What effect does the thrust force of a propeller have on the propeller tips?

The thrust force generated by a propeller exerts a significant effect on the geometry of the propeller blades, especially at the tips. When a propeller produces thrust, the aerodynamic forces acting on the blades induce bending. Specifically, the thrust force tends to cause the blades to flex forward at the tips, which is a result of the pressure distribution and airflow over the blade surface during flight.

As the propeller rotates, the combination of thrust and centrifugal forces creates complex load distributions; however, it is the thrust that principally contributes to the forward bending at the tips. This bending must be accounted for in the design and structural engineering of propellers to ensure they maintain performance, stability, and safety at various operating conditions.

The other options suggest different bending behaviors or load effects that do not accurately reflect the physical reaction of the blades to thrust. The forward bending due to thrust is a critical factor for engineers and designers to consider while optimizing propeller performance and ensuring longevity under operational stresses.