I am looking at designing a metal backhoe boom, looking for strength and
minimal weight. Rather than using a structural steel beam, I am designing a
honeycomb metal box. As only three sides can be welded with the honeycomb
structure, the fourth side being welded to close the box, I have a question
about which three sides should be welded with the honeycomb structure.
Obviously the two sides (left and right), but should the third side be the
top which tends to operate in compression or the bottom which tends to
operate in tension. If it makes any difference, one boom has a slight taper
from end to end (side view), the other a bit of a curve, curving up in the
center of the length (once again the side view). Anyone know?

Rick