adampar
Aerospace
- Jun 13, 2014
- 20
Hello eng-tips friends!
Today i realised that i don't know how to run a restart analysis in NX Nastran! The software is updated, so i work on Femap 11.2.2 with NX Nastran.
I wanted to run a prestressed frequency response model, so in order to do that i had to run a nonlinear modal analysis with stiffened modal enabled. Then, to
run a frequency response analysis with the modes of the preloaded model, a restart analysis was necessary. However, every single time, the eigenvalues were
calculated all over again and they were the modes of the original model (not the prestressed). After many efforts, i decided to go back to the basics,
so i performed once again the Femap example: Modal Frequency Analysis of the Hinge Model. I followed carefully all the steps described, but there seems to be
something wrong. When i restart frequency response analysis from the modal analysis I run (after extracting .DBALL and .MASTER files), i open the newly created .f06 file and
i see that the eigenvalues are calculated all over again (although i had calculated them in the modal analysis and the METHOD=1 exists in both .dat files)!!
On the other hand, when i restart from the pre-existing .DBALL and .MASTER files in the Femap database, open again the .f06 file and there is NO MENTION of eigenvalues calculation
which i assume means that the eigenvalues are not calculated again. Do i do something wrong or is it a Femap bug? I don't attach any files since the model exists in the Femap
directory and the steps are followed the same.
Any help would be valuable.
Today i realised that i don't know how to run a restart analysis in NX Nastran! The software is updated, so i work on Femap 11.2.2 with NX Nastran.
I wanted to run a prestressed frequency response model, so in order to do that i had to run a nonlinear modal analysis with stiffened modal enabled. Then, to
run a frequency response analysis with the modes of the preloaded model, a restart analysis was necessary. However, every single time, the eigenvalues were
calculated all over again and they were the modes of the original model (not the prestressed). After many efforts, i decided to go back to the basics,
so i performed once again the Femap example: Modal Frequency Analysis of the Hinge Model. I followed carefully all the steps described, but there seems to be
something wrong. When i restart frequency response analysis from the modal analysis I run (after extracting .DBALL and .MASTER files), i open the newly created .f06 file and
i see that the eigenvalues are calculated all over again (although i had calculated them in the modal analysis and the METHOD=1 exists in both .dat files)!!
On the other hand, when i restart from the pre-existing .DBALL and .MASTER files in the Femap database, open again the .f06 file and there is NO MENTION of eigenvalues calculation
which i assume means that the eigenvalues are not calculated again. Do i do something wrong or is it a Femap bug? I don't attach any files since the model exists in the Femap
directory and the steps are followed the same.
Any help would be valuable.