NASTRAN Effective modal mass

[rakeshsarma]

Hello,

I am doing a normal modes analysis of a 3D wing. I used a modified version of input bdf file from cfd4aircraft.com. The file is attached herewith. I want to output the effective modal mass participation in the .F06 file. I added the line "MEFFMASS(ALL) = YES" in the case control data section. But NASTRAN does not print out the modal mass participation in the output file. Could anyone kindly help me where I am wrong? Thank you!

 

[Naffoussi]

Hi,

Replace the mefmass all line by this one and see if it print out the results in the .f06 file

MEFFMASS(PRINT,GRID=0,PARTFAC,MEFEM,MEFEW,FRACSUM,SUMMARY) = YES



Seif Eddine Naffoussi, Stress Engineer

http://www.Innovamech.com

33650 Martillac û France

 

[rakeshsarma]

Hi,
Thank you for the reply. I tried your suggestion, but it does not work. I am using a student 2013 edition. Might that be the reason?

 

[Tuw]

Hi,

I managed to run the input file directly and get the modal effective mass? Please see below picture.

Regards,
Tuw

 

[rakeshsarma]

Hello guys,

I figured out the problem with help from MSC Tech Support. It is actually a limitation with the student edition. This command needs to be put through Direct text input and Patran does not write out direct text input in .bdf file for student version. However, the same file does work when submitted directly to Nastran.