What is the term for the turning force that is applied to a material or structure?

The term for the turning force applied to a material or structure is torsion. Torsion specifically refers to the action of twisting or rotating an object about its longitudinal axis, which creates shear stress within the material. This shear stress results from the applied torque, which is akin to a force that causes rotational movement.

In engineering and structural analysis, understanding torsion is critical when designing components like shafts, beams, and other structures that will experience twisting forces during operation. The assessment of torsion is essential to ensure that materials can withstand these forces without failing, which helps in creating safe and reliable designs.

In contrast, compression refers to forces that push outward on a material, tension refers to forces that pull on it, and bending involves the application of a moment that results in curvature in a beam or other structural element. Torsion is distinct because it focuses explicitly on the forces that create a twisting motion, making it the correct answer for this question.