Aspects of the acoustic testing of an electronic system-Part II Acoustic versus vibration testing

摘要

In this paper, the second of three parts, the vibratory responses excited in an electronicrndevice during a vibration test, and an acoustic test are compared. It was found that thernresponses differ significantly for items mounted on vibration isolators. Under certainrncircumstances (stiff mounting of the elements in the device and for a certain vibrationrnaxis) a higher similarity can be noted between the vibration and acoustic tests. Due tornthe lack of excitation above 2000 Hz during the vibration testing, failures caused byrnexcitation in this range are not detected (significant for small components). Thernhigher responses in the low frequency range during the vibration test can inducernunrealistic failures. Application of the vibration test separately for individual axes asrnopposed to the distributed loading applied during the acoustic test can result inrnundetected failures also.