- accelerationThe acceleration variable.
C++ Type:std::vector<VariableName>
Description:The acceleration variable.
- betabeta parameter for Newmark time integration.
C++ Type:double
Description:beta parameter for Newmark time integration.
- boundaryThe list of boundary IDs from the mesh where this boundary condition applies
C++ Type:std::vector<BoundaryName>
Description:The list of boundary IDs from the mesh where this boundary condition applies
- variableThe name of the variable that this residual object operates on
C++ Type:NonlinearVariableName
Description:The name of the variable that this residual object operates on
- velocityThe velocity variable.
C++ Type:std::vector<VariableName>
Description:The velocity variable.
PresetDisplacement
Prescribe the displacement on a given boundary in a given direction.
The PresetDisplacement class takes a displacement time history as input (provided using a function), differentiates it twice using backward Euler method to obtain the corresponding acceleration time history. This acceleration time history is then integrated using Newmark time integration method to obtain a modified displacement time history which is prescribed at the user provided boundary in the direction corresponding to the displacement variable provided as input. This modification in displacement time history ensures that there are no numerical errors in the acceleration or velocity response.
Input Parameters
- diag_save_inThe name of auxiliary variables to save this BC's diagonal jacobian contributions to. Everything about that variable must match everything about this variable (the type, what blocks it's on, etc.)
C++ Type:std::vector<AuxVariableName>
Options:
Description:The name of auxiliary variables to save this BC's diagonal jacobian contributions to. Everything about that variable must match everything about this variable (the type, what blocks it's on, etc.)
- displacementsThe displacements
C++ Type:std::vector<VariableName>
Options:
Description:The displacements
- function1Function describing the displacement.
Default:1
C++ Type:FunctionName
Options:
Description:Function describing the displacement.
- save_inThe name of auxiliary variables to save this BC's residual contributions to. Everything about that variable must match everything about this variable (the type, what blocks it's on, etc.)
C++ Type:std::vector<AuxVariableName>
Options:
Description:The name of auxiliary variables to save this BC's residual contributions to. Everything about that variable must match everything about this variable (the type, what blocks it's on, etc.)
- scale_factor1Scale factor if function is given.
Default:1
C++ Type:double
Options:
Description:Scale factor if function is given.
Optional Parameters
- control_tagsAdds user-defined labels for accessing object parameters via control logic.
C++ Type:std::vector<std::string>
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
- seed0The seed for the master random number generator
Default:0
C++ Type:unsigned int
Options:
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
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.
Advanced Parameters
- extra_matrix_tagsThe extra tags for the matrices this Kernel should fill
C++ Type:std::vector<TagName>
Options:
Description:The extra tags for the matrices this Kernel should fill
- extra_vector_tagsThe extra tags for the vectors this Kernel should fill
C++ Type:std::vector<TagName>
Options:
Description:The extra tags for the vectors this Kernel should fill
- matrix_tagssystem timeThe tag for the matrices this Kernel should fill
Default:system time
C++ Type:MultiMooseEnum
Options:nontime, system, time
Description:The tag for the matrices this Kernel should fill
- vector_tagsresidualThe tag for the vectors this Kernel should fill
Default:residual
C++ Type:MultiMooseEnum
Options:nontime, time, residual
Description:The tag for the vectors this Kernel should fill
Tagging Parameters
Input Files
- (modules/tensor_mechanics/test/tests/central_difference/lumped/3D/3d_nodalmass_implicit.i)
- (modules/tensor_mechanics/test/tests/central_difference/consistent/3D/3d_consistent_implicit.i)
- (modules/tensor_mechanics/test/tests/dynamics/prescribed_displacement/3D_QStatic_1_Ramped_Displacement_ti.i)
- (modules/tensor_mechanics/test/tests/central_difference/lumped/2D/2d_nodalmass_implicit.i)
- (modules/tensor_mechanics/test/tests/dynamics/prescribed_displacement/3D_QStatic_1_Ramped_Displacement_with_gravity.i)
- (modules/tensor_mechanics/test/tests/dynamics/prescribed_displacement/3D_QStatic_1_Ramped_Displacement.i)
- (modules/tensor_mechanics/test/tests/central_difference/consistent/2D/2d_consistent_implicit.i)
References
(modules/tensor_mechanics/test/tests/central_difference/lumped/3D/3d_nodalmass_implicit.i)
# Test for the Newmark-Beta time integrator
[Mesh]
[./generated_mesh]
type = GeneratedMeshGenerator
dim = 3
nx = 1
ny = 1
nz = 2
xmin = 0.0
xmax = 1
ymin = 0.0
ymax = 1
zmin = 0.0
zmax = 2
[../]
[./all_nodes]
type = BoundingBoxNodeSetGenerator
new_boundary = 'all'
input = 'generated_mesh'
top_right = '1 1 2'
bottom_left = '0 0 0'
[../]
[]
[Variables]
[./disp_x]
[../]
[./disp_y]
[../]
[./disp_z]
[../]
[]
[AuxVariables]
[./vel_x]
[../]
[./accel_x]
[../]
[./vel_y]
[../]
[./accel_y]
[../]
[./vel_z]
[../]
[./accel_z]
[../]
[]
[Kernels]
[./DynamicTensorMechanics]
displacements = 'disp_x disp_y disp_z'
[../]
[]
[AuxKernels]
[./accel_x]
type = TestNewmarkTI
variable = accel_x
displacement = disp_x
first = false
[../]
[./vel_x]
type = TestNewmarkTI
variable = vel_x
displacement = disp_x
[../]
[./accel_y]
type = TestNewmarkTI
variable = accel_y
displacement = disp_y
first = false
[../]
[./vel_y]
type = TestNewmarkTI
variable = vel_y
displacement = disp_y
[../]
[./accel_z]
type = TestNewmarkTI
variable = accel_z
displacement = disp_z
first = false
[../]
[./vel_z]
type = TestNewmarkTI
variable = vel_z
displacement = disp_z
[../]
[]
[BCs]
[./x_bot]
type = PresetDisplacement
boundary = 'back'
variable = disp_x
beta = 0.25
velocity = vel_x
acceleration = accel_x
function = dispx
[../]
[./y_bot]
type = PresetDisplacement
boundary = 'back'
variable = disp_y
beta = 0.25
velocity = vel_y
acceleration = accel_y
function = dispy
[../]
[./z_bot]
type = PresetDisplacement
boundary = 'back'
variable = disp_z
beta = 0.25
velocity = vel_z
acceleration = accel_z
function = dispz
[../]
[]
[Functions]
[./dispx]
type = PiecewiseLinear
x = '0.0 1.0 2.0 3.0 4.0' # time
y = '0.0 1.0 0.0 -1.0 0.0' # displacement
[../]
[./dispy]
type = ParsedFunction
value = 0.1*t*t*sin(10*t)
[../]
[./dispz]
type = ParsedFunction
value = 0.1*t*t*sin(20*t)
[../]
[]
[NodalKernels]
[./nodal_mass_x]
type = NodalTranslationalInertia
boundary = 'all'
nodal_mass_file = 'nodal_mass_file.csv'
variable = 'disp_x'
[../]
[./nodal_mass_y]
type = NodalTranslationalInertia
boundary = 'all'
nodal_mass_file = 'nodal_mass_file.csv'
variable = 'disp_y'
[../]
[./nodal_mass_z]
type = NodalTranslationalInertia
boundary = 'all'
nodal_mass_file = 'nodal_mass_file.csv'
variable = 'disp_z'
[../]
[]
[Materials]
[./elasticity_tensor_block]
type = ComputeIsotropicElasticityTensor
youngs_modulus = 1e6
poissons_ratio = 0.25
block = 0
[../]
[./strain_block]
type = ComputeIncrementalSmallStrain
block = 0
displacements = 'disp_x disp_y disp_z'
[../]
[./stress_block]
type = ComputeFiniteStrainElasticStress
block = 0
[../]
[]
[Preconditioning]
[./andy]
type = SMP
full = true
[../]
[]
[Executioner]
type = Transient
solve_type = NEWTON
nl_abs_tol = 1e-08
nl_rel_tol = 1e-08
timestep_tolerance = 1e-6
start_time = -0.01
end_time = 0.1
dt = 0.005
[./TimeIntegrator]
type = NewmarkBeta
beta = 0.25
gamma = 0.5
[../]
[]
[Postprocessors]
[./accel_10x]
type = NodalVariableValue
nodeid = 10
variable = accel_x
[../]
[]
[Outputs]
exodus = false
csv = true
[]
(modules/tensor_mechanics/test/tests/central_difference/consistent/3D/3d_consistent_implicit.i)
# One element test for the Newmark-Beta time integrator.
[Mesh]
type = GeneratedMesh # Can generate simple lines, rectangles and rectangular prisms
dim = 3 # Dimension of the mesh
nx = 1 # Number of elements in the x direction
ny = 1 # Number of elements in the y direction
nz = 2 # Number of elements in the z direction
xmin = 0.0
xmax = 1
ymin = 0.0
ymax = 1
zmin = 0.0
zmax = 2
[]
[Variables]
[./disp_x]
[../]
[./disp_y]
[../]
[./disp_z]
[../]
[]
[AuxVariables]
[./vel_x]
[../]
[./accel_x]
[../]
[./vel_y]
[../]
[./accel_y]
[../]
[./vel_z]
[../]
[./accel_z]
[../]
[]
[Kernels]
[./DynamicTensorMechanics]
displacements = 'disp_x disp_y disp_z'
[../]
[./inertia_x]
type = InertialForce
variable = disp_x
[../]
[./inertia_y]
type = InertialForce
variable = disp_y
[../]
[./inertia_z]
type = InertialForce
variable = disp_z
[../]
[]
[AuxKernels]
[./accel_x]
type = TestNewmarkTI
variable = accel_x
displacement = disp_x
first = false
[../]
[./vel_x]
type = TestNewmarkTI
variable = vel_x
displacement = disp_x
[../]
[./accel_y]
type = TestNewmarkTI
variable = accel_y
displacement = disp_y
first = false
[../]
[./vel_y]
type = TestNewmarkTI
variable = vel_y
displacement = disp_y
[../]
[./accel_z]
type = TestNewmarkTI
variable = accel_z
displacement = disp_z
first = false
[../]
[./vel_z]
type = TestNewmarkTI
variable = vel_z
displacement = disp_z
[../]
[]
[BCs]
[./x_bot]
type = PresetDisplacement
boundary = 'back'
variable = disp_x
beta = 0.25
velocity = vel_x
acceleration = accel_x
function = dispx
[../]
[./y_bot]
type = PresetDisplacement
boundary = 'back'
variable = disp_y
beta = 0.25
velocity = vel_y
acceleration = accel_y
function = dispy
[../]
[./z_bot]
type = PresetDisplacement
boundary = 'back'
variable = disp_z
beta = 0.25
velocity = vel_z
acceleration = accel_z
function = dispz
[../]
[./Periodic]
[./x_dir]
variable = 'disp_x disp_y disp_z'
primary = 'left'
secondary = 'right'
translation = '1.0 0.0 0.0'
[../]
[./y_dir]
variable = 'disp_x disp_y disp_z'
primary = 'bottom'
secondary = 'top'
translation = '0.0 1.0 0.0'
[../]
[../]
[]
[Functions]
[./dispx]
type = PiecewiseLinear
x = '0.0 1.0 2.0 3.0 4.0' # time
y = '0.0 1.0 0.0 -1.0 0.0' # displacement
[../]
[./dispy]
type = ParsedFunction
value = 0.1*t*t*sin(10*t)
[../]
[./dispz]
type = ParsedFunction
value = 0.1*t*t*sin(20*t)
[../]
[]
[Materials]
[./elasticity_tensor_block]
type = ComputeIsotropicElasticityTensor
youngs_modulus = 1e6
poissons_ratio = 0.25
block = 0
[../]
[./strain_block]
type = ComputeIncrementalSmallStrain
block = 0
displacements = 'disp_x disp_y disp_z'
[../]
[./stress_block]
type = ComputeFiniteStrainElasticStress
block = 0
[../]
[./density]
type = GenericConstantMaterial
block = 0
prop_names = density
prop_values = 1e4
[../]
[]
[Preconditioning]
[./andy]
type = SMP
full = true
[../]
[]
[Executioner]
type = Transient
solve_type = NEWTON
nl_abs_tol = 1e-08
nl_rel_tol = 1e-08
timestep_tolerance = 1e-6
start_time = -0.01
end_time = 0.1
dt = 0.005
[./TimeIntegrator]
type = NewmarkBeta
beta = 0.25
gamma = 0.5
[../]
[]
[Postprocessors]
[./accel_6x]
type = NodalVariableValue
nodeid = 6
variable = accel_x
[../]
[]
[Outputs]
exodus = false
csv = true
[]
(modules/tensor_mechanics/test/tests/dynamics/prescribed_displacement/3D_QStatic_1_Ramped_Displacement_ti.i)
# One 3D element under ramped displacement loading.
#
# loading:
# time : 0.0 0.1 0.2 0.3
# disp : 0.0 0.0 -0.01 -0.01
# This displacement loading is applied using the PresetDisplacement boundary condition.
# Here, the given displacement time history is converted to an acceleration
# time history using Backward Euler time differentiation. Then, the resulting
# acceleration is integrated using Newmark time integration to obtain a
# displacement time history which is then applied to the boundary.
# This is done because if the displacement is applied using Dirichlet BC, the
# resulting acceleration is very noisy.
# Boundaries:
# x = 0 left
# x = 1 right
# y = 0 bottom
# y = 1 top
# z = 0 back
# z = 1 front
# Result: The displacement at the top node in the z direction should match
# the prescribed displacement. Also, the z acceleration should
# be two triangular pulses, one peaking at 0.1 and another peaking at
# 0.2.
[Mesh]
type = GeneratedMesh
dim = 3 # Dimension of the mesh
nx = 1 # Number of elements in the x direction
ny = 1 # Number of elements in the y direction
nz = 1 # Number of elements in the z direction
xmin = 0.0
xmax = 1
ymin = 0.0
ymax = 1
zmin = 0.0
zmax = 1
allow_renumbering = false # So NodalVariableValue can index by id
[]
[Variables] # variables that are solved
[./disp_x]
[../]
[./disp_y]
[../]
[./disp_z]
[../]
[]
[AuxVariables] # variables that are calculated for output
[./accel_x]
[../]
[./vel_x]
[../]
[./accel_y]
[../]
[./vel_y]
[../]
[./accel_z]
[../]
[./vel_z]
[../]
[./stress_xx]
order = CONSTANT
family = MONOMIAL
[../]
[./strain_xx]
order = CONSTANT
family = MONOMIAL
[../]
[./stress_yy]
order = CONSTANT
family = MONOMIAL
[../]
[./strain_yy]
order = CONSTANT
family = MONOMIAL
[../]
[./stress_zz]
order = CONSTANT
family = MONOMIAL
[../]
[./strain_zz]
order = CONSTANT
family = MONOMIAL
[../]
[]
[Kernels]
[./DynamicTensorMechanics] # zeta*K*vel + K * disp
displacements = 'disp_x disp_y disp_z'
stiffness_damping_coefficient = 0.000025
[../]
[./inertia_x] # M*accel + eta*M*vel
type = InertialForce
variable = disp_x
eta = 19.63
[../]
[./inertia_y]
type = InertialForce
variable = disp_y
eta = 19.63
[../]
[./inertia_z]
type = InertialForce
variable = disp_z
eta = 19.63
[../]
[]
[AuxKernels]
[./accel_x] # These auxkernels are only to check output
type = TestNewmarkTI
displacement = disp_x
variable = accel_x
first = false
[../]
[./accel_y]
type = TestNewmarkTI
displacement = disp_y
variable = accel_y
first = false
[../]
[./accel_z]
type = TestNewmarkTI
displacement = disp_z
variable = accel_z
first = false
[../]
[./vel_x]
type = TestNewmarkTI
displacement = disp_x
variable = vel_x
[../]
[./vel_y]
type = TestNewmarkTI
displacement = disp_y
variable = vel_y
[../]
[./vel_z]
type = TestNewmarkTI
displacement = disp_z
variable = vel_z
[../]
[./stress_xx]
type = RankTwoAux
rank_two_tensor = stress
variable = stress_xx
index_i = 0
index_j = 0
[../]
[./strain_xx]
type = RankTwoAux
rank_two_tensor = total_strain
variable = strain_xx
index_i = 0
index_j = 0
[../]
[./stress_yy]
type = RankTwoAux
rank_two_tensor = stress
variable = stress_yy
index_i = 1
index_j = 1
[../]
[./strain_yy]
type = RankTwoAux
rank_two_tensor = total_strain
variable = strain_yy
index_i = 1
index_j = 1
[../]
[./stress_zz]
type = RankTwoAux
rank_two_tensor = stress
variable = stress_zz
index_i = 2
index_j = 2
[../]
[./strain_zz]
type = RankTwoAux
rank_two_tensor = total_strain
variable = strain_zz
index_i = 2
index_j = 2
[../]
[]
[Functions]
[./displacement_front]
type = PiecewiseLinear
data_file = 'displacement.csv'
format = columns
[../]
[]
[BCs]
[./Preset_displacement]
type = PresetDisplacement
variable = disp_z
function = displacement_front
boundary = front
beta = 0.25
velocity = vel_z
acceleration = accel_z
[../]
[./anchor_x]
type = DirichletBC
variable = disp_x
boundary = left
value = 0.0
[../]
[./anchor_y]
type = DirichletBC
variable = disp_y
boundary = bottom
value = 0.0
[../]
[./anchor_z]
type = DirichletBC
variable = disp_z
boundary = back
value = 0.0
[../]
[]
[Materials]
[./elasticity_tensor]
youngs_modulus = 325e6 #Pa
poissons_ratio = 0.3
type = ComputeIsotropicElasticityTensor
block = 0
[../]
[./strain]
#Computes the strain, assuming small strains
type = ComputeSmallStrain
block = 0
displacements = 'disp_x disp_y disp_z'
[../]
[./stress]
#Computes the stress, using linear elasticity
type = ComputeLinearElasticStress
block = 0
[../]
[./density]
type = GenericConstantMaterial
block = 0
prop_names = density
prop_values = 2000 #kg/m3
[../]
[]
[Executioner]
type = Transient
start_time = 0
end_time = 3.0
l_tol = 1e-6
nl_rel_tol = 1e-6
nl_abs_tol = 1e-6
dt = 0.1
timestep_tolerance = 1e-6
# Time integrator scheme
scheme = "newmark-beta"
[]
[Postprocessors] # These quantites are printed to a csv file at every time step
[./_dt]
type = TimestepSize
[../]
[./accel_6x]
type = NodalVariableValue
nodeid = 6
variable = accel_x
[../]
[./accel_6y]
type = NodalVariableValue
nodeid = 6
variable = accel_y
[../]
[./accel_6z]
type = NodalVariableValue
nodeid = 6
variable = accel_z
[../]
[./vel_6x]
type = NodalVariableValue
nodeid = 6
variable = vel_x
[../]
[./vel_6y]
type = NodalVariableValue
nodeid = 6
variable = vel_y
[../]
[./vel_6z]
type = NodalVariableValue
nodeid = 6
variable = vel_z
[../]
[./disp_6x]
type = NodalVariableValue
nodeid = 6
variable = disp_x
[../]
[./disp_6y]
type = NodalVariableValue
nodeid = 6
variable = disp_y
[../]
[./disp_6z]
type = NodalVariableValue
nodeid = 6
variable = disp_z
[../]
[]
[Outputs]
file_base = "3D_QStatic_1_Ramped_Displacement_out"
exodus = true
csv = true
perf_graph = true
[]
(modules/tensor_mechanics/test/tests/central_difference/lumped/2D/2d_nodalmass_implicit.i)
# One element test to test the central difference time integrator.
[Mesh]
[./generated_mesh]
type = GeneratedMeshGenerator
dim = 2
xmin = 0
xmax = 1
ymin = 0
ymax = 2
nx = 1
ny = 2
[../]
[./all_nodes]
type = BoundingBoxNodeSetGenerator
new_boundary = 'all'
input = 'generated_mesh'
top_right = '1 2 0'
bottom_left = '0 0 0'
[../]
[]
[Variables]
[./disp_x]
[../]
[./disp_y]
[../]
[]
[AuxVariables]
[./accel_x]
[../]
[./vel_x]
[../]
[./accel_y]
[../]
[./vel_y]
[../]
[]
[AuxKernels]
[./accel_x]
type = TestNewmarkTI
variable = accel_x
displacement = disp_x
first = false
[../]
[./vel_x]
type = TestNewmarkTI
variable = vel_x
displacement = disp_x
[../]
[./accel_y]
type = TestNewmarkTI
variable = accel_y
displacement = disp_y
first = false
[../]
[./vel_y]
type = TestNewmarkTI
variable = vel_y
displacement = disp_y
[../]
[]
[Kernels]
[./DynamicTensorMechanics]
displacements = 'disp_x disp_y'
[../]
[]
[BCs]
[./y_bot]
type = DirichletBC
variable = disp_y
boundary = bottom
value = 0.0
[../]
[./x_bot]
type = PresetDisplacement
boundary = bottom
variable = disp_x
beta = 0.25
velocity = vel_x
acceleration = accel_x
function = disp
[../]
[]
[Functions]
[./disp]
type = PiecewiseLinear
x = '0.0 1.0 2.0 3.0 4.0' # time
y = '0.0 1.0 0.0 -1.0 0.0' # displacement
[../]
[]
[NodalKernels]
[./nodal_mass_x]
type = NodalTranslationalInertia
variable = 'disp_x'
nodal_mass_file = 'nodal_mass_file.csv'
boundary = 'all'
[../]
[./nodal_mass_y]
type = NodalTranslationalInertia
variable = 'disp_y'
nodal_mass_file = 'nodal_mass_file.csv'
boundary = 'all'
[../]
[]
[Materials]
[./elasticity_tensor_block]
type = ComputeIsotropicElasticityTensor
youngs_modulus = 1e6
poissons_ratio = 0.25
block = 0
[../]
[./strain_block]
type = ComputeIncrementalSmallStrain
block = 0
displacements = 'disp_x disp_y'
[../]
[./stress_block]
type = ComputeFiniteStrainElasticStress
block = 0
[../]
[]
[Preconditioning]
[./andy]
type = SMP
full = true
[../]
[]
[Executioner]
type = Transient
solve_type = NEWTON
nl_abs_tol = 1e-11
nl_rel_tol = 1e-11
start_time = -0.01
end_time = 0.1
dt = 0.005
timestep_tolerance = 1e-6
[./TimeIntegrator]
type = NewmarkBeta
beta = 0.25
gamma = 0.5
[../]
[]
[Postprocessors]
[./accel_2x]
type = PointValue
point = '1.0 2.0 0.0'
variable = accel_x
[../]
[]
[Outputs]
exodus = false
csv = true
[]
(modules/tensor_mechanics/test/tests/dynamics/prescribed_displacement/3D_QStatic_1_Ramped_Displacement_with_gravity.i)
# One 3D element under ramped displacement loading.
#
# loading in z direction:
# time : 0.0 0.1 0.2 0.3
# disp : 0.0 0.0 -0.01 -0.01
# Gravity is applied in y direction. To equilibrate the system
# under gravity, a static analysis is run in the first time step
# by turning off the inertial terms. (see controls block and
# DynamicTensorMechanics block).
# Result: The displacement at the top node in the z direction should match
# the prescribed displacement. Also, the z acceleration should
# be two triangular pulses, one peaking at 0.1 and another peaking at
# 0.2.
# The y displacement would be offset by the gravity displacement.
# Also the y acceleration and velocity should be zero until the loading in
# the z direction starts (i.e, until 0.1s)
# Note: The time step used in the displacement data file should match
# the simulation time step (dt and dtmin in the Executioner block).
[Mesh]
type = GeneratedMesh
dim = 3 # Dimension of the mesh
nx = 1 # Number of elements in the x direction
ny = 1 # Number of elements in the y direction
nz = 1 # Number of elements in the z direction
xmin = 0.0
xmax = 1
ymin = 0.0
ymax = 1
zmin = 0.0
zmax = 1
allow_renumbering = false # So NodalVariableValue can index by id
[]
[Variables] # variables that are solved
[./disp_x]
[../]
[./disp_y]
[../]
[./disp_z]
[../]
[]
[AuxVariables] # variables that are calculated for output
[./accel_x]
[../]
[./vel_x]
[../]
[./accel_y]
[../]
[./vel_y]
[../]
[./accel_z]
[../]
[./vel_z]
[../]
[./stress_xx]
order = CONSTANT
family = MONOMIAL
[../]
[./strain_xx]
order = CONSTANT
family = MONOMIAL
[../]
[./stress_yy]
order = CONSTANT
family = MONOMIAL
[../]
[./strain_yy]
order = CONSTANT
family = MONOMIAL
[../]
[./stress_zz]
order = CONSTANT
family = MONOMIAL
[../]
[./strain_zz]
order = CONSTANT
family = MONOMIAL
[../]
[]
[Kernels]
[./DynamicTensorMechanics] # zeta*K*vel + K * disp
displacements = 'disp_x disp_y disp_z'
stiffness_damping_coefficient = 0.000025
static_initialization = true #turns off rayliegh damping for the first time step to stabilize system under gravity
[../]
[./inertia_x] # M*accel + eta*M*vel
type = InertialForce
variable = disp_x
velocity = vel_x
acceleration = accel_x
beta = 0.25 # Newmark time integration
gamma = 0.5 # Newmark time integration
eta = 19.63
[../]
[./inertia_y]
type = InertialForce
variable = disp_y
velocity = vel_y
acceleration = accel_y
beta = 0.25
gamma = 0.5
eta = 19.63
[../]
[./inertia_z]
type = InertialForce
variable = disp_z
velocity = vel_z
acceleration = accel_z
beta = 0.25
gamma = 0.5
eta = 19.63
[../]
[./gravity]
type = Gravity
variable = disp_y
value = -9.81
[../]
[]
[AuxKernels]
[./accel_x] # Calculates and stores acceleration at the end of time step
type = NewmarkAccelAux
variable = accel_x
displacement = disp_x
velocity = vel_x
beta = 0.25
execute_on = timestep_end
[../]
[./vel_x] # Calculates and stores velocity at the end of the time step
type = NewmarkVelAux
variable = vel_x
acceleration = accel_x
gamma = 0.5
execute_on = timestep_end
[../]
[./accel_y]
type = NewmarkAccelAux
variable = accel_y
displacement = disp_y
velocity = vel_y
beta = 0.25
execute_on = timestep_end
[../]
[./vel_y]
type = NewmarkVelAux
variable = vel_y
acceleration = accel_y
gamma = 0.5
execute_on = timestep_end
[../]
[./accel_z]
type = NewmarkAccelAux
variable = accel_z
displacement = disp_z
velocity = vel_z
beta = 0.25
execute_on = timestep_end
[../]
[./vel_z]
type = NewmarkVelAux
variable = vel_z
acceleration = accel_z
gamma = 0.5
execute_on = timestep_end
[../]
[./stress_xx]
type = RankTwoAux
rank_two_tensor = stress
variable = stress_xx
index_i = 0
index_j = 0
[../]
[./strain_xx]
type = RankTwoAux
rank_two_tensor = total_strain
variable = strain_xx
index_i = 0
index_j = 0
[../]
[./stress_yy]
type = RankTwoAux
rank_two_tensor = stress
variable = stress_yy
index_i = 1
index_j = 1
[../]
[./strain_yy]
type = RankTwoAux
rank_two_tensor = total_strain
variable = strain_yy
index_i = 1
index_j = 1
[../]
[./stress_zz]
type = RankTwoAux
rank_two_tensor = stress
variable = stress_zz
index_i = 2
index_j = 2
[../]
[./strain_zz]
type = RankTwoAux
rank_two_tensor = total_strain
variable = strain_zz
index_i = 2
index_j = 2
[../]
[]
[Functions]
[./displacement_front]
type = PiecewiseLinear
data_file = 'displacement.csv'
format = columns
[../]
[]
[BCs]
[./prescribed_displacement]
type = PresetDisplacement
variable = disp_z
velocity = vel_z
acceleration = accel_z
beta = 0.25
boundary = front
function = displacement_front
[../]
[./anchor_x]
type = DirichletBC
variable = disp_x
boundary = left
value = 0.0
[../]
[./anchor_y]
type = DirichletBC
variable = disp_y
boundary = bottom
value = 0.0
[../]
[./anchor_z]
type = DirichletBC
variable = disp_z
boundary = back
value = 0.0
[../]
[]
[Materials]
[./elasticity_tensor]
youngs_modulus = 325e6 #Pa
poissons_ratio = 0.3
type = ComputeIsotropicElasticityTensor
block = 0
[../]
[./strain]
#Computes the strain, assuming small strains
type = ComputeSmallStrain
block = 0
displacements = 'disp_x disp_y disp_z'
[../]
[./stress]
#Computes the stress, using linear elasticity
type = ComputeLinearElasticStress
block = 0
[../]
[./density]
type = GenericConstantMaterial
block = 0
prop_names = density
prop_values = 2000 #kg/m3
[../]
[]
[Controls] # turns off inertial terms for the first time step
[./period0]
type = TimePeriod
disable_objects = '*/vel_x */vel_y */vel_z */accel_x */accel_y */accel_z */inertia_x */inertia_y */inertia_z'
start_time = 0.0
end_time = 0.1 # dt used in the simulation
[../]
[../]
[Executioner]
type = Transient
start_time = 0
end_time = 3.0
l_tol = 1e-6
nl_rel_tol = 1e-6
nl_abs_tol = 1e-6
dt = 0.1
timestep_tolerance = 1e-6
[]
[Postprocessors] # These quantites are printed to a csv file at every time step
[./_dt]
type = TimestepSize
[../]
[./accel_6x]
type = NodalVariableValue
nodeid = 6
variable = accel_x
[../]
[./accel_6y]
type = NodalVariableValue
nodeid = 6
variable = accel_y
[../]
[./accel_6z]
type = NodalVariableValue
nodeid = 6
variable = accel_z
[../]
[./vel_6x]
type = NodalVariableValue
nodeid = 6
variable = vel_x
[../]
[./vel_6y]
type = NodalVariableValue
nodeid = 6
variable = vel_y
[../]
[./vel_6z]
type = NodalVariableValue
nodeid = 6
variable = vel_z
[../]
[./disp_6x]
type = NodalVariableValue
nodeid = 6
variable = disp_x
[../]
[./disp_6y]
type = NodalVariableValue
nodeid = 6
variable = disp_y
[../]
[./disp_6z]
type = NodalVariableValue
nodeid = 6
variable = disp_z
[../]
[]
[Outputs]
exodus = true
csv = true
perf_graph = true
[]
(modules/tensor_mechanics/test/tests/dynamics/prescribed_displacement/3D_QStatic_1_Ramped_Displacement.i)
# One 3D element under ramped displacement loading.
#
# loading:
# time : 0.0 0.1 0.2 0.3
# disp : 0.0 0.0 -0.01 -0.01
# This displacement loading is applied using the PresetDisplacement boundary condition.
# Here, the given displacement time history is converted to an acceleration
# time history using Backward Euler time differentiation. Then, the resulting
# acceleration is integrated using Newmark time integration to obtain a
# displacement time history which is then applied to the boundary.
# This is done because if the displacement is applied using Dirichlet BC, the
# resulting acceleration is very noisy.
# Boundaries:
# x = 0 left
# x = 1 right
# y = 0 bottom
# y = 1 top
# z = 0 back
# z = 1 front
# Result: The displacement at the top node in the z direction should match
# the prescribed displacement. Also, the z acceleration should
# be two triangular pulses, one peaking at 0.1 and another peaking at
# 0.2.
[Mesh]
type = GeneratedMesh
dim = 3 # Dimension of the mesh
nx = 1 # Number of elements in the x direction
ny = 1 # Number of elements in the y direction
nz = 1 # Number of elements in the z direction
xmin = 0.0
xmax = 1
ymin = 0.0
ymax = 1
zmin = 0.0
zmax = 1
allow_renumbering = false # So NodalVariableValue can index by id
[]
[Variables] # variables that are solved
[./disp_x]
[../]
[./disp_y]
[../]
[./disp_z]
[../]
[]
[AuxVariables] # variables that are calculated for output
[./accel_x]
[../]
[./vel_x]
[../]
[./accel_y]
[../]
[./vel_y]
[../]
[./accel_z]
[../]
[./vel_z]
[../]
[./stress_xx]
order = CONSTANT
family = MONOMIAL
[../]
[./strain_xx]
order = CONSTANT
family = MONOMIAL
[../]
[./stress_yy]
order = CONSTANT
family = MONOMIAL
[../]
[./strain_yy]
order = CONSTANT
family = MONOMIAL
[../]
[./stress_zz]
order = CONSTANT
family = MONOMIAL
[../]
[./strain_zz]
order = CONSTANT
family = MONOMIAL
[../]
[]
[Kernels]
[./DynamicTensorMechanics] # zeta*K*vel + K * disp
displacements = 'disp_x disp_y disp_z'
stiffness_damping_coefficient = 0.000025
[../]
[./inertia_x] # M*accel + eta*M*vel
type = InertialForce
variable = disp_x
velocity = vel_x
acceleration = accel_x
beta = 0.25 # Newmark time integration
gamma = 0.5 # Newmark time integration
eta = 19.63
[../]
[./inertia_y]
type = InertialForce
variable = disp_y
velocity = vel_y
acceleration = accel_y
beta = 0.25
gamma = 0.5
eta = 19.63
[../]
[./inertia_z]
type = InertialForce
variable = disp_z
velocity = vel_z
acceleration = accel_z
beta = 0.25
gamma = 0.5
eta = 19.63
[../]
[]
[AuxKernels]
[./accel_x] # Calculates and stores acceleration at the end of time step
type = NewmarkAccelAux
variable = accel_x
displacement = disp_x
velocity = vel_x
beta = 0.25
execute_on = timestep_end
[../]
[./vel_x] # Calculates and stores velocity at the end of the time step
type = NewmarkVelAux
variable = vel_x
acceleration = accel_x
gamma = 0.5
execute_on = timestep_end
[../]
[./accel_y]
type = NewmarkAccelAux
variable = accel_y
displacement = disp_y
velocity = vel_y
beta = 0.25
execute_on = timestep_end
[../]
[./vel_y]
type = NewmarkVelAux
variable = vel_y
acceleration = accel_y
gamma = 0.5
execute_on = timestep_end
[../]
[./accel_z]
type = NewmarkAccelAux
variable = accel_z
displacement = disp_z
velocity = vel_z
beta = 0.25
execute_on = timestep_end
[../]
[./vel_z]
type = NewmarkVelAux
variable = vel_z
acceleration = accel_z
gamma = 0.5
execute_on = timestep_end
[../]
[./stress_xx]
type = RankTwoAux
rank_two_tensor = stress
variable = stress_xx
index_i = 0
index_j = 0
[../]
[./strain_xx]
type = RankTwoAux
rank_two_tensor = total_strain
variable = strain_xx
index_i = 0
index_j = 0
[../]
[./stress_yy]
type = RankTwoAux
rank_two_tensor = stress
variable = stress_yy
index_i = 1
index_j = 1
[../]
[./strain_yy]
type = RankTwoAux
rank_two_tensor = total_strain
variable = strain_yy
index_i = 1
index_j = 1
[../]
[./stress_zz]
type = RankTwoAux
rank_two_tensor = stress
variable = stress_zz
index_i = 2
index_j = 2
[../]
[./strain_zz]
type = RankTwoAux
rank_two_tensor = total_strain
variable = strain_zz
index_i = 2
index_j = 2
[../]
[]
[Functions]
[./displacement_front]
type = PiecewiseLinear
data_file = 'displacement.csv'
format = columns
[../]
[]
[BCs]
[./Preset_displacement]
type = PresetDisplacement
variable = disp_z
function = displacement_front
boundary = front
beta = 0.25
velocity = vel_z
acceleration = accel_z
[../]
[./anchor_x]
type = DirichletBC
variable = disp_x
boundary = left
value = 0.0
[../]
[./anchor_y]
type = DirichletBC
variable = disp_y
boundary = bottom
value = 0.0
[../]
[./anchor_z]
type = DirichletBC
variable = disp_z
boundary = back
value = 0.0
[../]
[]
[Materials]
[./elasticity_tensor]
youngs_modulus = 325e6 #Pa
poissons_ratio = 0.3
type = ComputeIsotropicElasticityTensor
block = 0
[../]
[./strain]
#Computes the strain, assuming small strains
type = ComputeSmallStrain
block = 0
displacements = 'disp_x disp_y disp_z'
[../]
[./stress]
#Computes the stress, using linear elasticity
type = ComputeLinearElasticStress
block = 0
[../]
[./density]
type = GenericConstantMaterial
block = 0
prop_names = density
prop_values = 2000 #kg/m3
[../]
[]
[Executioner]
type = Transient
start_time = 0
end_time = 3.0
l_tol = 1e-6
nl_rel_tol = 1e-6
nl_abs_tol = 1e-6
dt = 0.1
timestep_tolerance = 1e-6
[]
[Postprocessors] # These quantites are printed to a csv file at every time step
[./_dt]
type = TimestepSize
[../]
[./accel_6x]
type = NodalVariableValue
nodeid = 6
variable = accel_x
[../]
[./accel_6y]
type = NodalVariableValue
nodeid = 6
variable = accel_y
[../]
[./accel_6z]
type = NodalVariableValue
nodeid = 6
variable = accel_z
[../]
[./vel_6x]
type = NodalVariableValue
nodeid = 6
variable = vel_x
[../]
[./vel_6y]
type = NodalVariableValue
nodeid = 6
variable = vel_y
[../]
[./vel_6z]
type = NodalVariableValue
nodeid = 6
variable = vel_z
[../]
[./disp_6x]
type = NodalVariableValue
nodeid = 6
variable = disp_x
[../]
[./disp_6y]
type = NodalVariableValue
nodeid = 6
variable = disp_y
[../]
[./disp_6z]
type = NodalVariableValue
nodeid = 6
variable = disp_z
[../]
[]
[Outputs]
exodus = true
csv = true
perf_graph = true
[]
(modules/tensor_mechanics/test/tests/central_difference/consistent/2D/2d_consistent_implicit.i)
# Test for the central difference time integrator for a 2D mesh
[Mesh]
type = GeneratedMesh
dim = 2
nx = 1
ny = 2
xmin = 0.0
xmax = 1.0
ymin = 0.0
ymax = 2.0
[]
[Variables]
[./disp_x]
[../]
[./disp_y]
[../]
[]
[AuxVariables]
[./vel_x]
[../]
[./accel_x]
[../]
[./vel_y]
[../]
[./accel_y]
[../]
[]
[Kernels]
[./DynamicTensorMechanics]
displacements = 'disp_x disp_y'
[../]
[./inertia_x]
type = InertialForce
variable = disp_x
[../]
[./inertia_y]
type = InertialForce
variable = disp_y
[../]
[]
[AuxKernels]
[./accel_x]
type = TestNewmarkTI
variable = accel_x
displacement = disp_x
first = false
[../]
[./vel_x]
type = TestNewmarkTI
variable = vel_x
displacement = disp_x
[../]
[./accel_y]
type = TestNewmarkTI
variable = accel_y
displacement = disp_y
first = false
[../]
[./vel_y]
type = TestNewmarkTI
variable = vel_y
displacement = disp_y
[../]
[]
[BCs]
[./y_bot]
type = DirichletBC
variable = disp_y
boundary = bottom
value = 0.0
[../]
[./x_bot]
type = PresetDisplacement
boundary = bottom
variable = disp_x
beta = 0.25
velocity = vel_x
acceleration = accel_x
function = disp
[../]
[]
[Functions]
[./disp]
type = PiecewiseLinear
x = '0.0 1.0 2.0 3.0 4.0' # time
y = '0.0 1.0 0.0 -1.0 0.0' # displacement
[../]
[]
[Materials]
[./elasticity_tensor_block]
type = ComputeIsotropicElasticityTensor
youngs_modulus = 1e6
poissons_ratio = 0.25
block = 0
[../]
[./strain_block]
type = ComputeIncrementalSmallStrain
block = 0
displacements = 'disp_x disp_y'
[../]
[./stress_block]
type = ComputeFiniteStrainElasticStress
block = 0
[../]
[./density]
type = GenericConstantMaterial
block = 0
prop_names = density
prop_values = 1e4
[../]
[]
[Preconditioning]
[./andy]
type = SMP
full = true
[../]
[]
[Executioner]
type = Transient
solve_type = NEWTON
nl_abs_tol = 1e-11
nl_rel_tol = 1e-11
start_time = -0.01
end_time = 0.1
dt = 0.005
timestep_tolerance = 1e-6
[./TimeIntegrator]
type = NewmarkBeta
beta = 0.25
gamma = 0.5
[../]
[]
[Postprocessors]
[./_dt]
type = TimestepSize
[../]
[./accel_2x]
type = PointValue
point = '1.0 2.0 0.0'
variable = accel_x
[../]
[./accel_2y]
type = PointValue
point = '1.0 2.0 0.0'
variable = accel_y
[../]
[]
[Outputs]
exodus = false
csv = true
[]