trnopt

Mapdl.trnopt(method='', maxmode='', minmode='', mcfwrite='', tintopt='', vaout='', dmpsfreq='', engcalc='', mckey='', **kwargs)

Specifies transient analysis options.

APDL Command: TRNOPT

Parameters
method

Solution method for the transient analysis:

FULL - Full method (default).

MSUP - Mode-superposition method.

VT - Variational Technology method. (Removed by V18.2)

maxmode

Largest mode number to be used to calculate the response (for Method = MSUP). Defaults to the highest mode calculated in the preceding modal analysis.

minmode

Smallest mode number to be used (for Method = MSUP). Defaults to 1.

mcfwrite

Modal coordinates output key to the .mcf file (valid only for the mode-superposition method):

NO - No output of modal coordinates (default).

YES - Output modal coordinates to the text file Jobname.MCF.

tintopt

Time integration method for the transient analysis:

NMK or 0 - Newmark algorithm (default).

HHT or 1 - HHT algorithm (valid only for the full transient method).

vaout

Velocities and accelerations output key (valid only for mode- superposition transient analysis):

NO - No output of velocities and accelerations (default).

YES - Write velocities and accelerations on the reduced displacement file

Jobname.RDSP.

dmpsfreq

Average 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 (DMPSFreqTab on DMPSTR), it supersedes this value.

engcalc

Additional element energies calculation key:

NO - Do not calculate additional element energies (default).

YES - Calculate damping energy and work done by external loads.

mckey

Modal coordinates output key to the .rdsp file (valid only for the mode-superposition method):

AUTO - Writing depends on the modal analysis settings of the MXPAND command (default).

YES - Always write the modal coordinates to the file Jobname.rdsp. A subsequent expansion pass (EXPASS) is not supported.

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.

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.