DELTIM
DELTIM, DTIME, DTMIN, DTMAX, Carry
Specifies the time step sizes to be used for the current
load step.
DTIMETime step size for this step. If automatic time stepping is used (AUTOTS),
DTIMEis the starting time substep.If contact elements (TARGE169, TARGE170, CONTA172, CONTA174, CONTA175, or CONTA177) are used, defaults to
TIMEorTIME/20 (whereTIMEis the time at the end of the load step as set on the TIME command), depending on the physics of the model. If none of these contact elements are used, defaults toTIME.DTMINMinimum time step (if automatic time stepping is used). The program automatically determines the default based on the physics of the model.
DTMAXMaximum time step (if automatic time stepping is used). The program automatically determines the default based on the physics of the model.
CarryTime step carry over key:
OFF
—
Use
DTIMEas 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 NSUBST for an alternative input.
Use consistent values for DTIME and TIME (TIME). For example, using
0.9 for DTIME and 1.0 for TIME results in one time step because 1.0 (TIME) is divisible by .9 (DTIME) at most once. If you intend to load in 10 increments over a time
span of 1.0, use 0.1 for DTIME and 1.0
for TIME.
The program calculates the initial incremental time so that
(EndingTime - StartingTime)/DTIME is an integer, which may affect
the initial incremental time that you specify. For example, if the
starting time is 0, the ending time is 1, and the initial incremental
time is 0.4, the program rounds to the nearest integer and adjusts
the time to 0.33333.
For solution efficiency, specify values for all fields of this command.
Changing the time step size upon restarting an analysis during a load step is not recommended. You should only change the time step size between load steps.
This command is also valid in PREP7.