$
$     THIS ALTER IS CONFIDENTIAL AND A TRADE SECRET OF THE 
$     MSC.SOFTWARE CORP.  THE RECEIPT OR POSSESSION OF
$     THIS ALTER DOES NOT CONVEY ANY RIGHTS TO REPRODUCE OR
$     DISCLOSE ITS CONTENTS, OR TO MANUFACTURE, USE, OR SELL
$     ANYTHING HEREIN, IN WHOLE OR IN PART, WITHOUT THE 
$     SPECIFIC WRITTEN CONSENT OF THE MSC.SOFTWARE CORPORATION.                                
$

Alter to Calculate Interface Loads Across Superelement
Boundaries During Dynamic Analyses


Alter Name     sebloada.v2001


Purpose

Calculate dynamic superelement interface loads


Solution Sequences

SOL 108, 109, 111, or 112


Input
 
Executive Control

Include 'sebloada.v2001'.

Case Control

PARAM, SEBFORCE, n $ n = 1, 2, or 3 in superelement
subcase(s) where $ the boundary
forces are required.

SET m = id1, id2, id3,...

OLOAD = m $ SET m calls out list of boundary
GRIDs/SPOINTs.

The SEBFORCE parameter controls the type of output:

Value               Output

1       Printed/punched output per OLOAD request.

2       Same as 1 with DMIG entries of forces at grids sent 
        to the punch file too.

3       Same as 2 but with a DMI table of the output time 
        steps/frequencies sent to the punch file as well.

Use of a SET to limit the output to the boundary GRIDs and/or
SPOINTs is strongly recommended to avoid superfluous
output.  If OLOAD = ALL is requested, interface loads for
non-boundary DOFs are printed as zeroes for all output time
steps/frequencies.

OUTPUT(XYPLOT) $ (optional).

XYPUNCH OLOAD /grid_id(component) $ creates TABLED1
entries.

Use the OUTPUT(XYPLOT) section to create TABLED1
entries of the loadings at the grids/DOFs selected by the
XYPUNCH commands.

 
Bulk Data

No special Bulk Data is required.


Output

All superelement boundary load output starts AFTER the normal
output (DISPLACEMENTS, STRESSES, etc.) for a given
superelement.  The boundary loads are presented in a way that
resembles a normal OLOAD table output except that it occurs in an
upstream superelement.  A resultant vector of the entire boundary
load for each output time step/frequency is also printed.  Punched
DMIG entries of the loadings applied to the grids may be obtained by
setting PARAM,SEBFORCE,2.  To obtain a DMI listing of the output
time steps/frequencies in the punch file, set PARAM,SEBFORCE,3.


Limitations

The boundary loads calculations do not take into account any loads
applied to upstream boundary or interior grids.


Sample Files

sebload1.dat    A zero density cantilevered beam with a tip mass
model that allows the comparison of element forces
at the outboard end of the residual to the calculated
superelement boundary forces.


Additional Documentation

J. Swan, "A DMAP Alter for Interface Loads Across Superelement
Boundaries During Dynamic Analyses," 1992 MSC World User's
Conference Proceedings, Vol. 1, Paper No. 23, May 1992.