Modelling and digital simulation of the structures fissured under residual stresses

Hi to all of you.I’m Tunisian student; I am preparing a project to obtain my diploma of mechanicsMy project is intituled:  “Modelling and digital simulation of the structures fissured under residual stresses”. So my first step is to understand the ability of ABAQUS 6.5 to simulate growth of crack and the limits of Abaqus in this subject.I met many problems: 

1) In ABAQUS 6.5, I have work with “fracture criteria” and “debond” options, is it the best way to attempt my object? 

2) Fracture criteria:  The critical stress and critical crack opening displacement  , their values that I must specified is it to be calculated from one of expression that define us in many books or for every materiel it has the value that we can to find it in references? 

3) Debond:  What is “Amplitude curve”, how can I define the value of this?Abaqus define this as follows:Data lines to define the debonding amplitude curve: First line:·         Time relative to the time at the start of debonding Relative amplitude of the stresses at the contact interface due to bonding remaining at this time. Etc., up to four time/amplitude pairs per line Etc., Repeat this data line as often as necessary to define the debonding amplitude curve.It looks that we know that is what will happen exactly!!!!!!!! 

4) For residual stresses,  I think to load the structure then to unload it, recover the values of the residual stresses and after regarding them as stress initial fields.My problem is: I can not calculate the contours integrals because in the theoric of Abaqus mention that:  

Initial stresses are not considered in the definition of contour integrals. Therefore, contour integral calculations for analyses including initial stresses in the regions used for the contour integral calculations will not be correct Ref: ABAQUS Analysis User's Manual   7.10.2 

5) The options “fracture criteria” and “debond”, I’m oblige to write the “file inp” after this I import it in Abaqus CAE, is it the only way?I tried to introduce them by making “edit keyword” but always it posts me that they are not put at the good emplacement.Please can you help me it is very urgent and important for me and temp presses me very much.

Thank’s for every thing