Moisture analysis has an equivalency with thermal analysis. So for hygro analysis, use some equivalent parameters and do a thermal analysis. If you do an uncoupled analysis, two separate analyses (thermo- and hygro-) may be done, the results of which may be fed to a mechanical analysis scheme. You may need little APDL coding. Please refer the book

The Finite Element Method and Applications in Engineering Using ANSYS® By Erdogan Madenci, Ibrahim Guven

Thanks a lot, Mr. Bennet !

I had earlier tried the approach that you have mentioned, i.e. feeding equivalent parameters to the standard thermal analysis. Unfortunately, the results did not match with any of the references. Maybe, I did make some mistake in any of the pre-processing steps. I shall double check it to see if this works.

Thanks again.

Warm regards,

Nitin

Are you performing a damped frequency analysis or an undamped analysis? It is very well known that in a dynamic analysis, moisture affects the damping capacity in composites and hence the dynamic analysis is affected to include hygrothermal effects.

For details, you may look at a NASA Technical Memorandum by Saravanos published in 1989. There is a formulation present in that document. It is possible that you may quickly code that up and use that approach rather than ANSYS to solve your problem or you may find leads to solve such a problem in commercially available FEM tools from some papers which cite that article.

Best!

Thank you very much, Mohit sir for your valuable suggestion.

To be exact, I am studying the vibro-acoustic responses (in frequency domain) of the composite panels subjected to hygro-thermal loading. Indeed, the damping capacity in composites is affected due to hygro-thermal loads. I am considering proportional damping which is dependent on the strucutral stifness matrix (that includes hygro-thermal effects) as well as the excitation frequency. I have also coded the problem using HSDT and was even able to validate the results. I wanted to see a comparison between the simulation results from commerical FEM tools and my model. That is exactly why I am looking for a way to see the hygrothermal effects on free vibration through ANSYS.

Thanks for pointing to the formulation given by Saravanos 1989.

Warm regards,

Nitin