pin joints)
  • 2D Elements: Shell, membrane, planar stress (Applications: sheet metal parts, plastic components)
  • 3D Elements: Tetra, penta, hexa (Applications: transmission casing, engine block)
  • Other Elements: Mass, spring, damper, rigid elements, weld elements

• Deciding the Element Type

  1. Geometry size and shape
     • 1D: One dimension much larger
     • 2D: Two dimensions much larger
     • 3D: All dimensions comparable
  2. Type of analysis needed
  3. Time allotted for the project

Detailed Meshing Process and Theory

• How to start meshing: Study the geometry, estimate time, check for symmetry
• Critical Areas: High-stress locations should have dense meshing and structured mesh
• Rules for 2D and 3D Meshing:
  • Avoid back-to-back triangles
  • Avoid mesh transition on curvatures
  • Avoid Tri elements on outer edges or holes
  • Minimum 2 elements across thickness for brick mesh
  • Ensuring all nodes lie on the surface correctly
• Element Quality Checks:
  • 2D Checks: Skewness, aspect ratio, warpage, Jacobian, included angles
  • 3D Checks: Tetra collapse, Jacobian, consistent shell normals
• Other Quality Checks: Free edges, duplicate elements, geometry deviation

Meshing in HyperMesh

• 1D Meshing

  • Types: Rod, bar, beam, pipe, axisymmetric shell
  • When to use and practical applications

• 2D Meshing

  • Types: Shell, membrane, planar stress
  • Mid-surface meshing: Necessary to represent the geometry correctly

• 3D Meshing

  • Types: Tetra, penta, hexa
  • Practical applications and issues with solid elements

• Element Quality Checks

  • Importance: Ensure the accuracy and stability of the simulation
  • Parameters: Skew, aspect ratio, warpage, Jacobian, included angles

Material and Property Information

• Material Classification

  • Isotropic: Properties independent of direction
  • Orthotropic: Different properties in three directions
  • Anisotropic: Different properties in crystalographic planes
  • Laminates: Multiple materials bound in layers

• Material Properties: Modulus of elasticity, Poisson's ratio, density, yield strength, ultimate strength

Conclusion

• For a free e-copy of the referenced book, visit: Student Guide Request
• Provide feedback to improve the training: edusupport@india.ala.com