Response Spectrum sheet

Clicking the “Response Spectrum” sheet your screen should display something similar to Fig. 10. You will note three fields, i. e. “Frequencies” “Type of Response Spectrum”, and “Damping”. In the “Frequency” field you indicate the highest and lowest frequency of the response spectrum together with the stepwidth of response spectrum calculation. Note that SHAKYGROUND cuts down the upper frequency limit to a value corresponding to 1/6 of the digitization frequency. If you specify, for example, a digitization frequency of 200 Hz (see the “General” sheet) the uppermost possible value of the response spectrum will be 3313Hz. This limit has been introduced for reasons of numerical stability. You can rise this limit by choosing a higher digitization frequency together with a larger number of points of the synthetic seismogram. For more details about how to choose the digitization frequency and seismogram length see the paragraph concerning the “General” sheet.

The Response Spectrum Sheet.

The choice of the “Type of Response Spectrum” to be calculated is quite simple. Just click the box of your desired response spectrum type. Choose the damping value of the response spectrum using the box named “Damping” at the bottom of the sheet. The damping is understood in fractions of 1 instead of %. For a 5% response spectrum choose a value of 0.05 in the “Damping” box.