# GlobalStrain

Scalar Kernel to solve for the global strain

## Description

GlobalStrain solves the ODE equation setting the integral of the stress generated by applied load or volume change unrelated to deformation to zero. It stores the strain components into scalar variables of different order. Strain components calculated from this scalar kernel contributes towards the periodic strain. Combined with periodic displacements, this helps maintaining full strain periodicity.

It requires an input of the UserObject that calculates the integral value and corresponding jacobians.

Please refer to GlobalStrainUserObject for information about the residual and jacobian calculation.

## Example Input File Syntax

[./global_strain]
type = GlobalStrain
variable = global_strain
global_strain_uo = global_strain_uo
[../]

(modules/tensor_mechanics/test/tests/global_strain/global_strain.i)

## Input Parameters

• variableThe name of the variable that this kernel operates on

C++ Type:NonlinearVariableName

Options:

Description:The name of the variable that this kernel operates on

• global_strain_uoThe name of the GlobalStrainUserObject

C++ Type:UserObjectName

Options:

Description:The name of the GlobalStrainUserObject

### Required Parameters

• control_tagsAdds user-defined labels for accessing object parameters via control logic.

C++ Type:std::vector

Options:

Description:Adds user-defined labels for accessing object parameters via control logic.

• enableTrueSet the enabled status of the MooseObject.

Default:True

C++ Type:bool

Options:

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

Options:

Description:Determines whether this object is calculated using an implicit or explicit form

• 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

Options:

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.

• vector_tagsnontimeThe tag for the vectors this Kernel should fill

Default:nontime

C++ Type:MultiMooseEnum

Options:nontime time

Description:The tag for the vectors this Kernel should fill

• extra_vector_tagsThe extra tags for the vectors this Kernel should fill

C++ Type:std::vector

Options:

Description:The extra tags for the vectors this Kernel should fill

• matrix_tagssystemThe tag for the matrices this Kernel should fill

Default:system

C++ Type:MultiMooseEnum

Options:nontime system

Description:The tag for the matrices this Kernel should fill

• extra_matrix_tagsThe extra tags for the matrices this Kernel should fill

C++ Type:std::vector

Options:

Description:The extra tags for the matrices this Kernel should fill