Defining pre-existing Fracture as function of time and Position
 

Dear Foamers,

Using the basics model of Solid mechanics or Solids4Foam on FE4.0/4.1 for Solid Tutorials, on fractures, the pre-exisiting crack is predefined :

in the fvSolution file, we have :

crackLimitingBoxes
1(
(0 -1e-5 0)(0.06 1e-5 1) // -1e-5 ----- 1e5
);

and in the case file 0/U (D) for displacement, the crack is defined as :

crack
{
type solidCohesive;
relaxationFactor 0.01;
contact no;
penaltyScale 1;
frictionCoeff 0.1;
explicitSeparationDistance no;
value uniform ( 0 0 0 );
}


This assumes the crack height and width are fixed.

1. Please, how can I do to set the crack height/width as a function of time and position?

We have that G = - dΩ/ds , where :
Ω is the strain energy only affected by the change in fracture surface area: dΩ = (dΩ/ds)dΩ
G is the surface Energy release
s : crack surface area

in the file .....\src\solidModels\arbitraryCrack\solidCohesive \solidCohesiveFvPatchVectorField.C, the formula :

if ( ((currentGI_[i]/GIc[i]) + (currentGII_[i]/GIIc[i])) >= 1 )
{
//Pout << "GIc[i] is " << GIc[i] << ", curG is " << currentG << endl;
if (!cracked_[i])
{
Pout << "Face " << i << " is fully cracked" << endl;
}

cracked_[i] = true;

gives the condition criteria for propagation.

In the syntax below
if (dict.found("oldGI"))
{
oldGI_ = scalarField("oldGI", dict, p.size());
}
a declaration and definition of the variable oldGI ?

Or

In FE4.1/tut/solidMechanics/elasticAcpSolidFoam/crackingBiMatDcbDugdale/0 is it proper to define oldGI as follow:

crack
{
type solidCohesive;
relaxationFactor 0.01;
contact no;
penaltyScale 1;
frictionCoeff 0.1;
explicitSeparationDistance no;
oldGI 220; for instance
value uniform ( 0 0 0 );
}


2. Regarding the Surface Energy release, how can one record or extract the data file of Energy release variation w.r.t. crack surface area, to time, and Temperature as well in thermal stress is included?

Thank you.