Example “TESTSAT/RUBY/EX27/readBdf.rb” illustrates the reading of superelements from a BDF file, and the identification of the superelements that have been read.
A NastranDb object is first examined, before reading the model from a BDF file:
db=NastranDb.new()
printf("db = %s\n",db.to_s)
printf(" db.SEID = %d\n",db.SEID)
printf(" db.refCounter = %d\n",db.RefCounter)
printf(" db.NbrSuperElements = %d\n",db.NbrSuperElements)
These instructions produce the following output:
db = DataBase: 0309CDD8 db.SEID = -1 db.refCounter = 1 db.NbrSuperElements = 0
As no model has been read, the number of superelements in the database is necessarily zero. SEID=-1, because the model is not yet “initialized” (read from a BDF or an OP2 file).
The output is different when our example model is read:
db=NastranDb.new()
db.readBdf(bdfPath)
printf("db = %s\n",db.to_s)
printf(" db.SEID = %d\n",db.SEID)
printf(" db.refCounter = %d\n",db.RefCounter)
printf(" db.NbrSuperElements = %d\n",db.NbrSuperElements)
These instructions produce the following output:
db = DataBase: 030BF618 db.SEID = 0 db.refCounter = 1 db.NbrSuperElements = 8
After reading the model, the SEID is set to 0, which means that “db” points to a master DB (corresponding to residual model). The master database contains 8 superelements.
The following instructions:
db2=db.getMaster()
printf("db2 = %s\n",db2.to_s)
printf("db2.class = %s\n",db2.class.to_s)
lead to the following output:
db2 = db2.class = NilClass
As “db” is a master database, the function “getMaster” returns a “nil” object.
On the other hand, the following instructions:
nbr=db.NbrSuperElements
(0...nbr).each do |pos|
printf(" pos = %d\n",pos)
id=db.getSuperElementIdFromPos(pos)
printf(" id = %d\n",id)
sdb=db.getSuperElementFromPos(pos)
if pos==3 then
sdb3=sdb
db2=sdb3.getMaster()
end
GC.start
printf(" sdb = %s\n",sdb.to_s)
printf(" db2 = %s\n",db2.to_s)
printf(" db.SEID = %d\n",db.SEID)
printf(" sdb.SEID = %d\n",sdb.SEID)
if db2 then
printf(" db2.SEID = %d\n",db2.SEID)
end
printf(" refCounter = %d\n",db.RefCounter)
end
produce information for the different superelement databases contained in the master database. For example, for pos=5, the output lines are:
pos = 5 id = 12 sdb = DataBase: 0312C6E0 db2 = DataBase: 030BF618 db.SEID = 0 sdb.SEID = 12 db2.SEID = 0 refCounter = 4
“sdb” points to the superelement at position 5 in the list of superelements. Superelement ID is 12. “db2” is the master database of superelement at position 3 in the list of superelements (fourth superelement as first superelement is at position 0). This means that “db2” points to the master database that has been read from the BDF file.
The database references counter is printed at several places in the script. This has been done to check and debug reference counting. It works as expected with ruby extension. Note however that reference counting management is a little more tricky with Python, .NET assembly and COM component. We made some tests to check these and believe there is no program leak related to reference counting.