double
RCSDEMaterial :: giveNormalCrackingStress(GaussPoint *gp, double crackStrain, int i)
//
// returns receivers Normal Stress in crack i for given cracking strain
//
{
double Gf, Ft, Le, answer, ef;
RCM2MaterialStatus *status = static_cast< RCM2MaterialStatus * >( this->giveStatus(gp) );
Le = status->giveCharLength(i);
Ft = this->computeStrength(gp, Le);
Gf = this->give(pscm_Gf, gp);
ef = Gf / ( Le * Ft );
if ( this->checkSizeLimit(gp, Le) ) {
if ( crackStrain >= status->giveTempMaxCrackStrain(i) ) {
// further softening
answer = Ft * exp(-crackStrain / ef);
} else {
// crack closing
// or unloading or reloading regime
answer = Ft * crackStrain / status->giveTempMaxCrackStrain(i) *
exp(-status->giveTempMaxCrackStrain(i) / ef);
}
} else {
answer = 0.;
}
return answer;
}
double
Concrete3 :: giveNormalCrackingStress(GaussPoint *gp, double crackStrain, int i)
//
// returns receivers Normal Stress in crack i for given cracking strain
//
{
double Cf, Ft, Gf, Le, answer, ef, minEffStrainForFullyOpenCrack;
RCM2MaterialStatus *status = static_cast< RCM2MaterialStatus * >( this->giveStatus(gp) );
minEffStrainForFullyOpenCrack = this->giveMinCrackStrainsForFullyOpenCrack(gp, i);
Cf = this->giveCrackingModulus(TangentStiffness, gp, crackStrain, i); // < 0
Le = status->giveCharLength(i);
Ft = this->computeStrength(gp, Le);
Gf = this->give(pscm_Gf, gp);
if ( this->checkSizeLimit(gp, Le) ) {
if ( softeningMode == linearSoftening ) {
if ( ( crackStrain >= minEffStrainForFullyOpenCrack ) ||
( status->giveTempMaxCrackStrain(i) >= minEffStrainForFullyOpenCrack ) ) {
// fully open crack - no stiffness
answer = 0.;
} else if ( crackStrain >= status->giveTempMaxCrackStrain(i) ) {
// further softening
answer = Ft + Cf * crackStrain;
} else if ( crackStrain <= 0. ) {
// crack closing
// no stress due to cracking
answer = 0.;
} else {
// unloading or reloading regime
answer = crackStrain * Ft *
( minEffStrainForFullyOpenCrack - status->giveTempMaxCrackStrain(i) ) /
( status->giveTempMaxCrackStrain(i) * minEffStrainForFullyOpenCrack );
}
} else { // Exponential softening
ef = Gf / ( Le * Ft );
if ( crackStrain >= status->giveTempMaxCrackStrain(i) ) {
// further softening
answer = Ft * exp(-crackStrain / ef);
} else {
// crack closing
// or unloading or reloading regime
answer = Ft * crackStrain / status->giveTempMaxCrackStrain(i) *
exp(-status->giveTempMaxCrackStrain(i) / ef);
}
}
} else {
answer = 0.;
}
return answer;
}
double
RCSDEMaterial :: giveCrackingModulus(MatResponseMode rMode, GaussPoint *gp,
double crackStrain, int i)
//
// returns current cracking modulus according to crackStrain for i-th
// crackplane
// now linear softening is implemented
// see also CreateStatus () function.
// softening modulus represents a relation between the normal crack strain
// rate and the normal stress rate.
//
{
// double Ee, Gf;
double Gf, Cf, Ft, Le, ef;
RCM2MaterialStatus *status = static_cast< RCM2MaterialStatus * >( this->giveStatus(gp) );
//
// now we have to set proper reduced strength and softening modulus Et
// in order to obtain energetically correct solution using the concept
// of fracture energy Gf, which is a material constant.
//
//Ee = this->give(pscm_Ee);
Gf = this->give(pscm_Gf, gp);
Le = status->giveCharLength(i);
Ft = this->computeStrength(gp, Le);
//minEffStrainForFullyOpenCrack = this->giveMinCrackStrainsForFullyOpenCrack(gp,i);
ef = Gf / ( Le * Ft );
if ( rMode == TangentStiffness ) {
if ( this->checkSizeLimit(gp, Le) ) {
if ( crackStrain >= status->giveTempMaxCrackStrain(i) ) {
// further softening
Cf = -Ft / ef *exp(-crackStrain / ef);
} else {
// unloading or reloading regime
Cf = Ft / status->giveTempMaxCrackStrain(i) * exp(-status->giveTempMaxCrackStrain(i) / ef);
}
} else {
Cf = 0.;
}
} else {
if ( this->checkSizeLimit(gp, Le) ) {
Cf = Ft / status->giveTempMaxCrackStrain(i) * exp(-status->giveTempMaxCrackStrain(i) / ef);
} else {
Cf = 0.;
}
}
return Cf;
}
double
RCSDMaterial :: giveMinCrackStrainsForFullyOpenCrack(GaussPoint *gp, int i)
//
// computes MinCrackStrainsForFullyOpenCrack for given gp and i-th crack
//
{
RCM2MaterialStatus *status = static_cast< RCM2MaterialStatus * >( this->giveStatus(gp) );
double Le, Gf, Ft;
Le = status->giveCharLength(i);
Gf = this->give(pscm_Gf, gp);
Ft = this->computeStrength(gp, Le);
return 2.0 * Gf / ( Le * Ft );
}
double
Concrete3 :: giveMinCrackStrainsForFullyOpenCrack(GaussPoint *gp, int i)
//
// computes MinCrackStrainsForFullyOpenCrack for given gp and i-th crack
//
{
if ( softeningMode == linearSoftening ) {
RCM2MaterialStatus *status = static_cast< RCM2MaterialStatus * >( this->giveStatus(gp) );
double Le, Gf, Ft;
Le = status->giveCharLength(i);
Gf = this->give(pscm_Gf, gp);
Ft = this->computeStrength(gp, Le);
return 2.0 * Gf / ( Le * Ft );
} else {
//return Gf/(Le*Ft); // Exponential softening
return 1.e6; // Exponential softening
}
}