Which of the following loads is NOT typically associated with wing structures?

Wing structures are primarily designed to handle various types of loads during flight. Tension loads are created when forces pull the structure, often during maneuvers or when the aircraft is subjected to lift. Bending loads occur as a result of aerodynamic forces acting at the wing's center of lift, causing it to flex. Shear loads are associated with vertical forces acting on the wing, particularly in turbulent conditions or during turns, and these forces help determine how the wing transmits loads to the fuselage.

Friction loads, on the other hand, are not typically a primary concern when discussing the structural loads of wings. These loads are more relevant in areas such as landing gear or movable control surfaces, where components slide against each other or where parts are in contact due to motion. The design and engineering of wing structures focus more on how they can cope with the tension, bending, and shear loads that result from the forces experienced during flight, making friction loads less relevant in this context.