Time History Case

Damping Control

Constructor

TH.Damping.Modal(dampRatioAllMode=0.05, ModeDampingOverrides=None)

Constructs Damping control with Modal damping

Parameters

dampRatioAllMode: Damping ratio applied to all modes. Default is 0.05 (5% damping).
ModeDampingOverrides: Optional list of (ModeNumber, DampingRatio) tuples to override the damping ratio for specific modes, e.g. [(1, 0.006), (2, 0.007)].

Example

damp = TH.Damping.Modal(
    dampRatioAllMode=0.05,
    ModeDampingOverrides=[(1, 0.006), (2, 0.007)]
)
TH.Case.LinearModal(Name="TH_1", damping_control=damp)

Mass and Stiffness Proportional Damping

Constructor

TH.Damping.MassStiffness(inpType=1, massProp=None, stiffProp=None, freq1=None, damp1=0, freq2=None, damp2=0, period1=None, period2=None)

Constructs Damping control with Mass & Stiffness (Rayleigh) Proportional damping

Parameters

inpType: Damping input method/type.
1 : Constant (Direct Specification) | 2 : Frequency-Proportional (Calc. from Frequency/Period)
massProp: Mass proportional damping coefficient. Used when inpType=1.
stiffProp: Stiffness proportional damping coefficient. Used when inpType=1.
freq1: First reference frequency for damping calculation. Used when inpType=2.
damp1: Damping ratio corresponding to freq1 (or period1).
freq2: Second reference frequency for damping calculation. Used when inpType=2.
damp2: Damping ratio corresponding to freq2 (or period2).
period1: First reference period for damping calculation. Alternative to freq1 — used when inpType=2.
period2: Second reference period for damping calculation. Alternative to freq2 — used when inpType=2.

Provide either freq1/freq2 or period1/period2, not both.

Example

# Constant Mass & Stiffness Proportional damping
damp1 = TH.Damping.MassStiffness(inpType=1, massProp=0, stiffProp=0)

# Frequency-Proportional damping, by frequency
damp2 = TH.Damping.MassStiffness(
    inpType=2, freq1=1, damp1=0.05, freq2=5, damp2=0.05
)

TH.Case.LinearDirectInt(Name="TH_2", damping_control=damp1, time_integration_params="CONSTANT")

Strain Energy Proportional Damping

Constructor

TH.Damping.StrainEnergy()

Constructs Damping control with Strain Energy Proportional damping

Example

damp = TH.Damping.StrainEnergy()
TH.Case.LinearModal(Name="TH_3", damping_control=damp)

Element Mass and Stiffness Proportional Damping

Constructor

TH.Damping.ElementMassStiffness()

Constructs Damping control with Element-Level Mass & Stiffness Proportional damping

Example

damp = TH.Damping.ElementMassStiffness()
TH.Case.LinearModal(Name="TH_4", damping_control=damp)

Load Control

Initial Load (Global Control)

Constructor

TH.InitialLoad_Control(Use_Initial_Load=True, Cumulate_DVA_Results=False, Keep_Final_Step_Loads_Constant=False, Geometricnonlinearity_type=False)

Constructs a starting condition control that begins the case from the Initial Load (Global Control) condition

Parameters

Use_Initial_Load: Whether to use the Initial Load (Global Control) option.
Cumulate_DVA_Results: Cumulate the Displacement/Velocity/Acceleration results. Applied only when Use_Initial_Load=True.
Keep_Final_Step_Loads_Constant: Keep the loads of the final step constant for the remainder of the analysis. Applied only when Use_Initial_Load=True.
Geometricnonlinearity_type: Geometric nonlinearity control.
False : Standard | True : Large Displacement

Example

ilc = TH.InitialLoad_Control(
    Use_Initial_Load=True,
    Cumulate_DVA_Results=True,
    Keep_Final_Step_Loads_Constant=False
)
TH.Case.NonLinearDirectInt(
    Name="TH_Seismic_2",
    endTime=30,
    timeIncrement=0.001,
    subsequent_control=ilc,
    damping_control=TH.Damping.MassStiffness(inpType=1, massProp=0, stiffProp=0),
    time_integration_params="CONSTANT"
)

Subsequent Control

Constructor

TH.Subsequent_Control(load_case=None, Initial_element_forces_table=False, Initial_forces_geometric_stiffness=False, Geometricnonlinearity_type=False)

Constructs Subsequent Control data.

Parameters

load_case: List [LoadCaseType, LoadCaseName] identifying the preceding load case to continue from, e.g. ["ST", "SIDL"]. If LoadCaseType is "TH", two optional input can be add in list: [LoadCaseType, LoadCaseName, Cumulate_DVA_Results, Keep_Final_Step_Loads_Constant].
Initial_element_forces_table: Continue from the Initial Element Forces (Table). Only valid when Geometricnonlinearity_type=False.
Initial_forces_geometric_stiffness: Continue using Initial Forces for Geometric Stiffness. Only valid when Geometricnonlinearity_type=True.
Geometricnonlinearity_type: Geometric nonlinearity control.
False : Standard | True : Large Displacement

Example

# 1.With the Static Load Case
sc1 = TH.Subsequent_Control(load_case=["ST", "Case Name"])
TH.Case.LinearModal(Name="TH_A", THtype="Periodic", subsequent_control=sc1)

# 2. With the Initial Element Forces (Table)
sc2 = TH.Subsequent_Control(Initial_element_forces_table=True)
TH.Case.LinearModal(Name="TH_B", THtype="Periodic", subsequent_control=sc2)

Nonlinear Iteration Control

Constructor

TH.NonlinearIteration_Control(Maximum_Iteration=10, Minimum_Step_Size=1e-05, Max_num_of_sub_steps=10, Displacement_norm=None, Force_norm=None, Energy_norm=None, Startline_search_Iteration=None, Runge_kutta_method="FEHLBERG", Tolerance=1e-08, Check_Convergence=True)

Constructs the nonlinear iteration/convergence settings used by nonlinear Time History cases

Parameters

Maximum_Iteration: Maximum number of iterations per step.
Minimum_Step_Size: Minimum allowable sub-step size. Not applied for NonLinearStatic cases.
Max_num_of_sub_steps: Maximum number of sub-steps.
Displacement_norm: Convergence tolerance for the displacement norm. If None, the displacement norm check is disabled.
Force_norm: Convergence tolerance for the force norm. If None, the force norm check is disabled.
Energy_norm: Convergence tolerance for the energy norm. If None, the energy norm check is disabled.
Startline_search_Iteration: Iteration number at which line search begins. If None, line search is disabled.
Runge_kutta_method: Runge-Kutta integration method.
'FEHLBERG' | 'CASHKARP'
Tolerance: Convergence tolerance.
Check_Convergence: Enables convergence checking.

Example

nl_iter = TH.NonlinearIteration_Control(
    Maximum_Iteration=10,
    Minimum_Step_Size=1e-05,
    Displacement_norm=0.001,
    Force_norm=0.001,
    Runge_kutta_method="FEHLBERG",
    Tolerance=1e-08,
    Check_Convergence=False
)
TH.Case.NonLinearModal(
    Name="TH_NL_1",
    endTime=22,
    timeIncrement=0.0001,
    damping_control=TH.Damping.Modal(dampRatioAllMode=0.0106079),
    NonlinearIteration_Control=nl_iter
)

Case

Constructor

TH.Case.LinearModal(Name, THtype='Transient', endTime=1, timeIncrement=0.01, stepIncOutput=1, subsequent_control=None, damping_control=None, id=None)

Constructs a Linear Time History Load Case

Parameters

Name: Name of the time history load case.
THtype: Time history analysis type.
'Transient' | 'Periodic'
endTime: Analysis end time.
timeIncrement: Time step increment.
stepIncOutput: Output every N-th step.
subsequent_control: Starting condition control object — TH.InitialLoad_Control or TH.Subsequent_Control.
damping_control: Damping control object — TH.Damping.Modal, .MassStiffness, .StrainEnergy, or .ElementMassStiffness.
id: Manually assign an ID. If None, ID will be auto-assigned.

Example

TH.Case.LinearModal(
    Name="TH_Modal_1",
    THtype="Transient",
    endTime=42,
    timeIncrement=0.0001,
    stepIncOutput=1,
    subsequent_control=None,
    damping_control=TH.Damping.Modal(dampRatioAllMode=0.0106079)
)
TH.Case.create()

Constructor

TH.Case.NonLinearModal(Name, endTime=1, timeIncrement=0.01, stepIncOutput=1, subsequent_control=None, damping_control=None, NonlinearIteration_Control=None, id=None)

Constructs a Nonlinear Time History Load Case (Transient only)

Parameters

Name: Name of the time history load case.
endTime: Analysis end time.
timeIncrement: Time step increment.
stepIncOutput: Output every N-th step.
subsequent_control: Starting condition control object — TH.InitialLoad_Control or TH.Subsequent_Control.
damping_control: Damping control object.
NonlinearIteration_Control: Nonlinear iteration control object — TH.NonlinearIteration_Control.
id: Manually assign an ID. If None, ID will be auto-assigned.

Example

TH.Case.NonLinearModal(
    Name="TH_NLModal_1",
    endTime=32,
    timeIncrement=0.0001,
    stepIncOutput=1,
    subsequent_control=None,
    damping_control=TH.Damping.Modal(dampRatioAllMode=0.0106079),
    NonlinearIteration_Control=TH.NonlinearIteration_Control(
        Maximum_Iteration=10,
        Displacement_norm=0.001,
        Check_Convergence=False
    )
)
TH.Case.create()

Linear Direct Integration

Constructor

TH.Case.LinearDirectInt(Name, endTime=1, timeIncrement=0.01, stepIncOutput=1, subsequent_control=None, damping_control=None, time_integration_params="LINEAR", id=None)

Constructs a Linear, Direct-Integration Time History Load Case

Parameters

Name: Name of the time history load case.
endTime: Analysis end time.
timeIncrement: Time step increment.
stepIncOutput: Output every N-th step.
subsequent_control: Starting condition control object — TH.InitialLoad_Control or TH.Subsequent_Control.
damping_control: Damping control object.
time_integration_params: Newmark integration parameters.
'CONSTANT' : Average (Constant) Acceleration | 'LINEAR' : Linear Acceleration | (GAMMA, BETA) : User Input
id: Manually assign an ID. If None, ID will be auto-assigned.

Example

TH.Case.LinearDirectInt(
    Name="TH_Direct_1",
    endTime=34,
    timeIncrement=0.0001,
    stepIncOutput=1,
    subsequent_control=None,
    damping_control=TH.Damping.MassStiffness(inpType=1, massProp=0, stiffProp=0),
    time_integration_params="CONSTANT"
)
TH.Case.create()

Nonlinear Direct Integration

Constructor

TH.Case.NonLinearDirectInt(Name, endTime=1, timeIncrement=0.01, stepIncOutput=1, subsequent_control=None, damping_control=None, time_integration_params="LINEAR", NonlinearIteration_Control=None, damping_matrix_update="NO", id=None)

Constructs a Nonlinear, Direct-Integration Time History Load Case

Parameters

Name: Name of the time history load case.
endTime: Analysis end time.
timeIncrement: Time step increment.
stepIncOutput: Output every N-th step.
subsequent_control: Starting condition control object — TH.InitialLoad_Control or TH.Subsequent_Control.
damping_control: Damping control object.
time_integration_params: Newmark integration parameters.
'CONSTANT' | 'LINEAR' | (GAMMA, BETA)
NonlinearIteration_Control: Nonlinear iteration control object.
damping_matrix_update: Update the damping matrix at each step.
'YES' | 'NO'
id: Manually assign an ID. If None, ID will be auto-assigned.

Example

TH.Case.NonLinearDirectInt(
    Name="TH_NLDirect_1",
    endTime=30,
    timeIncrement=0.0001,
    stepIncOutput=1,
    subsequent_control=TH.InitialLoad_Control(Use_Initial_Load=True),
    damping_control=TH.Damping.MassStiffness(inpType=1, massProp=0, stiffProp=0),
    time_integration_params="CONSTANT",
    NonlinearIteration_Control=TH.NonlinearIteration_Control(Maximum_Iteration=10),
    damping_matrix_update="NO"
)
TH.Case.create()

Nonlinear Static

Constructor

TH.Case.NonLinearStatic(Name, endTime=1, incrementSteps=1, subsequent_control=None, load_control_scale_factor=1, global_control_maximum_translation_displacement=0, master_node_control=None, load_output_option=False, NonlinearIteration_Control=True, id=None)

Constructs a Nonlinear Static Time History Load Case

Parameters

Name: Name of the time history load case.
endTime: Analysis end time.
incrementSteps: Number of increment steps.
subsequent_control: Starting condition control object — TH.InitialLoad_Control or TH.Subsequent_Control.
load_control_scale_factor: Scale factor used when Load Control governs the increment.
global_control_maximum_translation_displacement: Maximum translational displacement for Global (Displacement) Control. Non-zero enables Global Control.
master_node_control: Tuple (MasterNode, Direction, TargetIncrement) enabling Master-Node Displacement Control.
load_output_option: Output cumulative load results.
NonlinearIteration_Control: Nonlinear iteration control object. If a plain truthy value is passed instead of a control object, a built-in default iteration setting is used.
id: Manually assign an ID. If None, ID will be auto-assigned.

Example

TH.Case.NonLinearStatic(
    Name="TH_NLStatic_1",
    endTime=1,
    incrementSteps=1,
    subsequent_control=TH.InitialLoad_Control(Use_Initial_Load=True),
    load_control_scale_factor=1,
    load_output_option=False,
    NonlinearIteration_Control=TH.NonlinearIteration_Control(Maximum_Iteration=10)
)
TH.Case.create()

Methods

(Shared across all five case types above — LinearModal, NonLinearModal, LinearDirectInt, NonLinearDirectInt, NonLinearStatic)

json

Returns JSON representation of all Time History Load Cases.

print(TH.Case.json())

create

Sends all Time History Load Cases to Civil NX.

TH.Case.create()

get

Fetches Time History Load Case data from Civil NX.

print(TH.Case.get())

sync

Synchronizes Time History Load Cases from Civil NX, rebuilding the correct case type along with its Damping, InitialLoad_Control/Subsequent_Control, and NonlinearIteration_Control sub-objects.

TH.Case.sync()

delete

Deletes all Time History Load Cases from both Python and Civil NX.

TH.Case.delete()

Examples

# 1. Linear Modal, Transient, Modal damping
TH.Case.LinearModal(
    Name="TH_Modal_1",
    THtype="Transient",
    endTime=42,
    timeIncrement=0.0001,
    damping_control=TH.Damping.Modal(0.0106079)
)

# 2. Linear Direct Integration, Mass & Stiffness (constant) damping
TH.Case.LinearDirectInt(
    Name="TH_Direct_1",
    endTime=34,
    timeIncrement=0.0001,
    damping_control=TH.Damping.MassStiffness(inpType=1, massProp=0, stiffProp=0),
    time_integration_params="CONSTANT"
)

# 3. Nonlinear Modal, Modal damping, with nonlinear iteration control
TH.Case.NonLinearModal(
    Name="TH_NLModal_1",
    endTime=32,
    timeIncrement=0.0001,
    damping_control=TH.Damping.Modal(0.0106079),
    NonlinearIteration_Control=TH.NonlinearIteration_Control(
        Maximum_Iteration=10,
        Displacement_norm=0.001,
        Check_Convergence=False
    )
)

# 4. Nonlinear Direct Integration, subsequent to Initial Load
TH.Case.NonLinearDirectInt(
    Name="TH_NLDirect_1",
    endTime=30,
    timeIncrement=0.0001,
    subsequent_control=TH.InitialLoad_Control(Use_Initial_Load=True),
    damping_control=TH.Damping.MassStiffness(inpType=1, massProp=0, stiffProp=0),
    time_integration_params="CONSTANT",
    NonlinearIteration_Control=TH.NonlinearIteration_Control(Maximum_Iteration=10),
    damping_matrix_update="NO"
)

# 5. Nonlinear Static, Load Control, subsequent to Initial Load
TH.Case.NonLinearStatic(
    Name="TH_NLStatic_1",
    subsequent_control=TH.InitialLoad_Control(Use_Initial_Load=True),
    load_control_scale_factor=1,
    NonlinearIteration_Control=TH.NonlinearIteration_Control(Maximum_Iteration=10)
)

TH.Case.create()

Time History Case

Damping Control

Modal Damping

Constructor

Parameters

Example

Mass and Stiffness Proportional Damping

Constructor

Parameters

Example

Strain Energy Proportional Damping

Constructor

Example

Element Mass and Stiffness Proportional Damping

Constructor

Example

Load Control

Initial Load (Global Control)

Constructor

Parameters

Example

Subsequent Control

Constructor

Parameters

Example

Nonlinear Iteration Control

Constructor

Parameters

Example

Case

Linear Modal

Constructor

Parameters

Example

Nonlinear Modal

Constructor

Parameters

Example

Linear Direct Integration

Constructor

Parameters

Example

Nonlinear Direct Integration

Constructor

Parameters

Example

Nonlinear Static

Constructor

Parameters

Example

Methods

json

create

get

sync

delete

Examples