Internal loads include which of the following?

• A. Compression
• B. Eccentric
• C. Torsional
• D. Shear

Answer: (A)

Internal loads are the forces carried through a member that produce stresses in its cross-section. The simplest and most direct internal load is an axial load along the member’s length, which creates normal stress and tends to shorten the member when it’s compressive. An off-center, eccentric load isn’t a pure axial internal load; it introduces bending in addition to axial effects. Torsional loading twists the member, producing shear stresses from torque, which is a different mode of internal action. Shear describes internal sliding between layers, another distinct stress state. Because compression directly represents an axial, normal-stress-causing internal load, it’s the best match.