NSUBST
NSUBST, NSBSTP, NSBMX, NSBMN, Carry
Specifies the number of substeps to be taken this load
step.
NSBSTPNumber of substeps to be used for this load step (that is, the time step size or frequency increment). If automatic time stepping is used (AUTOTS),
NSBSTPdefines the size of the first substep.If contact elements (TARGE169, TARGE170, CONTA172, CONTA174, CONTA175, or CONTA177) are used, defaults to 1 or 20 substeps, depending on the physics of the model. If none of these contact elements are used, defaults to 1 substep.
NSBMXMaximum number of substeps to be taken (that is, the minimum time step size) if automatic time stepping is used. The program automatically determines the default based on the physics of the model.
NSBMNMinimum number of substeps to be taken (that is, the maximum time step size) if automatic time stepping is used. The program automatically determines the default based on the physics of the model.
CarryTime step carryover key (program-determined default depending on the problem physics):
OFF
—
Use
NSBSTPto define time step at start of each load step.ON
—
Use final time step from previous load step as the starting time step (if automatic time stepping is used).
The program automatically determines the default based on the physics of the model.
Notes
See DELTIM for an alternative input. It is recommended that all fields of this command be specified for solution efficiency and robustness.
When the arc-length method is active (ARCLEN command), the NSBMX and NSBMN arguments are ignored.
Changing the number of substeps upon restarting an analysis during a load step is not recommended. You should only change the number of substeps between load steps.
For a harmonic balance method (HBM)
analysis, use NSBSTP to specify the number of substeps when
no continuation method is used (CorrMeth = OFF on
HBMOPT,CONTSET). The first substep is at FREQB +
(FREQE -
FREQB)/NSBSTP as in other harmonic
analyses, where FREQB and FREQE are the
beginning and ending frequencies of a solution specified with the HARFRQ
command. NSBSTP is the only argument used for HBM analyses.
This command is also valid in PREP7.