MA600F后机身疲劳试验加速技术研究

Acceleration Technology of Fatigue Test for MA600F Rear Fuselage

民用飞机为取得型号合格证,按照适航规章必须进行全机疲劳试验,而在常规试验技术下,新一代涡桨支线飞机MA600F后机身疲劳试验周期过长、且费用消耗高,将影响到适航取证和服役使用。开展MA600F后机身疲劳试验加速研究,可尽早取得适航许可以投入商用,同时为设计和制造工艺的优化改进提供支撑,具有产生巨大经济价值和提升试验技术的重要意义。根据后机身疲劳试验加载情况设计了一体化自平衡加载框架,以快速完成安装、维护和巡检,并进行了有限元校核。结合细节疲劳额定值(DFR)法和线性损伤累积理论建立了等损伤折算的载荷谱简化方法,并提出了一种基于非线性规划的载荷整体平衡优化方法。将上述加速方法先后应用于小试验件和MA600F后机身疲劳试验,小试验件的循环次数减少了约98%,寿命结果处于合理范围内;后机身加速试验在15000次起落出现了裂纹损伤,与全机常规试验25000次起落的损伤结果基本相同。

The civil aircraft must undergo the full-scale fatigue test according to the airworthiness regulations,so as to obtain the type certificate.The new generation turboprop regional aircraft MA600F rear fuselage fatigue test needs too long period and high cost under the conventional technology,which affects the airworthiness certification and service use.Carrying out accelerated research on fatigue test of MA600f rear fuselage can obtain airworthiness permit and be put into commercial use as soon as possible.At the same time,it provides support for the optimization and improvement of design and manufacturing process,which is of great economic value and great significance to improve test technology.An integrated loading frame was designed according to the loading situation of rear fuselage fatigue test to complete installation,maintenance and inspection quickly.The equivalent damage conversion method was established to simplify the load spectrum based on detail fatigue rating(DFR)and liner damage accumulation theory.The overall load balance optimization was proposed based on nonlinear programming.The two above acceleration methods were applied to the fatigue test of small test pieces and MA600F rear fuselage.The cycles number of small test pieces is reduced by about 98%,and the fatigue life results are within engineering reasonable range.The crack damage of the rear fuselage acceleration test occurs during 15000 cycles,which is basically the same as the damage result of 25000 cycles in the conventional full-scale fatigue test.