Sunday, April 26, 2009

Few Tips On Mesh Refinement - How To Handle FEA Modeling Errors

“ Finite Element Analysis makes a good engineer great,and a bad engineer dangerous !”    I don't how many of you heard this saying, but certainly make sense rite. So where do you stand if you are thinking about Finite Element Analysis.

What is Finite Element Analysis or Modeling?

  • Analysis: A numerical method for approximation of a complex differential equation problem (discrete or continuous) into a finite number of solvable algebraic equations
  • Modeling: Subdividing a physical structure into a number of small (finite) entities (elements). This is followed by application of prescribed boundary conditions (loads and restraints)

What is needed to execute FE analysis?

  • Grasp of the problem area
  • Knowledge of the field (Structural, thermal, etc.)
  • Ability to solve a simplified version via analytical methods

The following slide will help you to understand about Mesh Refinement,Adaptive Meshing,Discretization Error,Convergence process, key things like:

h-refinement (changing the element size)
p-refinement (changing to higher order polynomial interpolations)
hp-refinement (combination of h and p refinements)
r-refinement (keep the number of nodes constant and adjust their positions)

Adaptive Finite Element Methods

Fundamental background in FE modeling and Analysis

  • Take formal training courses, not just vendor’s “how to” class.
  • Think about all the loading conditions that could affect the design, including thermal, mechanical, motion, etc.
  • Simplify CAD models to the minimum required detail.
  • Start with a simple model, and add complexity later.
  • Double check the input data (material and physical properties).
  • Examine the model with a range of boundary conditions instead of just one. Indicates design sensitivities!
  • Discuss the model and results with your colleagues.

My next topics will cover about Do's And Don't in FEA, How to find errors in finite-element models,DEFEATURING AND MESHING etc., So keep an eye on this guys..