RAM Frame is capable of performing a dynamic response spectrum analysis, utilizing tables of ground motion response spectra curves. The tables supplied with the program contain the values from the NEHRP and UBC Normalized Response Spectra curves and the El Centro Earthquake Response Spectrum curve. For NEHRP and UBC, one table is provided for each soil type (S1, S2, and S3).

Response Spectra table selection is made when the data for the Dynamic Response Spectra load case is defined in RAM Frame.

Files of Response Spectra curves to be used by RAM Frame may be created and modified by the user. The file must be edited using a simple text editor, not a word processor that embeds control characters into the file. Use spaces, not tabs, between data items. The file name must have the extension .RSP.

The file has the following format:

Any number of lines at the beginning may be used as comment lines. These are indicated by double backslash, \\, at the beginning of each comment line.

Each subsequent line has the following format:

Period Accel

where:

Period

the period, in seconds

Accel

the Spectral Acceleration corresponding to the period. It may be the normalized value.

The values should be in order of increasing period. There should be a pair of values sufficiently large for whatever magnitude of structural periods may be encountered.

\\NEHRP Normalized Response Spectra
\\Damping = 0.05
\\ Soil Profile Type S1
0.00    1.00
0.02    1.00
0.11    2.50
0.40    2.50
0.50    2.00
.
.
.
2.63    0.27
2.75    0.24
2.88    0.22
  99    0.22