DAMAGE TOLERANCE IN HELICOPTERS REPORT ON THE ROUND ROBIN CHALLENGE

摘要

This paper describes a Round Robin exercise to establish fatigue lives and inspection intervals for a helicopter airframe aluminium alloy component using crack growth analytical methods. Participants were given geometry, stress intensity solution, crack growth data and load spectrum data for the component. Twelve organisations, from three continents, participated in the exercise and produced twenty seven predictions using eight different software analysis packages. The predicted component lives ranged from 240 flight hours up to over 12,500 flight hours. Two experimental validation tests were carried out on the specified component under the specified loading spectrum which produced very similar growth curves and resulted in lives of 420 and 440 flight hours. Reasons for the variation in analytical predictions and experimental results are cited and discussed.