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internal loads on a flexbody

Hello to everybody,
 
I need to calculate the internal loads, on several wing sections, arising during a flexible aircraft model landing simulation.
I've used the durability plugin to generate a .mdf file after the landing simulation, and, subsequently, I've run a restart simulation in Nastran (sol 112) . In order to retrieve the internal loads, I've defined a set of grids (AECOMP card), which define the downstream structure portion, and a reference monitor point (MONPNT1 card), where the resultant (integrated) bending an torsion moments acting on the structure portion are evaluated . The request to output the internal loads has been specified in the case control section of the restart file (MONITOR(IMAG)=ALL).
The monitor point technique has been adopted to evaluate the internal loads, since the FE model is a dynamic model  where the stiffness and the mass properties have been defined by means of matrices (DMIG), instead of conventional elements…
Unfortunately I don't find any output in the f06 (and no specific error/warning message)...I've tried to insert the AECOMP, MONPNT1 cards, alternatively, in the original Nastran file (the one used to generate the .mnf and the .master files), or in the restart file, but the results don't change...
On the contrary, I’ve tried to output the acceleration in some structure grids (specifying the XYPUNCH ACCE RESP card in the case control), and it works: only the integrated loads seem to be a problem to retrieve…
Anyone can help me?
Thank you very much in advance,
 
Francesco
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  • Thank you very much Sanjay​
    I see MONPNT3 output in the file e1msr2.f06. Unfortunately I believe that MONPNT3 doesn’t run if the grids which define the cut of your section (grid set in the MONPNT3 card) belong to a DMIG matrix (in the element set of the MONPNT3 card you need to define conventional elements and no DMIG matrices…). On the contrary, MONPNT1 card, which works with DMIG, is not compatible with SOL103 (first Nastran run). In your example, I don’t see MONPNT1 output in the file e1msr2.f06, even if you’ve defined it in the bulk data…
    Now the questions are.
    Do you know a way to use MONPNT3 with DMIG matrices ?
    How can you export MONPNT1 output in f06 (or punch files) after the restart procedure?
    Thank you in advance.
    Regards,
    Francesco
Reply
  • Thank you very much Sanjay​
    I see MONPNT3 output in the file e1msr2.f06. Unfortunately I believe that MONPNT3 doesn’t run if the grids which define the cut of your section (grid set in the MONPNT3 card) belong to a DMIG matrix (in the element set of the MONPNT3 card you need to define conventional elements and no DMIG matrices…). On the contrary, MONPNT1 card, which works with DMIG, is not compatible with SOL103 (first Nastran run). In your example, I don’t see MONPNT1 output in the file e1msr2.f06, even if you’ve defined it in the bulk data…
    Now the questions are.
    Do you know a way to use MONPNT3 with DMIG matrices ?
    How can you export MONPNT1 output in f06 (or punch files) after the restart procedure?
    Thank you in advance.
    Regards,
    Francesco
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