49.32 ViscoStep object

The ViscoStep object is used to obtain a transient static response in an analysis with time-dependent material behavior (creep, swelling, and viscoelasticity).

The ViscoStep object is derived from the AnalysisStep object.

Access
import step
mdb.models[name].steps[name]


49.32.1 ViscoStep(...)

This method creates a ViscoStep object.

Path
mdb.models[name].ViscoStep

Required arguments

name

A String specifying the repository key.

previous

A String specifying the name of the previous step. The new step appears after this step in the list of analysis steps.

Optional arguments

description

A String specifying a description of the new step. The default value is an empty string.

timePeriod

A Float specifying the total time period. The default value is 1.0.

nlgeom

A Boolean specifying whether to allow for geometric nonlinearity. The default value is OFF.

stabilizationMethod

A SymbolicConstant specifying the stabilization type. Possible values are NONE, DISSIPATED_ENERGY_FRACTION, and DAMPING_FACTOR. The default value is NONE.

stabilizationMagnitude

A Float specifying the damping intensity of the automatic damping algorithm if the problem is expected to be unstable, and stabilizationMethod is not NONE. The default value is 2×10–4.

timeIncrementationMethod

A SymbolicConstant specifying the time incrementation method to be used. Possible values are FIXED and AUTOMATIC. The default value is AUTOMATIC.

matrixSolver

A SymbolicConstant specifying the type of solver. Possible values are DIRECT and ITERATIVE. The default value is DIRECT.

matrixStorage

A SymbolicConstant specifying the type of matrix storage. Possible values are SYMMETRIC, UNSYMMETRIC, and SOLVER_DEFAULT. The default value is SOLVER_DEFAULT.

initialInc

A Float specifying the initial time increment. The default value is the total time period for the step.

maxNumInc

An Int specifying the maximum number of increments in a step. The default value is 100.

minInc

A Float specifying the minimum time increment allowed. The default value is the smaller of the suggested initial time increment or 10–5 times the total time period.

maxInc

A Float specifying the maximum time increment allowed. The default is the total time period for the step. The default value is 1.0.

integration

A SymbolicConstant specifying which type of integration to use throughout the step. Possible values are IMPLICIT_EXPLICIT and EXPLICIT_ONLY. The default value is IMPLICIT_EXPLICIT.

cetol

A Float specifying the maximum difference in the creep strain increment calculated from the creep strain rates at the beginning and end of the increment. The default value is 0.0.

amplitude

A SymbolicConstant specifying the amplitude variation for loading magnitudes during the step. Possible values are STEP and RAMP. The default value is STEP.

extrapolation

A SymbolicConstant specifying the type of extrapolation to use in determining the incremental solution for a nonlinear analysis. Possible values are NONE, LINEAR, and PARABOLIC. The default value is LINEAR.

maintainAttributes

A Boolean specifying whether to retain attributes from an existing step with the same name. The default value is False.

solutionTechnique

A SymbolicConstant specifying the technique used to for solving nonlinear equations. Possible values are FULL_NEWTON and QUASI_NEWTON. The default value is FULL_NEWTON.

reformKernel

An Int specifying the number of quasi-Newton iterations allowed before the kernel matrix is reformed.. The default value is 8.

convertSDI

A SymbolicConstant specifying whether to force a new iteration if severe discontinuities occur during an iteration. Possible values are PROPAGATED, CONVERT_SDI_OFF, and CONVERT_SDI_ON. The default value is PROPAGATED.

adaptiveDampingRatio

A Float specifying the maximum allowable ratio of the stabilization energy to the total strain energy and can be used only if stabilizationMethod is not NONE. The default value is 0.05.

continueDampingFactors

A Boolean specifying whether this step will carry over the damping factors from the results of the preceding general step. This parameter must be used in conjunction with the adaptiveDampingRatio parameter. The default value is OFF.

Return value

A ViscoStep object.

Exceptions

RangeError.


49.32.2 setValues(...)

This method modifies the ViscoStep object.

Required arguments

None.

Optional arguments

The optional arguments to setValues are the same as the arguments to the ViscoStep method, except for the name, previous, and maintainAttributes arguments.

Return value

None

Exceptions

RangeError.


49.32.3  Members

The ViscoStep object can have the following members:

name

A String specifying the repository key.

timePeriod

A Float specifying the total time period. The default value is 1.0.

nlgeom

A Boolean specifying whether to allow for geometric nonlinearity. The default value is OFF.

stabilizationMethod

A SymbolicConstant specifying the stabilization type. Possible values are NONE, DISSIPATED_ENERGY_FRACTION, and DAMPING_FACTOR. The default value is NONE.

stabilizationMagnitude

A Float specifying the damping intensity of the automatic damping algorithm if the problem is expected to be unstable, and stabilizationMethod is not NONE. The default value is 2×10–4.

timeIncrementationMethod

A SymbolicConstant specifying the time incrementation method to be used. Possible values are FIXED and AUTOMATIC. The default value is AUTOMATIC.

matrixSolver

A SymbolicConstant specifying the type of solver. Possible values are DIRECT and ITERATIVE. The default value is DIRECT.

matrixStorage

A SymbolicConstant specifying the type of matrix storage. Possible values are SYMMETRIC, UNSYMMETRIC, and SOLVER_DEFAULT. The default value is SOLVER_DEFAULT.

initialInc

A Float specifying the initial time increment. The default value is the total time period for the step.

maxNumInc

An Int specifying the maximum number of increments in a step. The default value is 100.

minInc

A Float specifying the minimum time increment allowed. The default value is the smaller of the suggested initial time increment or 10–5 times the total time period.

maxInc

A Float specifying the maximum time increment allowed. The default is the total time period for the step. The default value is 1.0.

integration

A SymbolicConstant specifying which type of integration to use throughout the step. Possible values are IMPLICIT_EXPLICIT and EXPLICIT_ONLY. The default value is IMPLICIT_EXPLICIT.

cetol

A Float specifying the maximum difference in the creep strain increment calculated from the creep strain rates at the beginning and end of the increment. The default value is 0.0.

amplitude

A SymbolicConstant specifying the amplitude variation for loading magnitudes during the step. Possible values are STEP and RAMP. The default value is STEP.

extrapolation

A SymbolicConstant specifying the type of extrapolation to use in determining the incremental solution for a nonlinear analysis. Possible values are NONE, LINEAR, and PARABOLIC. The default value is LINEAR.

solutionTechnique

A SymbolicConstant specifying the technique used to for solving nonlinear equations. Possible values are FULL_NEWTON and QUASI_NEWTON. The default value is FULL_NEWTON.

reformKernel

An Int specifying the number of quasi-Newton iterations allowed before the kernel matrix is reformed.. The default value is 8.

convertSDI

A SymbolicConstant specifying whether to force a new iteration if severe discontinuities occur during an iteration. Possible values are PROPAGATED, CONVERT_SDI_OFF, and CONVERT_SDI_ON. The default value is PROPAGATED.

adaptiveDampingRatio

A Float specifying the maximum allowable ratio of the stabilization energy to the total strain energy and can be used only if stabilizationMethod is not NONE. The default value is 0.05.

continueDampingFactors

A Boolean specifying whether this step will carry over the damping factors from the results of the preceding general step. This parameter must be used in conjunction with the adaptiveDampingRatio parameter. The default value is OFF.

previous

A String specifying the name of the previous step. The new step appears after this step in the list of analysis steps.

description

A String specifying a description of the new step. The default value is an empty string.

explicit

A SymbolicConstant specifying whether the step has an explicit procedure type (procedureType=ANNEAL, DYNAMIC_EXPLICIT, or DYNAMIC_TEMP_DISPLACEMENT).

perturbation

A Boolean specifying whether the step has a perturbation procedure type.

nonmechanical

A Boolean specifying whether the step has a mechanical procedure type.

procedureType

A SymbolicConstant specifying the Abaqus procedure. Possible values are:

  • ANNEAL

  • BUCKLE

  • COMPLEX_FREQUENCY

  • COUPLED_TEMP_DISPLACEMENT

  • COUPLED_THERMAL_ELECTRIC

  • DIRECT_CYCLIC

  • DYNAMIC_IMPLICIT

  • DYNAMIC_EXPLICIT

  • DYNAMIC_SUBSPACE

  • DYNAMIC_TEMP_DISPLACEMENT

  • COUPLED_THERMAL_ELECTRICAL_STRUCTURAL

  • FLOW

  • FREQUENCY

  • GEOSTATIC

  • HEAT_TRANSFER

  • MASS_DIFFUSION

  • MODAL_DYNAMICS

  • RANDOM_RESPONSE

  • RESPONSE_SPECTRUM

  • SOILS

  • STATIC_GENERAL

  • STATIC_LINEAR_PERTURBATION

  • STATIC_RIKS

  • STEADY_STATE_DIRECT

  • STEADY_STATE_MODAL

  • STEADY_STATE_SUBSPACE

  • VISCO

suppressed

A Boolean specifying whether the step is suppressed or not. The default value is OFF.

fieldOutputRequestState

A repository of FieldOutputRequestState objects.

historyOutputRequestState

A repository of HistoryOutputRequestState objects.

diagnosticPrint

A DiagnosticPrint object.

monitor

A Monitor object.

restart

A Restart object.

adaptiveMeshConstraintStates

A repository of AdaptiveMeshConstraintState objects.

adaptiveMeshDomains

A repository of AdaptiveMeshDomain objects.

control

A Control object.

solverControl

A SolverControl object.

boundaryConditionStates

A repository of BoundaryConditionState objects.

interactionStates

A repository of InteractionState objects.

loadStates

A repository of LoadState objects.

loadCases

A repository of LoadCase objects.

predefinedFieldStates

A repository of PredefinedFieldState objects.


49.32.4  Corresponding analysis keywords

*VISCO
*STEP