A QUICK LOOK AT FLIGHT DATA FROM A DIGITAL DAMAGE DOSIMETER

摘要

The Air Force Research Laboratory (AFRL) sponsored flight tests using on-board state-of-the-artrndigital data recorders called damage dosimeters to measure temperature and vibration data in areas ofrnacoustic fatigue on the B-52, F-15 and C-130 aircraft. The damage dosimeter, designed by The BoeingrnCompany, measures structural strains and temperatures on in-service aircraft to diagnose difficult-toanalyzernstructural conditions, such as acoustics and high cycle fatigue. These tests were part of an AFRLrnStructural Technology and Analysis Program (STAP) to support the durability patch design process tornrepair structural cracks in secondary structure. The dosimeter measures temperature and 3 dynamicrnstrains for use in the design of damped durability patches. It is a rugged, small, lightweight datarnacquisition unit that runs off of battery power in an autonomous fashion. The damage dosimeter quicklyrnmeasures 3 channels of strain at sample rates as high as 15 kilo-samples per second and a single channelrnof temperature at a sample rate of 1 per 1.3 seconds. The dosimeter only acquires data above arnprogrammer defined rms strain threshold and is currently programmed to store 42 records of time historyrndata each 0.3 seconds long. In addition it is programmed to record and store third octave spectra in its 4-rnmegabyte memory until filled. The damage dosimeter merges the functionality of both the analog signal