ExponentialSoftening Class Reference

ExponentialSoftening is a smeared crack softening model that uses an exponential softening curve. More...

#include <ExponentialSoftening.h>

Inheritance diagram for ExponentialSoftening:

Public Member Functions
	ExponentialSoftening (const InputParameters &parameters)
virtual void	computeCrackingRelease (Real &stress, Real &stiffness_ratio, const Real strain, const Real crack_initiation_strain, const Real crack_max_strain, const Real cracking_stress, const Real youngs_modulus) override
	Compute the effect of the cracking release model on the stress and stiffness in the direction of a single crack. More...
void	resetQpProperties () final
	Retained as empty methods to avoid a warning from Material.C in framework. These methods are unused in all inheriting classes and should not be overwritten. More...
void	resetProperties () final

Static Public Member Functions
static InputParameters	validParams ()

Protected Attributes
const Real &	_residual_stress
	Residual stress after full softening. More...
const Real &	_alpha
	Initial slope of the softening curve. More...
const bool	_alpha_set_by_user
	Variable to track whether _alpha was set by the user. More...
const Real &	_beta
	Multiplier on alpha to determine the initial softening slope. More...

Detailed Description

ExponentialSoftening is a smeared crack softening model that uses an exponential softening curve.

It is for use with ComputeSmearedCrackingStress.

Definition at line 25 of file ExponentialSoftening.h.

Constructor & Destructor Documentation

ExponentialSoftening()

ExponentialSoftening::ExponentialSoftening

(

const InputParameters &

parameters

)

Definition at line 45 of file ExponentialSoftening.C.

  : SmearedCrackSofteningBase(parameters),
    _residual_stress(getParam<Real>("residual_stress")),
    _alpha(getParam<Real>("alpha")),
    _alpha_set_by_user(parameters.isParamSetByUser("alpha")),
    _beta(getParam<Real>("beta"))
{
}

Member Function Documentation

computeCrackingRelease()

void ExponentialSoftening::computeCrackingRelease ( Real &  stress, Real &  stiffness_ratio, const Real  strain, const Real  crack_initiation_strain, const Real  crack_max_strain, const Real  cracking_stress, const Real  youngs_modulus  )

overridevirtual

Compute the effect of the cracking release model on the stress and stiffness in the direction of a single crack.

Parameters

stress	Stress in direction of crack
stiffness_ratio	Ratio of damaged to original stiffness in cracking direction
strain	Strain in the current crack direction
crack_initiation_strain	Strain in crack direction when crack first initiated
crack_max_strain	Maximum strain in crack direction
cracking_stress	Threshold tensile stress for crack initiation
youngs_modulus	Young's modulus

Implements SmearedCrackSofteningBase.

Definition at line 55 of file ExponentialSoftening.C.

{
  mooseAssert(crack_max_strain >= crack_initiation_strain,
              "crack_max_strain must be >= crack_initiation_strain");
 
  Real alpha = 0.0;
  if (_alpha_set_by_user)
    alpha = _alpha;
  else
    alpha = -youngs_modulus;
 
  // Compute stress that follows exponental curve
  stress = cracking_stress *
           (_residual_stress +
            (1.0 - _residual_stress) * std::exp(alpha * _beta / cracking_stress *
                                                (crack_max_strain - crack_initiation_strain)));
  // Compute ratio of current stiffness to original stiffness
  stiffness_ratio = stress * crack_initiation_strain / (crack_max_strain * cracking_stress);
}

resetProperties()

void SmearedCrackSofteningBase::resetProperties ( )

inlinefinalinherited

Definition at line 58 of file SmearedCrackSofteningBase.h.

{}

resetQpProperties()

void SmearedCrackSofteningBase::resetQpProperties ( )

inlinefinalinherited

Retained as empty methods to avoid a warning from Material.C in framework. These methods are unused in all inheriting classes and should not be overwritten.

Definition at line 57 of file SmearedCrackSofteningBase.h.

{}

validParams()

InputParameters ExponentialSoftening::validParams ( )

static

Definition at line 19 of file ExponentialSoftening.C.

{
  InputParameters params = SmearedCrackSofteningBase::validParams();
  params.addClassDescription(
      "Softening model with an exponential softening response upon cracking. This "
      "class is intended to be used with ComputeSmearedCrackingStress.");
  params.addRangeCheckedParam<Real>(
      "residual_stress",
      0.0,
      "residual_stress <= 1 & residual_stress >= 0",
      "The fraction of the cracking stress allowed to be maintained following a crack.");
  params.addRangeCheckedParam<Real>(
      "alpha",
      -1.0,
      "alpha <= 0",
      "Initial slope of the exponential softening curve at crack initiation. "
      "If not specified, it is equal to the negative of the Young's modulus.");
  params.addRangeCheckedParam<Real>(
      "beta",
      1.0,
      "beta >= 0",
      "Multiplier applied to alpha to control the exponential softening "
      "behavior.");
  return params;
}

Member Data Documentation

_alpha

const Real& ExponentialSoftening::_alpha

protected

Initial slope of the softening curve.

Definition at line 45 of file ExponentialSoftening.h.

Referenced by computeCrackingRelease().

_alpha_set_by_user

const bool ExponentialSoftening::_alpha_set_by_user

protected

Variable to track whether _alpha was set by the user.

Definition at line 48 of file ExponentialSoftening.h.

Referenced by computeCrackingRelease().

_beta

const Real& ExponentialSoftening::_beta

protected

Multiplier on alpha to determine the initial softening slope.

Definition at line 51 of file ExponentialSoftening.h.

Referenced by computeCrackingRelease().

_residual_stress

const Real& ExponentialSoftening::_residual_stress

protected

Residual stress after full softening.

Definition at line 42 of file ExponentialSoftening.h.

Referenced by computeCrackingRelease().

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The documentation for this class was generated from the following files:

• tensor_mechanics/include/materials/ExponentialSoftening.h
• tensor_mechanics/src/materials/ExponentialSoftening.C