design response spectra are extremely useful to structural engineers.
These spectra are the basis for:
design displacements and forces in systems expected to remain elastic
Developing design forces and displacement systems that respond inelastically
- Evaluating response of equivalent elastic structure
elastic spectra can be obtained by several methods, which are:
of site specific ground motion time histories
spectra can be presented in several formats, depending on the needs of
the engineer and what information is being presented. Some of the most
common formats are:
acceleration vs. period
velocity vs. period
displacement vs. period
acceleration vs. spectral displacement (capacity design spectrum)
plots (Sa, Sv, and Sd vs. period)
any of the above (except the capacity design spectrum) can be plotted
versus frequency rather than period.
which effect elastic spectra include the damping ratio, site conditions,
and near fault ground motion effects such as rupture directivity.