NASTRAN Generation of the parametric model

SDT-visc Contents Functions

4.8 NASTRAN Generation of the parametric model

The viscoelastic vibration toolbox is distributed with a set of NASTRAN DMAP and sample files that are used to implement some solutions steps within the NASTRAN environment. The following parameters are used in those DMAP

ViNset	number of sets defining the element selections.
ViOut	type of desired output. 0 returns the full matrices of the linear combination. 1 returns a first order reduced model.
ViSet1	ID for the first set. Sets are assumed to be written in sequential order.
ViIOSET	ID for set containing the list of nodes that need to be saved for input/output calculations.
ViShift	Frequency shift used to handle cases with rigid body modes. By default the shift is the complex double precision number 10.

fo_by_set

The objective of this DMAP (fo_by_set.dmp associated with sample job file vfirst_step12.dat) and the associated fevisco WriteStep12 and BuildStep12 commands is to generate a first order reduction of a model where parameters are coefficients on the stiffness matrix of elements within a given selection (NASTRAN set).

nas_sdtserv

This is used to overload basic SDT functionality through NASTRAN calls. You must first set local preferences

sd_pref('set','SDT','ExternalEig', ... % Callback used by fe_eig method 50
 'mode=fevisco(''nastran eig'',m,k,model.DOF,opt,model,Case);');