Energy Methods MCQ with answer and solution

Concept

Alternative name for flexibility method

Formula

NONE

Step-by-step solution

1. Structural analysis methods are classified into force and displacement methods based on primary unknowns. 2. In the flexibility method, redundant internal or support forces are selected as the primary unknown variables. 3. Since forces are solved first, the flexibility method is also known as the Force Method. Answer: D

Explanation

The flexibility method uses redundant forces as the unknown primary variables to solve indeterminate structures, which is why it is also called the force method. In contrast, the stiffness method uses joint displacements as primary unknowns and is called the displacement method. By satisfying compatibility conditions, the flexibility method determines the unknown internal or external forces.

Why the other options are wrong

A) Energy methods refer to energy-based analysis principles, not specifically the flexibility method. B) The equilibrium method is another name for the stiffness or displacement method. C) The displacement method uses joint displacements as primary unknowns, whereas flexibility uses forces.

Shortcut

Flexibility Method = Force Method; Stiffness Method = Displacement Method.

Common mistake

Confusing the flexibility (force) method with the stiffness (displacement) method.