HROPT

HROPT, Method, Value1, Value2, Value3, Value4, Value5
Specifies harmonic analysis options.

Valid Products: Pro | Premium | Enterprise | PrepPost | Solver | AS add-on

Method

Solution method for the harmonic analysis:

AUTO

 — 

Automatically select the most efficient method (default). Either the full method (FULL) or the frequency-sweep method (VT) is selected, depending on the model. For Method = AUTO, Value1..Value5 are unused fields.

FULL

 — 

Full method. For Method = AUTO, Value1..Value5 are unused fields.

HBM

 — 

Harmonic Balance method. See Command Specification for Method = HBM.

HNLA

 — 

Harmonic nonlinear acoustics method (based on the FULL harmonic algorithm). See Command Specification for Method = HNLA.

KRYLOV

 — 

Frequency-sweep Krylov method. See Command Specification for Method = KRYLOV.

Note:  The Krylov approximation can be run using macros as customizable templates as described in Frequency-Sweep Harmonic Analysis via the Krylov Method in the Structural Analysis Guide. Alternatively, you can perform a Krylov solution without customization as described in Krylov Method Implemented using Mechanical APDL Commands in the Structural Analysis Guide.

MSUP

 — 

Mode-superposition method. See Command Specification for Method = MSUP.

VT

 — 

Frequency-sweep (Variational Technology) method (based on the FULL harmonic algorithm). See Command Specification for Method = VT or VTPA.

VTPA

 — 

Frequency-sweep (Variational Technology) perfect absorber method (based on the FULL harmonic algorithm). See Command Specification for Method = VT or VTPA.

If the solution method is not specified, the program automatically selects either the Full method or the frequency-sweep method, depending on which method is most efficient for the model. The frequency-sweep method uses the underlying Variational Technology method.

Command Specification for Method = HBM

HROPT, HBM, NH, --, --, --, --

Table 188: Semantic labels and definitions of Value1, ... Value5 for Method = HBM

Value HBM label and description
Value1

NH

 — 

Number of harmonics used in a harmonic balance method analysis. It must be an integer within the range 1 ≤ NH ≤ 30. Defaults to 1.

Value2, … Value5-- Unused fields.


Command Specification for Method = HNLA

HROPT, HNLA, SolType, --, --, --, --

Table 189: Semantic labels and definitions of Value1, ... Value5 for Method = HNLA

Value HNLA label and description
Value1

SolType

 — 

Type of harmonic nonlinear solver.

1

 — 

A single-source harmonic solver that provides nth harmonics (default).

2

 — 

Frequency-difference method. The frequency-difference problem arises when two waves interact at different frequencies, specified by the HARFRQ command as FREQB and FREQE for the first and second frequencies, respectively. The difference frequency is equal to the absolute value of (FREQB - FREQE).

Value2SolType = 1SolType = 2

NH

 — 

Number of harmonics used in a harmonic nonlinear acoustic analysis. It must be an integer within the range 2 ≤ NH ≤ 30. Defaults to 3.

-- Unused field.
Value3SolType = 1SolType = 2

nIter

 — 

Number of iterations used in the analysis. It must be an integer greater than 2. Defaults to 50.

-- Unused field.
Value4 and Value5-- Unused fields.


Command Specification for Method = KRYLOV

HROPT, KRYLOV, FRQKRY, --, --, --, --

Table 190: Semantic labels and definitions of Value1, ... Value5 for Method = KRYLOV

Value KRYLOV label and description
Value1

FRQKRY

 — 

Frequency at which the Krylov subspace is built. Defaults to the middle of the frequency range specified using the HARFRQ command. (FRQKRY is not supported for a distributed-memory parallel solution that uses frequency domain decomposition, DDOPTION,FREQ).

Value2, ... Value5-- Unused fields.


Command Specification for Method = MSUP

HROPT, MSUP, MAXMODE, MINMODE, MCFwrite, --, MCkey

For more details related to mode-superposition harmonic analyses, see Notes.

Table 191: Semantic labels and definitions of Value1, ... Value5 for Method = MSUP

Value MSUP label and description
Value1

MAXMODE

 — 

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

Value2

MINMODE

 — 

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

Value3

MCFwrite

 — 

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 Jobname.mcf.

YES

 — 

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

Note:  MCFwrite provides a singular (one-time) output of the modal coordinates. It will not provide the information for LSWRITE/LSSOLVE operations.

Value4-- Unused field.
Value5

MCkey

 — 

Modal coordinates output key to the .rfrq 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.rfrq. A subsequent expansion pass (EXPASS) is not supported.


Command Specification for Method = VT or VTPA

HROPT, VT, --, --, --, Damp, --

or

HROPT, VTPA, --, --, --, Damp, --

Table 192: Semantic labels and definitions of Value1, ... Value5 for Method = VT or VTPA

Value VT (or VTPA) label and description
Value1, Value2, Value3-- Unused fields.
Value4

Damp

 — 

Damping mode for frequency-dependent material properties (valid only for the frequency-sweep method, Method = VT).

Hysteretic

 — 

Not proportional to the frequency.

Viscous

 — 

Proportional to the frequency (default).

Value5-- Unused field.


Command Default

If you run a harmonic analysis (Antype = HARMIC or 3 on the ANTYPE command) and you do not issue HROPT, the default value is Method = AUTO.

Notes

Specifies the method of solution for a harmonic analysis (ANTYPE,HARMIC). For detailed descriptions of the various solution methods, see Overview of Harmonic Analysis Solution Methods in the Structural Analysis Guide.

If used in SOLUTION, this command is valid only within the first load step.

This command is also valid in PREP7.

For Method = MSUP:

For cyclic symmetry mode-superposition harmonic solutions, MAXMODE and MINMODE are ignored.

To include residual vectors in your mode-superposition harmonic analysis, specify RESVEC,ON.
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.

Menu Paths

Main Menu>Preprocessor>Loads>Analysis Type>Analysis Options
Main Menu>Solution>Analysis Type>Analysis Options