THE VIRTUAL FIELDS METHOD
Association des Parents d'Elèves du Conservatoire de musique agréé et de danse de Châlons en Champagne

Application to elastoplasticity

The application of the virtual fields method to elasto-plastic constitutive equations is rather recent. The first efforts started in 2003. The main difference from elasticity is that the stresses cannot be written as an explicit function of the measured strains. Indeed, the measurements are total strains and it is therefore necessary to separate elastic from plastic strains. The principle of the method is therefore as follows:
Although also iterative, this procedure is much faster than finite element model updating since the calculation of the cost function does not require a complete finite element calculation but simply an extraction of elastic from total strains. The identification typically runs in a couple of minutes.
The following slideshow explains how the method works. The VFM in elasto-plasticity

References