Comparison of Laboratory Testing Techniques for Airborne Store's Dynamic Response to In-ight Environmental Conditions

摘要

The paper presents a study of the vibrations that develop on innercomponents of a weapon system in captive ight, and their replicationvia mechanical vibration and acoustic tests. The goal of the study wasto examine which testing method is more suitable for predicting ightloads, to examine dierent excitation methods, and to dene the draw-backs and limitations of each testing approach. This should eventuallylead to a testing methodology (or a combination of analyses and tests)that should lead to a good prediction of in-ight loads with reduction inthe number of ight tests, and avoiding structural components redesign.For this, mechanical vibration tests and acoustic tests were conductedon a weapon system, using various excitation methods, and the result-ing component loads were compared to those measured in captive ight.It was found that mechanical vibration tests are suitable for generatingthe load power spectral densities (PSD) in the low frequency range withgood correlation to ight test data. However, due to the boundary con-ditions in the test, and the single-axis excitation approach, mechanicalvibration tests cannot accurately reproduce ight-related vibrations inall three directions. The acoustic test did less good in exciting the lowfrequencies, but provided a good excitation, in all three directions, in themid frequency range, up to 3kHz. The control approach in the acoustictest could not perfectly mimic the ight acoustic PSD throughout thewhole frequency range. It thus remains as future work to study and testother control approaches. The study provides a basis for future acoustictests that will aim at predicting component loads as measured in captiveight, possibly together with acoustic simulations.