Basic Aeronautics

[Brian Clarey]

Structures in brief.....We had to come to this, so I will try to keep it from being a cure for insomnia. Basically, the forces on a structure are....Tension. compression and torsion twist. The perfect structure is a cube. The sides (Diaphragms) makes for a perfect structure due to all sides being structural and therefore bracing one another. As an illustration of this, if you take a shoe box , minus the lid it will be seen that the box is quite flimsy, in all three forces, particularly in torsion!! However, If the lid is fitted and secured all around, it becomes a complete structure. Now imagine that box being the cockpit of an aircraft ....attach the power unit at one end, the tail group at the other end,the wing on top and the undercarriage underneath. All loads are fed into the box. All very good till you put doors and windows into box. In a model with the wing removable, that of course allows access inside. With the wing refitted and adequately secured once again, the structure is complete. With an open ,structure, (stick) all open areas must be diagonally braced or sheeted.


Brian C