TRNOPT
TRNOPT, Method,
MAXMODE, InitialAcc, MINMODE,
MCFwrite, TINTOPT,
VAout, DMPSFreq,
EngCalc, MCkey
Specifies transient analysis options.
MethodSolution method for the transient analysis:
FULL
—
Full method (default).
MSUP
—
Mode-superposition method.
MAXMODELargest mode number to be used to calculate the response (for
Method= MSUP). Defaults to the highest mode calculated in the preceding modal analysis.InitialAccKey to activate calculation of initial acceleration:
(blank)
—
Initial accelerations are not calculated (default).
INIL
—
Calculate initial acceleration for a full transient analysis using the lumped mass matrix.
MINMODESmallest mode number to be used (for
Method= MSUP). Defaults to 1.MCFwriteModal coordinates output key to the Jobname.mcf file (valid only for the mode-superposition method). To control how Jobname.mcf is written, specify options on the MCFOPT command.
NO
—
Modal coordinates are not written to Jobname.mcf.
YES
—
Modal coordinates are written to the text file Jobname.mcf (default).
TINTOPTTime integration method for the transient analysis:
NMK or 0
—
Newmark algorithm (default).
HHT or 1
—
HHT algorithm (valid only for the full transient method).
VAoutVelocities and accelerations output key (valid only for mode-superposition transient analysis):
NO
—
No output of velocities and accelerations (default).
YES
—
Write velocities and accelerations to the reduced displacement file, Jobname.rdsp.
DMPSFreqAverage excitation frequency (Hz) for the calculation of equivalent viscous damping from structural damping input (DMPSTR and MP,DMPS). See Damping for more details. Defaults to zero. If an excitation frequency is not specified, structural damping is ignored. If tabular excitation frequency data is provided in a full transient analysis (
DMPSFreqTabon DMPSTR), it supersedes this value.EngCalcAdditional element energies calculation key:
NO
—
Do not calculate additional element energies (default).
YES
—
Calculate damping energy and work done by external loads.
MCkeyModal coordinates output key to the .rdsp file (valid only for the mode-superposition method):
Notes
Specifies transient analysis (ANTYPE,TRANS) options. If used in SOLUTION, this command is valid only within the first load step. Use the TINTP command to set transient integration parameters.
To include residual vectors in your mode-superposition transient analysis
(Method = MSUP), specify RESVEC,ON.
For Method = MSUP,
MAXMODE and MINMODE are ignored after a
modal restart analysis where remote modal files usage (MODDIR) and residual
vector calculation (RESVEC,ON) have been activated.
Method = MSUP is not available for ocean loading.
By default in a mode-superposition transient analysis, reaction force
and other force output contains only static contributions. If you want to postprocess the
velocities, accelerations, and derived results (Lab = TOTAL, DAMP, or
INERT on the FORCE command), set VAout = YES to
activate velocity and acceleration output.
The calculation of additional energies (EngCalc = YES) is valid
only for the full solution method (Method = FULL). The
Jobname.ESAV file is always saved in this case. The numerical integration
for damping energy and work are consistent only if solution data are written to the database for
every substep (OUTRES,ALL,ALL, OUTRES,ESOL,ALL, or
OUTRES,VENG, ALL). For more information, see Damping Energy and Work Done by External Loads in the
Mechanical APDL Theory Reference.
This command is also valid in PREP7.
Product Restrictions
Additional product restrictions for the TRNOPT command are shown in the table below.
| Command Option Method | Available Products |
| FULL (DOF = Structural) | Pro | Premium | Enterprise | PrepPost | Solver | AS add-on |
| FULL (DOF = Temp) | Pro | Premium | Enterprise | PrepPost | Solver | AS add-on |
| MSUP | Pro | Premium | Enterprise | PrepPost | Solver | AS add-on |