Learning objectives
In this lesson
- Method selection follows behaviour and verified eligibility.
- Modal results require engineering interpretation.
Engineering explanation
A lateral-force procedure uses a prescribed distribution and limited dynamic description. Modal response spectrum analysis resolves multiple modes and directions. Nonlinear or time-history methods may be needed for behaviour simpler methods cannot represent, but require stronger input control and validation. First characterize regularity and dynamic sensitivity; then check explicit eligibility and combination rules in the adopted edition; finally validate participation, base reactions, torsion, drift, displacement and any required scaling.
Concept exercise
Which analysis method should I use?
Use these decision prompts, then verify normative eligibility in the adopted standard.
Simple regular response?
A simplified method is considered only if all eligibility conditions are satisfied.
Higher modes or torsion?
Use a method that resolves relevant dynamic contributions.
Nonlinear behaviour central?
Escalate to a validated advanced method and specialist review.
Key takeaways
What to carry forward
- Method selection follows behaviour and verified eligibility.
- Modal results require engineering interpretation.
- Forces and displacements must tell a coherent story.