Seismic Analysis of Structures: Improvements Due to Probabilistic Concepts - Dynamic Behavior of Concrete and Seismic Engineering - page 287

For example, the bandwidth of the response of a one-random noise harmonic
oscillator is:

1/ 2

į = 4İ/ʌ

[8.25]

Figure 8.5. Wide-band (a and b) and narrow-band
(c and d) processes PSD and time rate

8.4.5.2. Envelope of a narrow-band process
A narrow-band process consists of both amplitude and frequency-modulated
frequency f 0 oscillations. The amplitude modulation gives conditions for the analysis
of extremas. It can be represented by a new process, whose envelope can be defined
by:

2 2

> @

2 2

E t X t dX/dt (t) / 2ʌf

[8.26]

0