Modal

Solve parametric or time-dependent problem using the eigenmodal method.

Syntax

model.sol(sname).create(fname,"Modal")

model.sol(sname).feature(fname).set(pname,pvalue)

Description

Operation feature. The following properties and values are accepted:

Table 6-48: Valid Modal Property/Value Pairs for the Modal Solver

Property	Value	Default	Description
analysistype	frequency | transient	frequency	Solve for frequency response or transient response.
clist	String array		Provide values for constants as input parameters using a string array; for the corresponding constant names, use cname.
cname	String array		Provide names of constants as input parameters using a string array; for the corresponding constant values, use clist.
control	String	user	Name of the controlling study step or "user" if the feature is controlled manually.
dampratio	scalar | numeric vector	0	Damping ratios for participating modes.
eigsol	solution object		Pre-computed eigenpairs (or other vectors) to be used in the modal analysis.
keeplog	on | off	off	Keep warnings in stored log.
loadfact	string | vector of strings	empty	Scalar function(s) for time and/or parameter dependent boundary conditions.
message	String		The log message from the last solution process.
modes	integer vector	all	Participating modes.
outsollinearized	du | u	du	Store the total solution (u) or deviation and linerization point (du), when analysistype=frequency and storelinpoint=off.
plist	scalar | numeric vector		Frequency list. Only applicable when analysistype has been set to frequency.
pname	vector of strings		Parameter names.
pout	plist | fraction | spread	plist	Use plist as it stands or modify in relation to the participating modes.
rtol	scalar	0.01	Relative tolerance. Only applicable when analysistype has been set to transient.
soltype	sol | solmat | mat	sol	Output only solution, solution and reduced matrices, or only reduced matrices.
storelinpoint	on | off	off	Whether to store the linearization point.
tlist	scalar | numeric vector		Time list. Only applicable when analysistype has been set to transient.

In addition, the following properties are available for exporting matrices and vectors:

Table 6-49: Valid Modal Property/Value Pairs for Matrix and Vector Export from the Modal Solver

Property	Value	Default	Description
AllL	on | off	off	All load vectors, frequency.
DPartSol	on | off	off	Damping matrix times particular solution, frequency.
Dr	on | off	off	Damping matrix, transient and frequency.
Dra	on | off	off	Damping ratio matrix, transient and frequency.
EPartSol	on | off	off	Mass matrix times particular solution, frequency.
Er	on | off	off	Mass matrix, transient and frequency.
Kr	on | off	off	Stiffness matrix, transient and frequency.
Kud	on | off	off	Stiffness matrix times ud, transient.
L	on | off	off	Load vector, transient and frequency.
Pm	on | off	off	Projection matrix, transient and frequency.
U0	on | off	off	Initial value vector, transient.
Udot0	on | off	off	Initial derivative vector, transient.

For frequency response analysis, nonconstant Neumann boundary conditions and constant Dirichlet boundary conditions are supported. The only allowed type of parameter-dependent Dirichlet boundary condition are those that can be written as a constant vector times a scalar function. The scalar function is specified via the property loadfact. For transient response analysis only constant Dirichlet boundary conditions are supported. Neumann conditions that can be written as a constant vector times a scalar function (which is specified via the property loadfact) are supported for transient response.

The property modes is index 0 based.

If pout is set to fraction the output frequencies are the ones in plist multiplied by the absolute value of the largest eigenvalue in eigsol (or some other fraction of the largest participating eigenvalue of eigsol). The purpose of this property is to be able to automatically compute the frequency response for reasonable frequencies. If pout is set to spread then plist is interpreted as an interval around each participating eigenvalue. For example, if plist is set to range(0.9,0.04,1.1) then each participating eigenvalue is multiplied by this list, and the resulting lists are concatenated into the plist that is used.

Removed Properties

Table 6-50: Removed Properties for the Modal Solver Sequence Feature

Property	Reason
Callblevel	Given by the solver sequence attribute feature.