trnopt#

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

Specifies transient analysis options.

Mechanical APDL Command: TRNOPT

Parameters:
methodstr

Solution method for the transient analysis:

  • FULL - Full method (default).

  • MSUP - Mode-superposition method.

maxmodestr

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

initialaccstr

Key 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.

minmodestr

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

mcfwritestr

Modal 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 Jobnamemcf.

  • YES - Modal coordinates are written to the text file Jobname.mcf (default).

tintoptstr

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).

vaoutstr

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 to the reduced displacement file, Jobnamerdsp.

dmpsfreqstr

Average excitation frequency (Hz) for the calculation of equivalent viscous damping from structural damping input ( dmpstr and mp,DMPS). See Damping DMPSFreqTab on dmpstr ), it supersedes this value.

engcalcstr

Additional element energies calculation key:

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

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

mckeystr

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.

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 Work Done by External Loads

This command is also valid in PREP7.

Additional product restrictions for the trnopt command are shown in the table below.

This command contains some tables and extra information which can be inspected in the original documentation pointed above.