3D Connexion Version 6.6

*SOILS

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 and CONSOLIDATIONparameters and overrides the automatic calculation of the

damping factor based on a value of the dissipated energy fraction.

STABILIZE

Include this parameter to use automatic stabilization if the proble m is expected to be unstable due

to local instabilities. Set this parameter equal to the dissipated energy fraction ofthe automatic

damping algorithm (see “Solving nonlinear problems,” S ection 7.1.1 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 defaultvalue of the dissipated energy fraction

is 2 × 10−4. If the FACTORparamet er is used, any value of the dissipated energy fraction will be

overridden by the damping factor.

This parameter can be used only in conjunction with the CONSOLIDATIONparameter.

UTOL

This parameter will invoke automatic time incrementa tion. If both the UTOL and the CETOL

parameters are omitted, ﬁxed time increments will be use d.

Set this parameter equal to the maximum pore pressure change permitted in any increment (in

pressure units) in a transient consolidation analysis. ABAQUS/Standard will restrict the time step

to ensure that thisvalue will not be exceeded at any node (except nodes with boundary conditions)

during any increment of the analysis.

Set this value equalto any nonzero value in a steady-state analysis (to activate automatic time

incrementation).

Data line to deﬁne incrementation for a soils analysis:

First (and only) line:

1. Initialt ime increment. This value will be modiﬁed a s required if the automatic time stepping

scheme is used; it will be used as a constant time increment otherw ise.

2. Timeperiod. If END=SS is chosen, the step ends after thistim e periodor when steady-state

conditions are reached, whichever comes ﬁrst.

3. Minimum time increment allowed. If ABAQUS/Standard ﬁnds it needs a smaller time

increment than thisvalue, the analysis is terminated. Ifthis entry is zero, a default value of the

smaller of the suggested initial time increment or10−5 times the total tim e period is assumed.

Only used for automatic time incrementation.

4. Ma ximum time increment allowed. If this value is not speciﬁed, the upper limit is the total

time period. Only used for autom atic time incrementation.

18.21–2

ABAQUS Version 6.1 Module: ID:

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