フライトシミュレーション荷重下における2024-T3 Al合金の疲労き裂進展挙動

抄録

Flight-simulation tests were carried out using 2024-T3 specimens with constant gust cycles, and with the addition of a single overload at either the beginning or the end of each flight. Also, the effects of the stress level of the ground load on the fatigue crack propagation behavior were examined. The purpose was to reveal crack growth interaction effects (retardations and accelerations), and to measure the crack opening stress under variable amplitude loading, which might support crack growth prediction techniques. From the experimental results, the following conclusions were obtained. The crack growth retardations can occur by sequence effects. The crack propagation rate was closely related to the crack closure behavior of gust cycles in flight-simulation tests. The fracture surface transition from tensile mode to shear mode cracking was observed.