3D Connexion Version 6.6

*VISCO

21.3 *VISCO: Transient, static, stress/displacement analysis with time-dependent

material response (creep, swelling, and viscoelasticity).

This option is used to obtain a transientstatic response in an analysis with time-dependent material behavior

(creep, swelling, and viscoelasticity).

Product: ABAQUS/Standard

Type: History data

Level: Step

References:

•“Quasi-static analysis,” Section 6.2.5of the ABAQUS Analysis User ’sManual

•“Rate-dependentplasticity: creep and swelling,” Section 18.2.4 of the ABAQUS Analysis User’s Manual

Optional parameters:

CETOL

Setthis parameter equal to the maximum difference in the creep strain increment calculated from the

creepstrain rates based on conditions at the beginning and on conditions at the end of the increment,

thus controlling the accuracy of the creepintegration. In general, the tolerance can be calculated

by choosing an acceptable stress error tolerance and dividingby 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 omitte d, ﬁxed time

increments are used.

CREEP

Set CREEP=EXPLICIT to use explicit integration for creep behavior throughout the st ep, 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 18.2.4 of the ABAQUS Analysis User’s

Manual, for details on the integration scheme.

FACT OR

Set this parameter equal to the damping factor to be used in the automatic damping algorithm

(see “Solving nonlinear problems,” Section 7.1.1 of the ABAQUS Analysis U ser’s Manual) if

the problem is expected to be unstable due to local instabilitiesand 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.

21.3–1

ABAQUS Version 6.1 Module: ID:

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