Implements a boundary condition that enforces a displacement field around a crack tip based on applied stress intensity factors KI, KII, and KIII. More...

#include <InteractionIntegralBenchmarkBC.h>

Inheritance diagram for InteractionIntegralBenchmarkBC:

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Public Member Functions
	InteractionIntegralBenchmarkBC (const InputParameters &parameters)

Static Public Member Functions
static InputParameters	validParams ()

Protected Member Functions
virtual Real	computeQpValue ()
	Evaluate the function at the current quadrature point and timestep. More...

Protected Attributes
const int	_component

const CrackFrontDefinition *	_crack_front_definition

const unsigned int	_crack_front_point_index

Real	_r

Real	_theta

const Real	_poissons_ratio

const Real	_youngs_modulus

Real	_kappa

Real	_mu

const Function &	_ki_function

const Function &	_kii_function

const Function &	_kiii_function

Detailed Description

Implements a boundary condition that enforces a displacement field around a crack tip based on applied stress intensity factors KI, KII, and KIII.

This is used to test the interaction integral capability.

Definition at line 28 of file InteractionIntegralBenchmarkBC.h.

Constructor & Destructor Documentation

◆ InteractionIntegralBenchmarkBC()

InteractionIntegralBenchmarkBC::InteractionIntegralBenchmarkBC ( const InputParameters & parameters )

Definition at line 42 of file InteractionIntegralBenchmarkBC.C.

   : DirichletBCBase(parameters),
     _component(getParam<MooseEnum>("component")),
     _crack_front_definition(&getUserObject<CrackFrontDefinition>("crack_front_definition")),
     _crack_front_point_index(getParam<unsigned int>("crack_front_point_index")),
     _poissons_ratio(getParam<Real>("poissons_ratio")),
     _youngs_modulus(getParam<Real>("youngs_modulus")),
     _ki_function(getFunction("KI_function")),
     _kii_function(getFunction("KII_function")),
     _kiii_function(getFunction("KIII_function"))
 {
   _kappa = 3 - 4 * _poissons_ratio;
   _mu = _youngs_modulus / (2 * (1 + _poissons_ratio));
 }

Member Function Documentation

◆ computeQpValue()

Real InteractionIntegralBenchmarkBC::computeQpValue ( )

protectedvirtual

Evaluate the function at the current quadrature point and timestep.

Definition at line 58 of file InteractionIntegralBenchmarkBC.C.

 {
   const Real ki_val = _ki_function.value(_t, *_current_node);
   const Real kii_val = _kii_function.value(_t, *_current_node);
   const Real kiii_val = _kiii_function.value(_t, *_current_node);
  
   const Point p(*_current_node);
   _crack_front_definition->calculateRThetaToCrackFront(p, _crack_front_point_index, _r, _theta);
  
   if (_r == 0)
     _theta = 0;
  
   const Real st2 = std::sin(_theta / 2.0);
   const Real ct2 = std::cos(_theta / 2.0);
  
   Real disp(0.0);
  
   if (_component == 0)
     disp = 1 / (2 * _mu) * std::sqrt(_r / (2 * libMesh::pi)) *
            (ki_val * ct2 * (_kappa - 1 + 2 * st2 * st2) +
             kii_val * st2 * (_kappa + 1 + 2 * ct2 * ct2));
   else if (_component == 1)
     disp = 1 / (2 * _mu) * std::sqrt(_r / (2 * libMesh::pi)) *
            (ki_val * st2 * (_kappa + 1 - 2 * ct2 * ct2) -
             kii_val * ct2 * (_kappa - 1 - 2 * st2 * st2));
   else if (_component == 2)
     disp = 1 / _mu * std::sqrt(2 * _r / libMesh::pi) * kiii_val * st2;
  
   return disp;
 }

◆ validParams()

InputParameters InteractionIntegralBenchmarkBC::validParams ( )

static

Definition at line 18 of file InteractionIntegralBenchmarkBC.C.

 {
   MooseEnum disp_component("x=0 y=1 z=2");
   InputParameters params = DirichletBCBase::validParams();
   params.addClassDescription("Implements a boundary condition that enforces a displacement field "
                              "around a crack tip based on applied stress intensity factors.");
   params.addRequiredParam<MooseEnum>(
       "component", disp_component, "The component of the displacement to apply BC on.");
   params.addRequiredParam<UserObjectName>("crack_front_definition",
                                           "The CrackFrontDefinition user object name");
   params.addParam<unsigned int>(
       "crack_front_point_index", 0, "The index of the point on the crack front.");
   params.addRequiredParam<Real>("poissons_ratio", "Poisson's ratio for the material.");
   params.addRequiredParam<Real>("youngs_modulus", "Young's modulus of the material.");
   params.addRequiredParam<FunctionName>("KI_function",
                                         "Function describing the Mode I stress intensity factor.");
   params.addRequiredParam<FunctionName>("KII_function",
                                         "Function describing the Mode II stress intensity factor.");
   params.addRequiredParam<FunctionName>(
       "KIII_function", "Function describing the Mode III stress intensity factor.");
   params.set<bool>("preset") = true;
   return params;
 }