Hello SIMULIA community,

I have a question regarding the contour integral procedure. I know about 'Interaction Integrals' which is the technique ABAQUS uses to arrive at the Stress Intensity Factors (K's). 

ABAQUS doc states that 'This capability is available for isotropic and anisotropic materials’ when referring to interaction integrals . In this case the J-integrals calculated from the Ks will also be output. This is why we see two J-integral results:

If ABAQUS is outputting J value calculated from the Stress Intensity Factors (Ks), the equation for this must be provided in the Theory section or somewhere in the Doc. 

This is because, in the literature, you would know that different opinions exist about the auxiliary fields that must be used for anisotropic materials (in some case, E1/E2 ratio maybe 40 meaning a highly orthotropic material, or E1/E2 maybe 5, meaning a poor orthotropic material). How does ABAQUS know about these auxiliary fields for anisotropic materials as the E1/E2 ratio maybe anything).

So, a mention of the equation or the technique used to convert Ks to J must be provided (I guess ABAQUS does not use the isotropic relation equation) and has a dedicated anisotropic equation. 

Thank you in advance.

Best Regards,

Vishakh.