User`s guide

Release 7.5 MADYMO Coupling Manual

– Allocating more nodes than available CPU’s.

– Bad network connections

– Wrong MPI version (especially for Linux)

– Sending large amounts of data over the coupling interface

If in doubt, please contact your local support ofﬁce. For direct coupling, note that MA-

DYMO does not use any MPI calls, so any problems caused by it can best be handled by

the PARTNER support ofﬁce. For MPP coupling the logging of MADYMO and PART-

NER are separated. When MPP coupling calculations fail, ﬁrst check the available log-

ging and contact the support ofﬁce of the party that aborts the calculation.

• When the user is in doubt if the coupling is having a bad impact on the performance,

please run the coupled executable as if it was a stand-alone executable. All coupled exe-

cutables provided by PARTNER, can be run in stand-alone mode. By disabling coupling

(both in keywords in the input deck and command line options), all inﬂuences of the

coupling interface are removed and the most objective comparison between coupling

and standalone can be made. Please keep in mind that for best comparison, all MADY-

MO data must be replaced by the PARTNER counterparts.

1.5 Limitations and Known Issues

• Restarting a coupled simulation is supported with Radioss and LS-DYNA in direct cou-

pling. MPP coupling supports restart for LS-DYNA and MPP-DYNA, the latter with

madymo running on one cpu.

• In direct coupling, the PARTNER program sometimes writes "NORMAL TERMINA-

TION", even when MADYMO terminates abnormally.

Therefore the user is advised to check the following messages after running a coupled

simulation:

– In the screen output

, PARTNER writes "NORMAL TERMINATION" (or a similar

message) if no error appears on the PARTNER side.

– The message: "MADYMO TERMINATED NORMALLY" must appear in the log ﬁle

and reprint ﬁle.

• For extended coupling, it is required to send at least one element from PARTNER to

MADYMO. It is not allowed to send only nodes.

• Planes attached to a body are incorrect positioned if the center of gravity is nonzero.

• When performing an SMP-MPP (direct coupling) job, the output to standard out (typi-

cally the screen), and therefore the MADYMO log ﬁle, can be out of phase. This is normal

behavior. On some systems, this behavior can be changed, see the MPI documentation

for more information.

Not all partners write there output such that it ends up in the log ﬁle