This option is used to obtain a transient static response in an analysis with time-dependent material behavior (creep, swelling, and viscoelasticity).
Product: ABAQUS/Standard
Type: History data
Level: Step
Set this parameter equal to the maximum difference in the creep strain increment calculated from the creep strain rates based on conditions at the beginning and on conditions at the end of the increment, thus controlling the accuracy of the creep integration. In general, the tolerance can be calculated by choosing an acceptable stress error tolerance and dividing by a typical elastic modulus. If the model consists of a linear viscoelastic material characterized by the *VISCOELASTIC option, a looser tolerance of the order of the elastic strains can be used. If CETOL is omitted, fixed time increments are used.
Set CREEP=EXPLICIT to use explicit integration for creep behavior throughout the step, which may sometimes be computationally less expensive. The time increment will be limited by the accuracy tolerance (CETOL) and by the stability limit of the forward difference operator. See “Rate-dependent plasticity: creep and swelling,” Section 11.2.4 of the ABAQUS Analysis User's Manual, for details on the integration scheme.
Set this parameter equal to the damping factor to be used in the automatic damping algorithm (see “Solving nonlinear problems,” Section 8.2.1 of the ABAQUS Analysis User's Manual) if the problem is expected to be unstable due to local instabilities and the damping factor calculated by ABAQUS/Standard is not suitable. This parameter must be used in conjunction with the STABILIZE parameter and overrides the automatic calculation of the damping factor based on a value of the dissipated energy fraction.
Include this parameter to use automatic stabilization if the problem is expected to be unstable due to local instabilities. Set this parameter equal to the dissipated energy fraction of the automatic damping algorithm (see “Solving nonlinear problems,” Section 8.2.1 of the ABAQUS Analysis User's Manual). If this parameter is omitted, the stabilization algorithm is not activated. If this parameter is included without a specified value, the default value of the dissipated energy fraction is 2 × 10–4. If the FACTOR parameter is used, any value of the dissipated energy fraction will be overridden by the damping factor.
First (and only) line:
Suggested initial time increment. This value should be reasonably correct (in agreement with the strain change allowed with the CETOL parameter) but may be reduced if automatic time incrementation is being used.
Time period of the step.
Minimum time increment allowed. If ABAQUS/Standard finds it needs a smaller time increment than this value, the analysis is terminated. If this entry is zero, a default value of the smaller of the suggested initial time increment or 10–5 times the total time period is assumed.
Maximum time increment allowed. Only used for automatic time incrementation. If this value is not specified, no upper limit is imposed.