Seismic Analysis of Structures: Improvements Due to Probabilistic Concepts - Dynamic Behavior of Concrete and Seismic Engineering - page 317

Figure 8.20. Adjustment attempt of a 15-equivalent oscillator set
to represent the frequency stretching due to shocks
8.8.5.1. Modeling of a 1-dof-shock oscillator owing to a random parameter linear
oscillator
Let us take the case of an oscillator stimulated by a *(t) wide-band noise (quasi-
random noise) and study its stationary response.
The general principle results from the observation of the response signal
obtained by numerical simulation. The latter consists of amplitude and frequency
oscillation sequences randomly distributed (Figure 8.21).
If the maxima (most of the time corresponding to contact with the stops) are
transferred into an amplitude/frequency diagram, the points are organized along a
curve that characterizes a deterministic relationship between the frequency and the
amplitude (Figure 8.22).