Tuesday, November 17, 2015

FEA : Finite element Analyis topology, shape optimization, adaptive analysis - Basics

Intelligent Tools

Finite element modeling requires some necessary decisions like selecting
  • Element type,
  • Mesh density
  • Applying Constrains, Restrains and loads 
Current generation Pre processing tools has several capabilities that intelligently guide us through the simulation process, and help us to get accurate / correct results.

Adaptive Analysis

One of such major intelligent tool is Adaptive analysis capability.
Adaptive analysis includes some primary decision parameters like number of elements required to accurately capture the desired performance measure.

  1. To capture displacements or Eigen values (resonant frequencies), generally a relatively coarse mesh will suffice.
  2. To study the stress results generally requires more elements and more attention to having elements in high stress regions.

Finite element mathematical formulations generally assume limited variation of stress across any one element. Adaptive analysis allows proper element density to be set automatically.

Simulation offers r (node position), h (element refinement and remeshing), and p-element adaptivity. A p-element tetrahedron has been implemented for linear statics analysis. The p-element implementation takes full advantage of the automatic meshing capability and geometry-based loads and boundary conditions. The combined r,h,p adaptive approach now available for solids leads to the most rapid solution convergence on problems with highest geometric complexity.


All processors like Hyperworks - Optistruct , NX Nastran, Solidworks  etc come up with optimization strategy which help us to design an cost effective, strength sufficient design .

Generally the Optimization module will provide the ability for analysis to directly guide design. It can help us rank possible design changes and understand the required magnitude of changes to achieve a particular goal.

  • Optimization allows you to effectively improve complex structures with interacting loads that cannot be handled with manual methods.
  • The geometry-based optimization capabilities work directly with the Modeler geometry. Allowable geometry changes are defined by selecting dimensions and entering variations in a form.

Design goals, as well as other constraints on deflection, stress, or natural frequency, are also entered through forms. As the design is updated through optimization iterations, the FE model (mesh, loads, and restraints) is updated automatically. Geometry updates maintain original design intent through the variational geometry constraint network defined during geometry construction. Modified versions of geometry are maintained through the data management capability.