Design of structures by a splitting method

A simplified method for the design of multi-spar wing boxes is presented. In typical multi-spar wing boxes the spars divide the boxes into cells. In the method presented these are analyzed individually, with adjacent cells taking their share of the stiffnesses of the common spar wall. This splitting method yields a design method that is computationally much quicker than designing a complete wing box, because each cell is considered separately from the others, except for linking between their design variables. The critical buckling load factor of the assembled structure when designed in this way will usually exceed the design load factor and otherwise will be equal to it, i.e. the design is guaranteed to be conservative.