Parameter Identification

Problem Description

The material parameters of a foam material must be determined from experimental results, namely the resultant reaction force exerted by a cubic sample on a rigid base.

prob_desc1.png

Fig. 1 – Foam material on rigid base

 

The ”experimental” resultant forces were generated from a LS-DYNA run with the parameters E=10⁶ and Y=10³. Samples are taken at different time steps :

Time [ms] Force [N]
2 10000
4 13000
6 15000
8 17000

New points illustrated by this example:

  • How to do parameter identification

    • using a point-based Mean Squared Error composite function.
    • using a history-based Mean Squared Error composite function.
  • Using multiple simulation models in the same optimization problem (multi-case).

Design Variables:

  • Young’s modulus E (YMod) of the foam material.
  • Yield stress Y (Yield) of the foam material.

Design formulation:

  • Minimize the residual reaction force (rcforce).

Possible approaches for the problem solution

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