Comparison of structural response and fatigue endurance of aircraft flap-like box structures subjected to acoustic loading

Abstract

The results of an extensive test program to characterize the behavior of typical aircraft structures under acoustic loading and to establish their fatigue endurance are presented. The structures tested were the three flap-like box-type of structures. Each structure consisted of one flat (bottom) and one curved (top) stiffener stiffened skin panel, front, and rear spars, and ribs that divided the structures into three bays. The three structures, constructed from three different materials (aircraft standard aluminum alloy, Carbon Fibre Reinforced Plastic, and a Glass Fibre Metal Laminate, i.e., GLARE) had the same size and configuration, with only minor differences due to the use of different materials. A first set of acoustic tests with excitations of intensity ranging from 140 to 160 dB were carried out to obtain detailed data on the dynamic response of the three structures. The FE analysis of the structures is also briefly described and the results compared with the experimental data. The fatigue endurance of the structures was then determined using random acoustic excitation with an overall sound pressure level of 161 dB, and details of crack propagation are reported.

Active health monitoring of an aircraft wing with embedded piezoelectric sensor/actuator network: I. Defect detection, localization and growth monitoring

“…Under high cyclic loads or corrosive environment, fatigue cracks may initiate from the rivet holes and go span-wise along the stiffeners or spars. Xiao et al [19] reported their study on the fatigue endurance of three aircraft flap-like box structures made of various materials (aluminium alloy, CFRP and GLARE) under acoustic loading. NDT examinations are still needed to characterize those defects.…”

Fatigue crack growth analysis of a reinforced cylindrical shell under random loading

“…Ustilovsky and Arone tested multi‐crack panel‐type aluminium specimens under constant amplitude loading, constant amplitude with superimposed overloads and random variable amplitude load history. Xiao et al presented an extensive test programme to characterize the behaviour of typical aircraft structures under random acoustic loading and to establish their fatigue endurance. The structures tested were the three flap‐like box‐type structures.…”