TSTEP

Subcase Information Entry The TSTEP command can be used to select integration for transient analysis.

Format

TSTEP (type) = option

Example

TSTEP = 731T
STEP (FOURIER) = 755

Definitions

Argument Options Description
type <TIME, FOURIER>
TIME (Default)
The transient response is computed by time step integration in the time domain.
FOURIER
The transient response is computed in the frequency domain using the Fourier transform method.
option <SID>

No default
SID
Set identification number of a TSTEP Bulk Data Entry.

Comments

  1. A TSTEP entry must be selected to execute a transient analysis. TSTEP(FOURIER) is supported in both Direct and Modal Transient Analysis. Transient Response Analysis using Fourier Transformation via TSTEP(FOURIER) cannot be used in a model which also contains a Modal Frequency Response Analysis subcase. OptiStruct will error out in such cases.
  2. A TSTEP entry can also be used to execute a transient thermal analysis (only for type=TIME or default).
  3. For the application of time-dependent loads in modal frequency response analysis, a TSTEP Bulk Data Entry must be selected by the TSTEP(FOURIER) command. The time-dependent loads will be recomputed in the frequency domain by a Fourier transform.