To calculate the floor spectra from time history
acceleration, use the following procedure.
This procedure
should only be used if a time history load case is being solved by the analysis
engine.
Note: The floor response spectrum command must immediately follow an
analysis command. Therefore, it is helpful to select the corresponding analysis
command prior to starting this procedure.
Note: That analysis can only contain a single time history load case.
This command is used to specify the
calculation of floor and/or joint spectra from time history results. Note: This requires a STAAD.Pro Advanced Analysis license.
-
Either:
-
select the
Analysis page
- on
the
Analysis and Design ribbon tab, select the
Analysis Commands tool in the
Analysis Data group
The
Analysis/Print Commands dialog
opens.
-
Select the
Generate Floor Spectrum tab.
-
For every group and direction that is necessary:
-
Check one or more global directions in a table row:
GX,
GY, and
GZ.
-
Type a
Title used to identify the spectrum.
-
Use the drop-down to select the
Node Groups which are included in this
direction.
You may include as many directions as needed.
- Optional:
Type frequency options to use for the spectra (all are optional
inputs):
-
Type the
Lowest Frequency (in Hz) to be in the
calculated spectrum.
This should be at least 0.0 Hz.
-
Type the
Highest Frequency (in Hz) to be in the
calculated spectrum
-
Type the number of
Frequency Interval to use between the
lowest and highest frequency.
- Optional:
Type up to ten
Damping Ratios to use as a ratio.
(e.g., 3% damping is
0.03)
One spectrum will be generated for each damping ratio for each
global direction requested for each floor defined. The spectrum will be based
on these damping ratios. Is not entered, the default of 5% (0.05) damping will
be used as a single damping ratio.
-
Check the
Relative Acceleration? option if there is
ground motion defined and you wan tthe spectrums based on the relative
acceleration of the floor to the ground acceleration.
Otherwise, the acceleration is assumed to be an absolute
acceleration.
- Optional:
Select the print parameters as needed (both are optional):
-
Check the
Print Time History Acceleration used?
option to include this in the output.
-
Check the
Print Calculated Spectrum? option to
include this in the output.
-
Select the
Print Option you want to use.
-
Click
Add.
Tip: The
After Current option is helpful to make sure
this is added immediately following the analysis command if you selected prior
to this procedure.
The generate floor spectrum command is added
to the input file.