proppastie
Well-Known Member
Bruhn 73 has calculations and charts for various stiffener elements out of Aluminum. My design used bent .016 angle with flutes to allow curvature for ribs......shown is crude testing of the .016 angle and spread sheet of calculations....I had 3 different ends on the angle testing possible transitions to other structure......round end, Z stiffener ends ....an plain end pushing against the angle itself.
shown is setup.....sample photo buckled angle
bottom line where as chart and other calculations show 223-255 lb load for "stable cross sections" my results (unstable?) were 113 lb z stiffened end, ...45 lb round end.....68 lb plane angle end.
shown is setup.....sample photo buckled angle
bottom line where as chart and other calculations show 223-255 lb load for "stable cross sections" my results (unstable?) were 113 lb z stiffened end, ...45 lb round end.....68 lb plane angle end.
