ABSTRACT
If we’re going to design structural systems to withstand earthquakes, wind, or other dynamic forces, we have to be able to calculate or estimate the natural frequencies of such systems as a central measure of their dynamic properties. Therefore, as engineers, we want to be able to estimate these fundamental frequencies as quickly and efficiently as possible. While modern computational techniques enable us to calculate such frequencies for very complex configurations, geometries, and loads, we always have reasons to do quick, meaningful “back of the envelope” calculations that confirm (or deny) our intuition, as well as provide a framework for interpreting and confirming complex computer modeling.
