Guralp Systems ART - Manual (Page 49)

User guide
3.2.20 Drift spectra
This function has two behaviours depending on whether a
single or multiple time-histories have been selected. The
windows produced can be saved in different graphical formats
(.bmp, .eps, .jpg, .png or .tif) using the ‘Save figure’
option on the ‘File’ menu and printed using the ‘Print figure’
option the ‘File’ menu. The figures are either displayed in
colour or in monochrome depending on the option selected by
the user within the ‘Options’ window. The options used to
create the figure can be changed within the ‘Options’ menu
located at the top of the window.
Single time-history selected
Clicking on this button when only a single time-history has
been selected calculates and plots the drift spectrum (e.g.
Iwan, 1997) of the currently selected time-history for the
selected damping level and material type and periods between
0.5 and 15s (see below). This calculation can take many
seconds for a long time-history. The method given in Wang
(1996) is used to calculate the spectra. The spectra are
displayed in terms of percentage of maximum inter-storey drift.
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