Question

Which method is used for structural analysis of indeterminate structures?

• A. Equilibrium method
• B. Virtual work method
• C. Force method
• D. Free body diagram

Hint:

The Force Method is especially useful for statically indeterminate structures where compatibility conditions are used in addition to equilibrium.

Answer 1

The Correct Option is C

Step 1: Understand the types of structures
A structure is indeterminate when the static equilibrium equations alone are not sufficient to determine all internal forces and reactions.
Step 2: Identify applicable analysis methods
For indeterminate structures, additional compatibility conditions (like deformation compatibility) must be considered. This leads to advanced methods like: - Force method (also called flexibility method)
- Displacement method (also called stiffness method)
Step 3: Evaluate the options
(1) Equilibrium method — applies only to determinate structures — Incorrect
(2) Virtual work method — used for deflection, not full analysis — Incorrect
(3) Force method — accounts for redundancy in indeterminate structures — Correct
(4) Free body diagram — a tool, not a method — Incorrect
Step 4: Conclusion
Therefore, the correct method for analyzing indeterminate structures is the Force method.