4. Standardization of the refund rate G

4.1. 2D plane stresses and plane deformations

In dimension 2 (plane stresses and plane deformations), the crack bottom is reduced to one point and the value \(G(\theta )\) from the CALC_G command is independent of the choice of field \(\theta\):

\(G=G(\theta )\forall \theta \in \Theta\)

4.2. Model symmetry

If we only model half of the solid in relation to the crack:

• or specify the keyword SYME =” OUI “in the commands concerned;

or do not forget to multiply by 2, the values of the energy recovery rate :math:`G` or :math:`G(s)` and by 4 those of :math:`{G}_{mathrm{Irwin}}`.* In addition, the values of the stress intensity factors corresponding to the mode of symmetry must also be multiplied by 2.