adhesive design for skin to honeycomb core bonding in sandwich structu 1

[engroma]

Hi

I have to select an adhesive for skin to honeycomb bonding.
I have been thinking of comparing the lamina FEA stess results with adhesive mechanical properties.
I wonder if that is the right way to go ahead.
Do you know whether there is a standard calculation procedure to predict the stress applied on the interface between the lamina and the core?
Do you know any paper or book references about that?

Thanks

Regards

 

[RPstress]

The adhesive properties are less relevant than the core strength. Usually a well bonded panel will fail the core in shear rather than the adhesive. (In practice the bond between the honeycomb and skin sometimes fails before the core, but this is usually because of a shortcoming in manufacture. A well bonded panel will fail the honeycomb first.)

For sandwich panel design see the Hexcel document at

http://www.hexcel.com/NR/rdonlyres/...B3-7EFF685966D2/0/7586_HexWeb_Sand_Design.pdf

and the Diab one at

http://www.diabgroup.com/europe/literature/e_pdf_files/man_pdf/sandwich_hb.pdf

are good basic references. See also

http://www.hexcel.com/NR/rdonlyres/...-CC15967A4B05/0/4547_Sandwich_Fabrication.pdf

for additional background and

http://www.hexcel.com/NR/rdonlyres/...7D8B547CA/0/HexwebAttributesandProperties.pdf

The latter is the modern version of their classic TSB 120 document.

Zenkert "An Introduction to Sandwich Construction" is probably about as standard a reference as you'll get in a textbook, though Tom Bitzer's "Honeycomb Technology" is also referenced in the Hexcel document. An earlier book by Howard G. Allen "Analysis and Design of Structural Sandwich Panels" is also very worthy, if out of print.