THE EFFECT OF MODAL COUPLING IN RANDOM VIBRATION ANALYSIS

✍ Scribed by T. DAHLBERG

• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 223 KB
• Volume: 228
• Category: Article
• ISSN: 0022-460X
• DOI: 10.1006/jsvi.1999.2409

✦ Synopsis

When modal analysis techniques are used to determine spectral densities of the responses of distributed-parameter linear mechanical structures subjected to stationary random excitation, a summation of all modal spectral densities (both direct-and cross-) should be performed. A very common textbook recommendation is that the modal cross-spectral densities may be neglected if certain conditions are satis"ed. In this paper that recommendation will be discussed. Using a simple example the in#uence of modal cross-spectral densities on the spectral densities of some responses of a simply supported beam will be investigated. Response standard deviations will be determined and the importance of the modal cross-spectral densities in some frequency ranges, covering also resonance frequencies of the beam, will be demonstrated. Special interest is devoted to extreme values of some response processes.