Hot wet consequences on aircraft interior sandwich panels

[jokerbenj]

Dear forum members,

I need your help regarding the effect of hot wet conditions on sandwich panels. This is an investigation reguested by the aviation authority. They would like to know how much the strength is affected if an interior component (installed in a medical rotorcraft) is in bad environmental conditions for a long time.
My panels are painted and are made of E-glass laminates with a Nomex core cured with phenolic resin.
I do not have time and money to perform complicated and long test, so I would like to find a way (books, comparison) to measure the effect of hot-wet conditions on my assembly.

Does someone have some references or experience on that area?

Thanks in advance for your valuable help
Regards,
Benjamin

 

[SWComposites]

Hot/wet conditions tend to reduce strength; specific reductions depend on the materials and temperature.

Does the material supplier have any hot/wet data for the glass/phenolic?

Where did you obtain the material allowables for the glass/epoxy and core materials? I suspect that the authority (FAA?) will want the same level of allowlables at hot/wet as you have already used.

What is your hot design temp? 130F? 180F?

Unfortunately there is no phenolic data in Mil-Handbook-17.

 

[jokerbenj]

Hello SWComposites,

The manufacturer does not have any value for that. I will use the DO-160F (equipments) conditions, because this is an interior component.
The authority (EASA/ENAC) need some proof. From the MIL-HDBK-17-2F chapter 6 , I can find some comparison values (ratio around 1.7) but this is only a laminate, and it does not take into account the "sandwich" property of my panel.
I guess I will have to do someday specific tests, but now, I will have to find an analytic way forward!