AD.2006-1002.1.1 Automatic calculation of the Response Spectrum as per IBC

STAAD.Pro previously allowed response spectra to be defined by the user, or calculated as per the Indian IS 1893 or Eurocode EC8.

The graphical user interface (GUI) has been enhanced so that it can now automatically generate a response spectrum as per the guidelines of the IBC/ASCE code

(*). This new feature saves users the time and effort involved in establishing the 1 second and short period accelerations indicated in the IBC/ASCE maps and then converting them into spectral data based on the equations provided in the code.

The user enters the latitude and longitude (or select a US zip code), STAAD.Pro then establishes the site coefficients, S1 and SS. The user then selects the appropriate site class (A-F) and with this information, STAAD.Pro calculates the MCE spectral acceleration and design spectral acceleration as per sections 11.4.3 and 11.4.4 of the ASCE7-05 code. Finally the design response spectrum will be generated based on section 11.4.5 of the ASCE7-05 code.

Note: There is no change to the input command structure.

Description

Go to the General | Load page and in the Load dialog box, open the Load Case Details and select the appropriate primary load case with the masses (defined as load items) defined or create a new primary load case and add the masses, if required. Click on the Add button which will bring up the Add New: Load Items dialog box. Select the Response Spectrum option from the list on the left.

With the code option set to Custom, a Generate IBC Spectrum button will now be available as shown thus

Click on the Generate IBC Spectrum button to open the Spectrum Parameters dialog box thus

Refer to Spectrum Parameters dialog for details on the input fields in this dialog.

To complete the generation of the IBC response spectrum pairs, click on the Close button. The completion of the Response Spectrum command continues as for all other Custom defined Response Spectrum commands. Note that the details of the spectrum Period, Acceleration pairs are displayed in the Response Spectrum window, but cannot be modified at this time.

For more details on the Response Spectrum loading command, refer to Section 5.32.10.1 of the Technical Reference Manual .