I am trying to work out the allowable longerons loads on a four longeron plywood box type fuselage. There are no diagonals just 4- longerons, verticals (spaced every 25 inch or so), and a plywood shear web.
Can one assume that the longerons can take nearly their ultimate compression load without buckling (irrespective of vertical stiffner spacing) as they are braced in both directions by plywood shear webs.
In a truss type fuselage of course you would consider the longeron column length to be the vertical stiffner spacings but what about in the plywood box case?
The reason I ask is working backwards from the volksplane design it appears that the longerons would be inadequate if one considers column buckling between the vertical stiffners.
Any help would be appreciated.
Can one assume that the longerons can take nearly their ultimate compression load without buckling (irrespective of vertical stiffner spacing) as they are braced in both directions by plywood shear webs.
In a truss type fuselage of course you would consider the longeron column length to be the vertical stiffner spacings but what about in the plywood box case?
The reason I ask is working backwards from the volksplane design it appears that the longerons would be inadequate if one considers column buckling between the vertical stiffners.
Any help would be appreciated.