agarmar
New member
- Apr 20, 2018
- 2
Hello Everybody!
I want to perform a random frequency response analysis for a part which has some Composite layers (modeled with CQUADS+PCOMPG cards)
To do that, first I create a 1G Frequency response (sol 111) and I add the RANDOM analysis to that through a RANDPS card with the psd curve according to RTCA DO-160.
I am interested to see the RMS stress plot, so for that I ask for the output STRESS(PLOT, REAL, CRMS)=ALL above the subcase level due to random analysis.
The problem comes when I want to plot the results
It looks like Nastran / Patran (MSC.Random) does not evaluate the RMS stress for the composite properties (PCOMPG), however it is capable to show the stresses in both cases (PSHELL & PCOMP) for each frequency in the frequency response.
I know that in older versions of Nastran was not possible to retrieve composite stresses in sol 111 or Random, but in the QRG of the version that we have (Nastran 2017.1), according to PCOMPG remark 6, it should be possible to calculate the stress in a random analysis.
Does anybody know, how to evaluate composite RMS Stress with MSC Nastran??
Thanks a lot
I want to perform a random frequency response analysis for a part which has some Composite layers (modeled with CQUADS+PCOMPG cards)
To do that, first I create a 1G Frequency response (sol 111) and I add the RANDOM analysis to that through a RANDPS card with the psd curve according to RTCA DO-160.
I am interested to see the RMS stress plot, so for that I ask for the output STRESS(PLOT, REAL, CRMS)=ALL above the subcase level due to random analysis.
The problem comes when I want to plot the results
It looks like Nastran / Patran (MSC.Random) does not evaluate the RMS stress for the composite properties (PCOMPG), however it is capable to show the stresses in both cases (PSHELL & PCOMP) for each frequency in the frequency response.
I know that in older versions of Nastran was not possible to retrieve composite stresses in sol 111 or Random, but in the QRG of the version that we have (Nastran 2017.1), according to PCOMPG remark 6, it should be possible to calculate the stress in a random analysis.
Does anybody know, how to evaluate composite RMS Stress with MSC Nastran??
Thanks a lot
