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Alter to Append Eigenvalue Solutions


Alter Name    appenda.alt


Purpose

To append eigenvalue solutions.


Solution Sequence

SOL 103.


Input
 
File Management Section

RESTART  - This run should be a restart from a previous run.

ASSIGN MASTER=old_data_base  $ to attach the existing solution to the run.
 
Executive Control

Include 'appenda.alt'.
 
Case Control

METHOD entry pointing to the new eigenvalue solution
method.
 
Bulk Data

EIGR or EIGRL is referenced in Case Control.  This entry
should have the new frequency range to be found.  For
example, if the initial run finds modes between 0.0 and 10.0
Hz and it is desired to append modes from 10.01 to 20. Hz,
then the range on the new entry is from 10.01 to 20.0 Hz.

PARAM,APPEN,xx where xx is the version in the database
containing the old eigenvalue solution onto which the new
eigensolution is to be appended.  (Note:  APPEN does not
need to match the RESTART version.)


Output

Standard eigenvalue solution output with the following modifications:
 
The eigenvalue summary table resulting from the new solution
is printed out as usual.
 
Messages informing the user that the appending is being
performed.
 
A new eigenvalue summary table listing all the eigenvalues
(the original plus the new solution) found.
 
Standard data recovery for the modes (including the original
set).


Limitations

The DMAP is implemented only for the residual structure solution.  It
does not work for individual superelements (although that feature
could be implemented by using a similar DMAP in subDMAP SEMR3
where the component modes are calculated).

This DMAP simply appends one eigenvalue solution onto another, so
there is no checking for missed or duplicate modes. 


Sample Files

append1.dat   Initial eigenvalue solution finding modes from 0. to 10.
Hz of a cantilever beam.

append2.dat   Restart run calculating modes from 10.01 to 20. Hz
and appending them onto the initial solution.

Additional Documentation

T. Rose, "Some Suggestions for Evaluating Modal Solutions," 1992
MSC World Users' Conference Proceedings, Vol. 1, Paper No. 10,
May 1992.