DETECTION OF FATIGUE CRACKS IN FLEXIBLE GEOMETRICALLY NON-LINEAR BARS BY VIBRATION MONITORING

✍ Scribed by S.L. Tsyfansky; V.I. Beresnevich

• Publisher: Elsevier Science
• Year: 1998
• Tongue: English
• Weight: 199 KB
• Volume: 213
• Category: Article
• ISSN: 0022-460X
• DOI: 10.1006/jsvi.1998.1502

✦ Synopsis

The results of mathematical simulation of flexural vibrations of a geometrically non-linear cracked bar under external harmonic excitation are presented. It is shown, that thanks to the influence of elastic non-linearity of the crack, new non-linear properties which are impossible in the initial undamaged structure, appear in the system (self-excitation of subharmonic regimes, appearance of even-numbered harmonic components in frequency spectrum of 3/1 order superharmonic regime). By the utilization of these non-linear effects a new method for detection of cracks is developed. Unlike traditional procedures, the proposed method permits recognition of the legitimated response to non-linearity of the crack through interfering signals from the geometrical non-linearity of a bar.