The Spectrum Definitions tab is available when Earthquake (spectrum), Relief Loads (spectrum) and Water Hammer/Slug Flow (spectrum) are selected for Analysis Type in the Dynamic Analysis window.
The Time History Definitions tab is available when Time History is selected for Analysis Type in the Dynamic Analysis window.
Spectrum Definitions
One analysis may have multiple spectrum types and definitions. Predefined spectra are included in the spectrum definition list. Any combination of these predefined spectra can be used as is, deleted, or used with any other defined spectra.
You can include the basic spectrum data definitions in the comments for each ASCII spectrum file. Select Cmt to create a comment line. For more information, see Enter/Edit Spectrum Data and Examples.
Spectrum Data Files
Special force spectrum data files are created by the DLF/Spectrum Generator. The response spectrum table values are entered directly or saved as a file. Data stored in a file can be used by any analysis.
When using a file created by DLF/Spectrum Generator 
, you must specify the type of data which contained in the file, because the file
only contains a table of data points. This data is always frequency versus force-multiplier
with linear interpolation. A typical definition is in this format:
|
|
Range |
Ordinate |
Range Interpol |
Ordinate Interpol |
|---|---|---|---|---|
|
#TESTFILE |
FREQ |
FORCE |
LIN |
LIN |
The data in this file may also be read in directly using Enter/Edit Spectrum Data 
. In this case, omit the "#" from the spectrum declaration. For more information,
see Enter/Edit Spectrum Data.
Time History Definitions
Time history profiles are defined in a way similar to the definition of response spectra. The profile must be given a name, time versus force data definitions, and interpolation methods. Response spectra data must also be defined directly or from a file. The profile data may be entered with actual forces or normalized to 1.0, depending on how the force sets are defined.
One force-time profile should be defined for each independent point load on the piping system. The load case consists of one or more force profiles. Multiple force profiles can create a staggered loading on the system.