What describes axial load?

• A. Load is imposed through the center of the material.
• B. Load is imposed off center, causing a material to want to bend (think cantilever).
• C. Load is imposed in such a way that causes a material to twist.
• D. The stress that causes a material to flatten or crush.

Answer: (A)

Axial load is a force that acts along the length of a member, passing through its centerline so the load works straight along the axis. This produces uniform normal stress across the cross-section and tends to shorten or lengthen the member without inducing bending moments or torsion. When a load is applied off-center, it creates a bending moment and the member tends to bend; a twisting action comes from torque about the axis; and compression is a general form of loading that reduces dimensions but axial load specifically refers to the through-center, along-axis action. That through-center description best captures axial load.