void
RCM2Material :: giveCrackedStiffnessMatrix(FloatMatrix &answer,
MatResponseMode rMode,
GaussPoint *gp,
TimeStep *atTime)
//
//
// Returns material incremental stiffness matrix for cracked concrete.
// This matrix is composed from submatrix, each of them corresponds to
// one active crack in material point.
// when constructing submatrix, following assumptions are made:
//
// A salient characteriastic of crack formation concerns the fact that in most general case
// of tree-dimensional solid only 3 out of 6 components of the crack strain rate vector
// are possibly non-zero.(the normal and two shear strain rates).
// We therefore assume that the stress-strain law for the crack has a structure
// such that the other strains rate components vanish. Moreover we assume that
// the novanishing strain rate components are only related to corresponding
// stress rate components (submatrix has dimensions 3x3).
//
// if strainIncrement is defined (not null) then we take care about possible unlo&reloading
// we don't teke care about possible cracking (or non-linear softening) during strain increment
// this correction is made in this -> updateCrackStatus (gp);
{
RCM2MaterialStatus *status = ( RCM2MaterialStatus * ) this->giveStatus(gp);
int i;
int numberOfActiveCracks = status->giveNumberOfTempActiveCracks();
IntArray crackMap;
status->giveCrackMap(crackMap);
if ( numberOfActiveCracks == 0 ) {
answer.resize(0, 0);
return;
}
answer.resize(3, 3);
answer.zero();
// loop over each active crack plane
for ( i = 1; i <= 3; i++ ) {
if ( crackMap.at(i) ) {
// obtain incremental law for one crack
answer.at(i, i) = this->giveCrackingModulus(rMode, gp,
status->giveCrackStrain(i),
i);
}
}
}
