Partial spectrum of non-stationary response due to uniformly amplitude modulated random excitations

✍ Scribed by T. Fang; T.-S. Zhang

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 675 KB
• Volume: 182
• Category: Article
• ISSN: 0022-460X
• DOI: 10.1006/jsvi.1995.0206

✦ Synopsis

In order to give some information about statistical properties in frequency domain, the partial spectrum of a non-stationary random response is defined and illustrated. With time t as a fixed parameter, the partial spectrum is uniquely determined by the time-dependent covariance function of the response, and vice versa. Different kinds of instantaneous power spectra, including the Page spectrum, the Wigner-Ville spectrum and the present one are reviewed. It is found that the present partial spectrum is more suitable for the non-stationary random response problem, since it provides reliable information right from the beginning of the response. The partial spectra of the non-stationary response of a time-invariant linear system subjected to uniformly amplitude modulated random excitations are readily obtained in closed form by the complex modal method.