Card 9 - STEP Solution Steps Control Card

This optional card specifies the parameters and options for setting up a solution sequence with different stages of the same simulation.

Parameters: KODE, N1, T1, T2, T3

KODE

KODE is the code dSTEP (or 94)

N1

N1 is the STEP card ID. Cards with the same ID reference the same Solution Step.

T1 = AUTODELTAT

T1 = AUTODELTAT (or 11) specifies the temperature error tolerance (i.e., maximum temperature error estimate) when automatic time stepping is used. This value is specified in T2.

T1 = DTEMPMAX

T1 = DTEMPMAX (or 4) is OBSOLETE. It specifies the maximum allowable temperature change of the PARAM DTEMPMAX method when automatic time stepping is used. This value is specified in T2.

T1 = DTMAX

T1 = DTMAX (or 6) specifies the upper limit on the integration time steps obtained during automatic time stepping. This value is specified in T2.

T1 = DTMIN

T1 = DTMIN (or 5) specifies the lower limit on the integration time steps obtained during automatic time stepping. This value is specified in T2.

T1 = ENDTIME

T1 = ENDTIME (or 2) specifies the value of end time of the solution step in T2. For steady state steps, this is the time point where the steady state simulation is to be performed for the given step. If the step is of type transient, it covers the transient integration time interval from the end time of the previous STEP card to the current step end time. The end time values of the first and last step are taken to be the initial and final time of the simulation and they override the TST and TF fields of Card 2b.

T1 = INCREMENTS

T1 = INCREMENTS (or 10) specifies the number of increments if the TIMESTEP option is set to AUTOMATIC. The integration time step upper limit is defined as the number of increments throughout the time duration of the solution step. Therefore, the maximum integration time step is the solution step duration time divided by the number of increments. This number of increments is specified in T2.

T1 = NAME

T1 = NAME (or 9) specifies the solution step user-defined name in T2.

T1 = OUTPUT

  • T1 = OUTPUT (or 7) specifies the result printout options.
  • T2 = ALL (or 4) performs printout at all integration and coupling time steps between the thermal and structural solvers.
  • T2 = COUPLED (or 3) performs result printout only at coupling times between the thermal and structural solvers.
  • T2 = END (or 2), then result printout is done only at the end time of the solution step.
  • T2 = YES (or 1), then result printout will be performed at each integration time step.

T1 = PRINT

T1 = PRINT (or 8) specifies the thermal output request ID that should be used for the given STEP card in T2, unless it is set to GLOBAL (or -1).

T1 = TIMESTEP

T1 = TIMESTEP (or 3) specifies how the transient integration time step is to be determined for the given solution step.

  • T2 = DT the integration time step is a constant value given in T3.
  • T2 = AUTOMATIC (or 5) the integration time step is determined automatically using the PARAM AUTODELTAT method.
  • T2 = NUMBER (or 3) the integration time step is a constant value equal to the total duration of the current time step interval (from previous solution step end time to the current solution step end time) divided by the integer value provided in T3 (if that value is 0 or absent, then it will be taken as 1).

T1 = TYPE

T1 = TYPE (or 1) defines the solution type for the given step.

  • T2 = STEADY (or 1) treats the given step as steady state.
  • T2 = TRANSIENT (or 2) or blank, treats the given step as transient.

Code example

$
$ Solution Steps
$
STEP 1 TYPE TRANSIENT
STEP 1 ENDTIME  0.000000E+00
STEP 1 TIMESTEP NUMBER 100
STEP 1 OUTPUT END
STEP 1 PRINT GLOBAL
$
STEP 2 TYPE TRANSIENT
STEP 2 ENDTIME  2.500000E+04
STEP 2 TIMESTEP DT 0.5
STEP 2 OUTPUT YES
STEP 2 PRINT GLOBAL

Notes

The STEP cards allow you to set up a solution sequence so that different stages of the same simulation use different settings for the solution type (transient or steady state), integration time step, and printing step control. If present, they override the corresponding settings (DTP, DT, TST, TF) of the Analyzer Control Card 2b. The simulation stages corresponding to different STEP cards are executed in the order that those cards are written in the INPF file.