Variable Frequency Vibration testing is performed to evaluate the ability of parts to withstand vibration of varying frequency within a specified frequency range. This test simulates withstanding moderate to severe vibration as a result of motion produced by transportation or field operation. Vibration of this type may disturb operating characteristics, particularly if the repetitive stress causes fatigue.

For design purposes, a swept frequency sinusoidal test may yield more pertinent design information such as resonant frequencies and modes than a random vibration test. This test is considered to be destructive.