LS-DYNA

Seminar: Examination and evaluation of simulation in LS-DYNA

The detailed examination of numerical simulation is especially important in case of explicit time integration. Energy conservation, force equilibrium in contact, hourglass-stabilization, small penetrations as well as plausibility checks are only a view criteria to be named and have to be investigated by the user. What and how to check as well as the correct evaluation of results is the topic of this class. Based on examples the proceedure will be shown.

• Time-History Validation of Results
  • Energy conservation and energy ratio
  • Hourglass stabilization vs. internal energy
  • Mass scaling
  • Contact force equilibrium
  • Resultant and pair wise energies in contact
  • Equilibrium checks
  • Criteria for quasi-static simulations

• Contourplot Validation of Results
  • Deformation of parts and penetration
  • Fullfilment of contact
  • Spatial distribution of hourglass stabilitzation
  • Spatial distribution of mass scaling

• General Validation of Results
  • Message and d3hsp file with smallest timestep vs. mass scaling, surface timestep, warnings, initial penetrations
  • Specials in checking for quasi-static simulations
  • Usage of evaluation- and control tools of CADFEM (material check, mass check, ...

• Postprocessing
  • Contour plots for Gauß points
  • Shell normal and thickness appearance
  • smoothed vs. non-smoothed plot
  • Filtering of result curves
  • Identification of eigen frequencies and corresponding damping constant for damping
  • Forming limit diagrams
  • Combination of results as contour plot, superimposition of results
  • Result values local vs. global