Calculation tab

On the Calculation tab, several calculation options can be changed.

Integration

As the integration method, there are choices as follows;

• FFT (in frequency domain): integrates in the frequency domain using the Fast Fourier Transform (FFT).
• Seismograph simulation: integrates by simulating traditional seismographs.
• Trapezoidal rule: integrates based on the trapezoidal rule with the linear baseline correction of velocity.

[Low-cut frequency] needs to be set if [FFT] is selected. The natural frequencies and damping ratios of the velocity sensor and the displacement sensor must be specified if [Seismograph simulation] is selected.

Fourier analysis

In the Fourier analysis, analyzing time can be selected as [Time scope] from the followings;

• All time of record: analyzes all time of the record.
• Specified time: analyzes the time range specified by [Start time] and [Time length].
• Sync with waveforms: analyzes the time range same with waveforms.

Specifying the [Width of Parzen window] is necessary in all cases. In addition, the start time and time length for analysis are required if [Specified time] is selected.

Further information is given in Section 5.6.

Response spectrum

For response spectrum, the following parameters are needed.

• Damping ratio: sets the damping ratios for Sa, Sv, Sd and pSv in the [Resp.] textbox, and for Ve in the [Energy] textbox
• Number of periods: sets the number of periods to be calculated.
• Period range: sets the calculation period range by the [Lower] and [Upper] periods.
• Divide period geometrically: divides period geometrically if checked. Otherwise arithmetically.