Hello!

I have a question about  sandwich core technique.
That is...

For example,
If I use  two set of  5mm nomex honeycomb core(10mm thick in total) to  make a sandwich panel,
is it  as strong as  a single 10 mm nomex honecomb core panel?
the  double 5mm sandwich has reasonable strength?
or the double 5mm sandwich is easy to break?


actually,
I want to build a curved sandwich panel.
I tried a 10mm thick  nomex honeycomb core at first,
but the 10mm thick core was too strong to bend.

 I wonder that if I use  a 5mm core,then laminate,bend  and add one more 5mm honeycomb core.
I mean,,  the sandwich is   CFRP>honeycomb core(5mm)>CFRP>honeycomb core(5mm)>CFRP.
If this idea is O.K. I will be able to build thick and strong curved sandwich panels.


Any advice,
I would be happy.

Thanks,







 

I agree with Warren, just want to clear up the following:

>  I wonder that if I use  a 5mm core,then laminate,bend  and add one more 5mm honeycomb core.

>using bended sandwich panel is not that good idea, I feel.

> loading on a bended CFRP>sandwich panel may cause  inside separation...

Do you want to laminate an essentially flat glass or carbon outer skin, bond a honeycomb core to this laminate, and THEN bend it into the final shape and apply more glass or carbon (and then another honeycomb layer and the second outer skin) to lock everything in place? Don't do this! Unless the curvature is very small this will stress and distort the sandwich. It will be impossible anyway if the final part is curved in more than one direction.

That's not "the way it's usually done".

Using two honeycomb layers separated by a thin glass or carbon barrier will certainly work. You can do this, but you need to laminate everything  in the final shape. Either in a mold, or on a plug.
The middle glass or carbon layer connecting the two honeycomb cores doesn't have to be thick and strong, being in the middle of a sandwich it will not contribute much to the strength, it is pretty much dead weight but it is still required. If you have problems laying a bigger honeycomb into or onto your part because it is curved too much you can try to use several smaller pieces and fill the gaps with a resin-microballoon mixture.