Consider a large ID fan running at 990 RPM (16.5 Hz). A Festfrequenzprüfung reveals a constant 49.5 Hz vibration—exactly the 3rd harmonic. By locking a shaker to 49.5 Hz and measuring the bearing housing response, engineers discover that while the structure isn't resonating at 16.5 Hz, it is resonating at the 3rd harmonic. The fix? Add a stiffener at the 49.5 Hz antinode.
Test von Elektronikmodulen auf Dauerhaltbarkeit gegen motorinduzierte Schwingungen. festfrequenzprüfung