- displacementsThe displacements appropriate for the simulation geometry and coordinate system
C++ Type:std::vector<VariableName>
Controllable:No
Description:The displacements appropriate for the simulation geometry and coordinate system
- yield_stressYield stress after which plastic strain starts accumulating
C++ Type:double
Controllable:No
Description:Yield stress after which plastic strain starts accumulating
Plastic Truss
Computes the stress and strain for a truss element with plastic behavior defined by either linear hardening or a user-defined hardening function.
Description
The PlasticTruss model implements J2 plasticity for 1D truss elements. The axial elongation of the element is obtained from where is the total stretch computed from the updated length and the old length of the truss element. In case of linear elastic material, the axial stress is computed as Here, the nonlinear behavior of the truss is implemented using a simple J2 plasticity model that can use either simple linear hardening or a user-defined function to define the hardening behavior. The strain increment is obtained from the total stretch update The trial stress is estimated as
The yield condition is determined as where is the Young's modulus, is the hardening function and is the yield stress. When the trial stress is outside of the yield envelop the stresses are brought down using the iterative Newton method. In the case of linear hardening, the hardening function is defined as with being the hardening constant. In this case, the hardening variable at the beginning of the iterative process is obtained as The plastic strain increment is computed as The plastic strain for the next iteration is updated The iterative process continues until the updated stress lies on the yield curve. Then the elastic strain is updated as The updated axial stress is calculated
Example Input Syntax
[./truss]
type = PlasticTruss
youngs_modulus = 2.0e11
yield_stress = 500e5
outputs = 'exodus'
output_properties = 'elastic_stretch hardening_variable plastic_stretch total_stretch'
[../]
Input Parameters
- absolute_tolerance1e-10Absolute convergence tolerance for Newton iteration
Default:1e-10
C++ Type:double
Controllable:No
Description:Absolute convergence tolerance for Newton iteration
- base_nameOptional parameter that allows the user to define multiple mechanics material systems on the same block, i.e. for multiple phases
C++ Type:std::string
Controllable:No
Description:Optional parameter that allows the user to define multiple mechanics material systems on the same block, i.e. for multiple phases
- blockThe list of blocks (ids or names) that this object will be applied
C++ Type:std::vector<SubdomainName>
Controllable:No
Description:The list of blocks (ids or names) that this object will be applied
- boundaryThe list of boundaries (ids or names) from the mesh where this object applies
C++ Type:std::vector<BoundaryName>
Controllable:No
Description:The list of boundaries (ids or names) from the mesh where this object applies
- computeTrueWhen false, MOOSE will not call compute methods on this material. The user must call computeProperties() after retrieving the MaterialBase via MaterialBasePropertyInterface::getMaterialBase(). Non-computed MaterialBases are not sorted for dependencies.
Default:True
C++ Type:bool
Controllable:No
Description:When false, MOOSE will not call compute methods on this material. The user must call computeProperties() after retrieving the MaterialBase via MaterialBasePropertyInterface::getMaterialBase(). Non-computed MaterialBases are not sorted for dependencies.
- constant_onNONEWhen ELEMENT, MOOSE will only call computeQpProperties() for the 0th quadrature point, and then copy that value to the other qps.When SUBDOMAIN, MOOSE will only call computeQpProperties() for the 0th quadrature point, and then copy that value to the other qps. Evaluations on element qps will be skipped
Default:NONE
C++ Type:MooseEnum
Controllable:No
Description:When ELEMENT, MOOSE will only call computeQpProperties() for the 0th quadrature point, and then copy that value to the other qps.When SUBDOMAIN, MOOSE will only call computeQpProperties() for the 0th quadrature point, and then copy that value to the other qps. Evaluations on element qps will be skipped
- declare_suffixAn optional suffix parameter that can be appended to any declared properties. The suffix will be prepended with a '_' character.
C++ Type:MaterialPropertyName
Controllable:No
Description:An optional suffix parameter that can be appended to any declared properties. The suffix will be prepended with a '_' character.
- hardening_constant0Hardening slope
Default:0
C++ Type:double
Controllable:No
Description:Hardening slope
- hardening_functionEngineering stress as a function of plastic strain
C++ Type:FunctionName
Controllable:No
Description:Engineering stress as a function of plastic strain
- prop_getter_suffixAn optional suffix parameter that can be appended to any attempt to retrieve/get material properties. The suffix will be prepended with a '_' character.
C++ Type:MaterialPropertyName
Controllable:No
Description:An optional suffix parameter that can be appended to any attempt to retrieve/get material properties. The suffix will be prepended with a '_' character.
- relative_tolerance1e-08Relative convergence tolerance for Newton iteration
Default:1e-08
C++ Type:double
Controllable:No
Description:Relative convergence tolerance for Newton iteration
- temperature273.0Temperature in Kelvin
Default:273.0
C++ Type:std::vector<VariableName>
Controllable:No
Description:Temperature in Kelvin
- temperature_ref273Reference temperature for thermal expansion in K
Default:273
C++ Type:double
Controllable:No
Description:Reference temperature for thermal expansion in K
- thermal_expansion_coeff0Thermal expansion coefficient in 1/K
Default:0
C++ Type:double
Controllable:No
Description:Thermal expansion coefficient in 1/K
- youngs_modulusVariable containing Young's modulus
C++ Type:std::vector<VariableName>
Controllable:No
Description:Variable containing Young's modulus
Optional Parameters
- control_tagsAdds user-defined labels for accessing object parameters via control logic.
C++ Type:std::vector<std::string>
Controllable:No
Description:Adds user-defined labels for accessing object parameters via control logic.
- enableTrueSet the enabled status of the MooseObject.
Default:True
C++ Type:bool
Controllable:Yes
Description:Set the enabled status of the MooseObject.
- implicitTrueDetermines whether this object is calculated using an implicit or explicit form
Default:True
C++ Type:bool
Controllable:No
Description:Determines whether this object is calculated using an implicit or explicit form
- seed0The seed for the master random number generator
Default:0
C++ Type:unsigned int
Controllable:No
Description:The seed for the master random number generator
- use_displaced_meshFalseWhether or not this object should use the displaced mesh for computation. Note that in the case this is true but no displacements are provided in the Mesh block the undisplaced mesh will still be used.
Default:False
C++ Type:bool
Controllable:No
Description:Whether or not this object should use the displaced mesh for computation. Note that in the case this is true but no displacements are provided in the Mesh block the undisplaced mesh will still be used.
Advanced Parameters
- output_propertiesList of material properties, from this material, to output (outputs must also be defined to an output type)
C++ Type:std::vector<std::string>
Controllable:No
Description:List of material properties, from this material, to output (outputs must also be defined to an output type)
- outputsnone Vector of output names where you would like to restrict the output of variables(s) associated with this object
Default:none
C++ Type:std::vector<OutputName>
Controllable:No
Description:Vector of output names where you would like to restrict the output of variables(s) associated with this object