j integral and stress intensity factor relation

Hi,

Dear all,

We all know that J can be calculated by J=1/E(KI^2+KII^2).

but how to calculate the KI and KII from J.

I facing this pronlem as Abaqus can only calculated J integral for epfm, but I need the KI and KII as I only got K threshold and KIC for the material.

 Thank You

Haidir